CA1206637A - Switching device connectable to a subscriber's telephone line - Google Patents
Switching device connectable to a subscriber's telephone lineInfo
- Publication number
- CA1206637A CA1206637A CA000431663A CA431663A CA1206637A CA 1206637 A CA1206637 A CA 1206637A CA 000431663 A CA000431663 A CA 000431663A CA 431663 A CA431663 A CA 431663A CA 1206637 A CA1206637 A CA 1206637A
- Authority
- CA
- Canada
- Prior art keywords
- switching
- telephone line
- relay
- line
- switching apparatus
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
- H04M11/007—Telephonic communication systems specially adapted for combination with other electrical systems with remote control systems
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B31/00—Arrangements for the associated working of recording or reproducing apparatus with related apparatus
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- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Automation & Control Theory (AREA)
- Signal Processing (AREA)
- Devices For Supply Of Signal Current (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE:
A switching apparatus connectable to a normal subscriber's telephone line and including a plurality of connectors for connecting at least one external system, such as a T.V. set, a tape recorder, a radio receiver and the like. The apparatus comprises a first switching device including a circuit for detecting conditions on the tele-phone line, and a first electrical supply including at least one of said connectors. The first switching device connects said at least one connector to, or disconnects it from an electrical power source depending on the detected conditions.
A second switching device is activated by the first switch-ing device after detection by the detecting circuit of a first condition amongst said conditions. There is also pro-vided a circuit for deactivating the second switching device upon occurrence of a release signal on the line, and a circuit for simulating a second condition on the line. The second switching device interconnects the simulating circuit with the line when said second switching device is activated.
Another circuit controlled by the first and second switching device is provided for a bidirectional transmission of information signals between the line and the external system connected to the switching apparatus. The apparatus may also comprise a second electrical supply including another connector, and a third switching device for connecting said other connector to, or disconnecting it from the electrical power source. The third switching device is controlled by a circuit which preferably includes two timers. Such a switching apparatus can be used for switching on or switching off the system connected thereto and/or for establishing connections between this system and the telephone line in relation with the conditions present on the line.
A switching apparatus connectable to a normal subscriber's telephone line and including a plurality of connectors for connecting at least one external system, such as a T.V. set, a tape recorder, a radio receiver and the like. The apparatus comprises a first switching device including a circuit for detecting conditions on the tele-phone line, and a first electrical supply including at least one of said connectors. The first switching device connects said at least one connector to, or disconnects it from an electrical power source depending on the detected conditions.
A second switching device is activated by the first switch-ing device after detection by the detecting circuit of a first condition amongst said conditions. There is also pro-vided a circuit for deactivating the second switching device upon occurrence of a release signal on the line, and a circuit for simulating a second condition on the line. The second switching device interconnects the simulating circuit with the line when said second switching device is activated.
Another circuit controlled by the first and second switching device is provided for a bidirectional transmission of information signals between the line and the external system connected to the switching apparatus. The apparatus may also comprise a second electrical supply including another connector, and a third switching device for connecting said other connector to, or disconnecting it from the electrical power source. The third switching device is controlled by a circuit which preferably includes two timers. Such a switching apparatus can be used for switching on or switching off the system connected thereto and/or for establishing connections between this system and the telephone line in relation with the conditions present on the line.
Description
The present invention relates to a versatile switching apparatus connectable to a normal subscriber's telephone line, for interconnecting this telephone line, in relation with conditions present thereon,and/ox an electri-cal power supply to any external system connected thereto.
Such a switching apparatus may, for example, switch on or off the external system, and/or establish connections for allowing this system to receive information signals from the telephone line or to transmit such signals to the tele -phone line.
Switching devices of t~e type described above are presently available on the market under the popular desig-nation of atelephone answering systems. These known, telephone answering systems are efficient but they are only designed for responding to a telephone call and registering a message. They are not connectable to another external system such as a T.V. set, a tape recorder, a radio-receiver for switching it on or off and/or for establishing inter-connections between the system and the telephone line.
Other switching devices generally called modem are also known and used to connect a data terminal equipment to a telephone line. Such modems are designed for modulating and demodulating data words. ~owever, these modem do not comprise means for switching on or swi~ching off any kind of external equipment in response to conditions present on the telephone line.
The object of the present invention is therefore to provide a switching device of the above descrlbed type which is not limited to only one application, but may be used in a plurality o~ applications according to the con-summerls re~uirements or needs.
More particularly, the present invention proposes a switching apparatus connectable to a subscriber's tele-phone line and including a plurality of connecting means 6~3~9 for connecting at least one external, electrically operated system. This swi-tching apparatus basically comprising:
first switching means including means for detect-ing conditions on the telephone line, these detecting means controlling op~ration of the first s~itchi.ng means in rela-tion with the conditions on -the line;
first supply means including first connecting means forming part of the plurality of connecting means, these first connecting means being connected to or discon-nected from an electrical power source by the first switch-ing means depending on the detected conditions;
second switching means activated by the first switching means after detection by the detecting means of a first condition amongst the conditions on the line;
means for deactivating the second switching means upon occurrence of a release signal on the telephone line;
means f-or simulating a second condition amongst the conditions on the telephone line, these simulating means being interconnected with the telephone line by the second switching means when these second switching means are activated; and means for transmitting an incoming information signal from the telephone line to second connecting means forming part of the plurali.ty of connecting means, and for transmitting an outgoing information signal from third con-necting means forming part of the plurality of connecting means to the telephone line.
These transmitting means comprises first means for transmitting the incoming information signal from the telephone line to the second connecting means, the first transmitting means being connected to the telephone line by the first switching means after detection by the detecting means of the second condition, or disconnected from the telephone line by the first switching means after detection ~663~
by the detecting means of a third condition amongst these conditions. The transmitting means also comprises second means for transmitting the outgoing information signal to the telephone line from the third connection means, these second transmitting means being connected to or disconnected from the telephone line bv the second switching means when the second switching means are activated and deactivated, respectively.
In operation, the swi-tching appara-tus connects the external system to, or disconnects it ~rom the electri-cal power source through the first connecting means when such system is connected to the first connecting means. The switching apparatus also connects the system to or discon-nects it from the telephone line through the second and/or third connecting means when such system is connected to these second and/or third connecting means.
In a preferred embodiment, the switching apparatus comprises third switching means and second supply means in-cluding fourth connecting means, this third switching means connecting the ~ourth connecting means tol or disconnecting it from the electrical power source.
In another preferred embodiment of the invention, the switching apparatus comprises first timiny means for activating the third switching means within a predetermined period of time after the second switching means are acti-vated for connecting the power source to the second connect-ing means until the second switching means are deactivated.
In a further preferred embodiment of the present invention, the switching apparatus comprises second timing means~ activated by the first timing means at the same time the third switching means are activated by these first timing means in order to activate the third switching means for connecting the power source to the fourth connecting means during a predetermined period oE time whenever the ~ Ei63~
second switching means are activated or not, and means for adjusting this predetermined period of time.
The first condition may be a ringing voltage.
The second condition may be a condition present on the telephone line when a telephone receiver connected thereto is in an ofE-hook position. The remaining conditions may also comprise a dial pulse train and a condition present on the line when the receiver is in an on-hook position.
The objects, advantages and other features of the present invention will become apparent Erom the following, non-restrictive description of a preferred embodiment thereof, made with reference to the accompanying drawings in which:
Figures 1 and 2 show the circuit of a switching apparatus according to the present invention; and Figures 3 to 8 illustrate some examples of appli-cations of the switching apparatus of Figures 1 and 2.
As shown in Figure 1, the apparatus according to the invention which is numbered 160 in Figures 3 to 8, com-prises a power supply circuit including a transformer Thaving its primary winding connected to a 120 Volts A.C.
source through a plug P, a switch S and a fuse F. The secondary winding of the Transformer T is connected to the input of a bridge rectifier circuit including four diodes D. The output of the bridge rectifier circuit supplies a full wave rectified voltage to a capacitor C. The DC volt-a~e through the capacitor C is applied to a ZEN~R diode Z
through a resistor R in order to regulate the DC voltage supplying the circuit of the switching apparatus according to the present invention. This type of DC power supply circuit is well l~nown in the art and will not be further elaborated.
The DC power supply circuit is Eollowed by a first circuit section 9 of the swi-tching apparatus accord-~2~ 3~
ing to the invention. The first section 9 is used for detectiny conditions present on an incoming subscriber's telephone line 10. The firs-t section 9 can also be used for operating -the switching apparatus for a given period of time depending on the position of the switch S which is a double pole double throw switch. On both positions of the switch S, the primary winding of the transformer 1 is supplied by the 120 Volts A.C. source. According to an AUTO>~ or TIMER position of the switch S, a capacitor 29 or the incoming line 10 is connecte~ to the base of a transistor 11 through a resistor 12, a diode 13 and a first pair of contacts A2 f an electromagnetic relay A2 which are normally closed IN.C.) when the coil 16 of the relay A2 is not energized.
In the present description, N~O. contacts relate to contacts of a relay which are normally open when the coil of this relay is not energized while N.C. contacts relates to contacts of a relay which are normally closed when the coil of that relay is not energized.
The collector of the transistor 11 is connected to the DC positive voltage present at the cathode of the ZENER diode Z of the DC power supply circuit through a resistor 17 while its emitter is connected to the ground and the base of a transistor 14 through resistors 18 and 19, respectively.
When the transistor 11 is conducting, the base of the transistor 14 is supplied with a current which energizes the coil 15 of an electromagnetic relay Al through the collector-emitter conductive path of the transistor 14. A
protecting diode 20 is mounted in parallel to this coil 15.
The coil 16 of the electromagnetic relay A2 has one of its terminal connected to the DC positive voltage generated by the D.C. power supply. It can be energized through a transistor 23 or a manual switch 27 bokh mounted 3~
between the other termlnal of the coil 16 and the ground of the DC power supply which is also the ground of the circuit of the switching apparatusO The switch 27 is de-pressed when a user wants to initiate operation of the switching apparatus inherent to the energization of the relay A2 as will be explained in details hereinafter. The switch 27 energizes the coil 16 through a resistor 25 and a capacitor 26 connected in parallel and disposed between the switch 27 and said other terminal of the coil 16 having a protecting diode 28 mounted in parellel thereto.
The conduction of the collector-emitter path of the transis-tor 23 is controlled through its base by the action of a network comprising a resistor 24, a capacitor 22, and a first pair of N.C. contacts Al of the relay Al, intercon-necte~ as s~own on Figure 1 an~ mounted between the base of the transistor 23 and the DC positive supply voltage. A
first pair of N.O. contacts Al of the relay Al and a resistor 21 are provided for dlscharging the capacitor 22 when the relay Al is energized.
When the switch S is in the position auto and the subscriber's line 10 is in a normal condition, corre-sponding to a condition present on the line when a telephone receiver connected thereto is in an on hook position, a capacitor 29 stores energy from a DC voltage of 4B V avail-able on the line 10 through a high resistance path formed by a diode 31 and a resistor 30. The diode 31 prevents the voltage through the capacitor 29 from affecting signals on the line 10. After five time constants which are determined by the values of the resistor 30 and the capacitor 29, the capacitor 29 is completely charged to the same voltage level of 48 V as the line 10, and when the position of the switch S is subsequently selected to TIMER, the energy stored in the capacitor 29 is sufficient to keep the coil 15 of the relay ~1 energized during a period of time determined by the 6~
RC time constant of the capacitor 29 and the input imped-ance of the network involving the transistors 11 and 14, by supplying a base current to the transistors 11 and 14 through the switch S, the contacts A2 ~ the diode 13 and the resistor 12. The value of the capacitor 29 is selected for this purpose.
This time-operation of the swi-tching apparatus 160 may be used for timel.y energizing for example a TV
receiver 161, ~s shown on Figure 3, through an ~.c. outlet 32 having, as illustrated on Figure 1, a first contact connected to the plug P through the switch S and a second contact connected to the plug P through the fuse F, a switch 33 having its position appropriately selected, and a second pair of N.O. contacts Al of the relay Al. When the capacitor 29 is discharged, the coil 15 is de-energized, thereby opening contacts Al . This opening consequently de-energizes the TV receive3 supplied through the outlet 32.
As can be seen on Figure 1, relays Al and A2 are interconnected in a time delay flip flop configuration When the switch S is in its position aAUTO, this configura-tion senses conditions present on the subscriber's line 10 such as a ringing voltage, dial pulse trains, an on hook or off hook conditions of a telephone receiver connected to this line 10, etc... .
The following explanations will now be given, assuming that the switch S is in its AUTO positionO
As mentioned above, when the subscriber's tele-phone line 10 is in a normal idle condition, which condition corresponds to an on hook position of a telephone receiver connected to the line without no incomi.ng ringing voltage, a permanent 4~ V DC voltage is available rom -the line 10.
This 48 V DC voltage supplies a base current to the tran-sistors 11 and 14 through the N.C. contacts A2 / the diode 13 and the resistor 12~ thereby keeping the relay Al ener-3~
gized and the relay A2 de-energized through the N.C.
contacts A12-When other conditions occurs on the line 10 suchas a ri.nging voltage, a dial pulse train or a 6 Volts DC
voltage corresponding to an of-f hook position of -the telephone receiver, the relays Al and A2 carry acknowledg-ment of such conditions. More particularly, ~he coil of the relay A1 is instantaneously de-activated due to an at least momentarily decrease of the voltage on the line 10 under a certain level due to the network involving resistors 12, 18 and 19 and transis-tors 11 and 14. The N.C. contacts A12 are then closed, thereby energizing ~he coil 16 of relay A2 by supplying a base current to the transistor 23 through the capacitor 22 and the resistor 24.
As illustrated on Figure 4, the AcC. outlet 32 of Figure 1 may be used to supply, for example, a radio receiver 151 through the N.O. contacts A13 by appropriately selecting the position of the switch 33 as long as a perma-- nent 48 V DC voltage is present on the line 10. On the occurrence of a ringing vo'tage on the line 10, the de-energization of the coil 15 of the relay Al opens the N.O.
contacts A13 for automatically disconnecting the radio receiver 151 upon receival of a call and for also automati-cally re-connecting this radio receiver after the receiver returns in its normal on hook position and the permanent 48 V voltage is re-established on the line.
The opening of the N.C. contacts A2 as the relay A2 is energized, prevents the relay Al from following the ringing voltage occurring on the line or possibly a dial pulse train transmitted on the line 10 by a receiver con-nected to this line.
The relay A2 is time delay operated since the base current of the transistor 23 energ.izing the coil 16 of this relay, can flow through the capacitor 22 only until ~:0~3~
the latter is completely charged. Therefore, during a relatively long off hook condition of a receiver connect-ed to the line 10, i.e. with a 6 ~olts DC voltage present on the line lO, both relays Al and A2 becomes deactivated.
It should be noted that with the system of Figure 4, as the relay Al is also de-energized in response to an off hook position of a telephone receiver connected to the line 10, the radio receiver 151 is switched off when this receiver is in an off hook position and switched on when this receiver is in an on hook position.
As already stated above, every time the coil 15 of the relay Al is energized, the N.O. contacts All are closed thereby discharging in a closed loop the capacitor 22 through the resistor 21 as the N.C. contacts A12 are open at that time.
The A.C. outlet 32 may also be used to supply any o-ther external systeml when the coil 15 of the relay Al is de-energized in response to the above-defined conditions on the line lO, through a second pair of N~C. contacts Al of the relay Al, by appropriately selecting the position of the switch 33.
The switching apparatus of the invention comprises a second section 34 shown on Fi~ure 1 for displaying an actual operation thereof. This second section comprises two light emitting diodes (LED) 39 and 47 which monitor the switching device operation.
More particularly, these two LEDIs display the positions of the contacts of the relays Al and A2 as well as the position of the contacts of a relay A4, and thereby they display the operation of the switching apparatus. The operation of the relay A4 will be defined in detail herein-after.
If the relay Al is energized and therefore a third pair of N.O. contacts Al of this relay are closed, ~L2~3~
the LED 39 is activated through a resistor 38 for dis-playing the operation of this relay. A protecting resistor 37 is moun-ted in paralle] with this LE~ 39.
In the occurrence on the telephone line 10 of a ringing voltage or an ~off hook position of a telephone receiver connected thereto, the coil 15 of he relay Al is de-activated and therefore a third pair of N.C. contac~s Al of this relay are closed for energi~ing the LED 4 7 through a resistor 48 for displaying the operation of the switching apparatus. Another protecting resistor 26 is also mounted in parallel to the LED 47.
After the subscriber's line 10 returns to its normal idle condition, i.e. to a DC voltage of ~8 V., the LED 39 is energized as the N.O. contacts Al closes due to the energization of the relay Al. The LED 47 also stays lighted due to the 1ip-flop action of transistors 42 and 43. The circuit including these transistors 42 and 43 also includes resistors 44, 45 and 49 interconnected as shown on Figure 1, as well as a switch 41 acting as a reset switch i~e. when the switch 41 is depressed, the LED 4 7~ is switched off. This LED 47 stays activated for the purpose of memorization.
When the relay A4 is energized, a first pair of N.O. contacts A~l of this relay is closed and N.O. contacts ~5 Al are open as the relay Al is at that time de-energized as will be seen hereinbelow. This position of the contacts A4 and Al allows the network formed by an unijonction transistor 40, a resistor 36 and a capacitor 35 to produce an intermittent lighting of the LED 39 to indicate the energization of the relay A4 and therefore the operation of the switching apparatus.
A third section 51 of the switching device shown on Figure 1 comprises an incoming and an outgoing paths for the audio or information signals both connected to the :~L2~16 i63~
telephone line lO throuyh the switch S.
The incoming path comprises two possible paths, a first path through a first pair of N.O. contacts A2 oE
the relay A2, a DC coupling capacitor 58 a resistor 57, a potentiometer 53 and an output jack connection Jl, and a second path through a second pair of N.~. contacts A2 of the relay A2, a fourth pair of N.C. contacts A18 of the relay Al, a DC coupling capacitor 54, the potentiometer 53 and the output jac~c Jl.
The audio signals are normally routed across the second path of the incoming path while the capacitor 58, the resistor 57 and the potentiometer 53 of its first path form a high impedance circuit for routing an incorning ringing voltage from the telephone line 10, as the relay A2 is energized for closing its contacts A2 upon occurrence of such a ringing voltage.
Referring now to Figure 6 of the drawings, a radio receiver 163 and a tape recorder 164~both supplied throuyh the N.C. contacts A14, the switch 33 and the A.C. outlet 32 and having their audio inputs both connected to the jack connection Jl of the switching apparatus 160, can be used for amplifying and recording a telephone conversation between a telephone receiver connected to the line lO and another remote telephone receiver, as well as for amplifying or recording any other audio signals from the line lO.
Of course, the switching apparatus 160 may also be used for visualizing signals present on the line lO on the screen of a cathode ray tube oscilloscope. In that case the signal input of the oscilloscope is connected to the jack connection Jl, as shown on Figure 8.
The outgoing path of the section 51 is formed by a second jack connection J2, a DC coupling capacitor 55 and a second pair oE N.O. contacts A4 of the relay A~. A re~
sistor 56 forming part of another section 52 of the switching 3~
apparatus has one of its terminals connected between the capacitor 55 and ~che contac~s A4 while its other t~rminal is yrounded. This resistor 56 is provided for simula-ting a condition on the telephone line, which condition corresponds to a condition present on the line 10 when a receiver con-nected thereto is in an off hook position, for establishing a ~oop in the telephonic network with a remote telephone receiver upon receipt of a call or ringing voltage therefrom.
The net~rk includin~ the jack J2, the capacitor 55 and the N.O. contacts A4 forms a path for transmittiny audio signals or other information signals to the telephone line 10 during the relay A4 of the switching apparatus is energized and therefore when this network and the simulating resistor 5b are connected to the line through the N.O. con-tacts A43-As above mentioned, the switching apparatus according to the present invention may include a fourth sec-tion 52 shown in Figure 1~
The circuit of the section 52 comprises the coils 84 and 85 of an electromagnetic relay A3 and the electro-magnetic relay A4, respectively, which relays are respec-tively responsible of the disconnection and the connection of the resistor 56 to the line 10 and at the same time of the outgoing transmission path through contacts A~ .
As set forth hereinabove, when an incoming ringing voltage is present on the telephone line, the relay Al becomes de-energized while the relay A2 becomes energized for a period of time determined by the capacitor 22 and the re-sistor 24 of Figure 1. A second pair of N.O. contacts A23 of the relay A2 are therefore closed upon energization of this relay.
An incoming ringing voltage from the line 10 stores a DC voltage across a capac.itor 64, through a resi.stor 62 by energizing the relay A2 which closes its N.O. contacts A23.
- 12 ~
~QI~;~i3~
The resistor 62 in combination with a resistor 65 fixes the maximum D.C. voltage level thro~gh the capacltor 64.
This maximum voltage is modified by a low value resistor 66 upon energization of the relay A~,which closes its third pair of N.O. contacts A4 ~during the time the N.O. contacts A2 remains closed As shown on Figure l, the voltage across the capacitor 64 supplies a current to the base of the transis-tor 77 through a network comprising in series a diode 6~, a potentiometer 69, a resistor 70, and a resistor 78 mounted in parallel with a first pair of N.C. contacts A42 of the relay A4-The current routed from the capacitor 64 to the base of the transistor 77 is transformed into a correspond-ing voltage due to the integrating action of a capacitor 72 mounted in parallel with a resistor 73 between the ground and the base of this transistor 77.
The time required for charging the capacitor 64 as well as the nature of the base network of the transistor 77 determines the time at which the ringing voltage from the line lO must be generated before the coil 85 of the relay A4 is energized through the transistor 77 for connecting the simulating resistor 56 to the line lO and thereby establish-ing the above defined loop. The coil 85 of the relay A4 has a protecting diode 82 mounted in parallel thereto. The resistance value of the potentiometer 69 may be varied to adjust the time required by the ringing voltage before ener-gization of the relay ~4, or before establishment of the loop by connection of the resistor 56 to the line lO.
As soon as the voltage across the capacitor 72 is equal to the bias voltage required by the base-emitter of the transistor 77 for making conductive its collector-emitter path, the relay A~ is energized.
As illus-trated on Figure l, the fourth section 52 6~7 also includes a transistor 91 through which the coil 84 of the relay A3 is energized or de-activated. This coil 84 is energized through a circuit formed by the collector-emitter conductive path of the transistor 91 and the three diodes 60, 61 and 86 serially connected as shown on Figure 1. A
protective diode 87 is mounted in parallel with the coil 84.
The conduction of this transistor 91 is controlled through its base by the voltage present at a point N through a net-wor~ formed by a diode 88, a resistor 89, a potentiometer 90 and a capacitor 92. The coil 84 can also be energized t}lrough a manual switch 83 mounted as shown in the drawings.
Upon energization of the coil 85 of the relay A4 through the collector-emitter conductive path of the tran-sistor 77 and diodes 74 to 76, the N.O. contacts A4 are closed and a current from the line 10 flows through the resistor 56 for simulating, as mentioned above, an off hook condition of a telephone receiver connected to this line 10 by establishing the loop. The value of the resistor 56 is selected to establish the nominal aoff hook current of a telephone receiver whan it loads the telephone line 10.
The coil 84 of the relay A3 becomes activated as the voltage present across the resistor 56 or on the line 10 supplies a base current to the transistor 91 through the diode 88, the resistor 83 and the potentiometer 90. When the relay A~ is energized and the relay A2 is not energized therefore having its NØ contacts A2 open the capacitor 64 is dis-charged through the low valve resistor 66 and the third pair of N.O. contacts A~ of the relay A4 which are closed.
When the N.O. contacts A~ are closed upon energization of the relay A4, the relay A4 remains energized as the tran-sistor 77 receives a base current through a capacitor 80, a resistor 79 and a first pair of N.O. con-tacts A31 of the relay A3 which are closed when the relay A3 is energized. The capacitor 80 and the resistor 3~
79 automatically generate a 2 minutes simulation of an off hook condition by the resistor 56 as the relay A~ is time-deactivated by this resis-tor 79 and the capacitor 80 A resistor 81 in combination with a second pair of N.C. contacts A4 oE the relay A4 or a resistor 59 in combination with a switch Sw both form a current discharge path for the capacitor 30.
The function of the N.O. contacts A3 at the base of the transistor 77 is exclusively to de-energi~e the relay A4 in response to any release sig`nal from the line 10 which is detected by the circuit associated to the relay A3 and connected to the line 10. This release signal is a signal having a lower value than about 6 V. The relay A3 together with its associated circuit are therefore sensitive to changes in the impedance of the line 10 through the resistor 56, i.e. in the voltage level present across this resistor or present on the line at the subscriber's location. The transistor 91 is not affected by any audio or information signals transmitted to or received from the line 10 due to the action of the capacitor 92. The relay A4 is de-energized and therefor the connection of the resistor 56 to the line 10 is released in response to such a release>~ signal from the line 10 which is acknowledged by the transistor 91 which de-energizes the coil 84 of the relay A3 and thereby the coil 85 of the relay A4 through the N.O. contacts A3 of the relay A3. The potentiometer 90 is adjusted for matching the imped-ance of its associate circuit with the impedance of the telephone line 10.
The simulation of the off-hook condition of a telephone receiver connected to the line 10 is possible in both normal (NOR) or expand ~EXP) position of the switch Sw.
With the switch Sw in its normal position NOR, the operation of the switching apparatus of the invention is as described above. Conse~uently, -the switch Sw is placed 63~
at its position NOR if a rel.atively short time of operation is needed. In this case, the switching apparatus simulates during a prede-termined period of time the off-hook>~ condi-tion.
With the switch Sw in its position NOR, the switching apparatus 160 of the present invention may be used for automatically transmit-ting audio or information signals from a tape recorder 162 to the telephone l.ine 10 through the connection J2 and the ou-tgoing path of the sec-tion 51 upon receipt of a telephone ringing voltage as diagrammatically shown on Figure 5.
In this case, the ~.C. cord of the tape recorder is connected to the AC outlet 32 supplying electrical power through W.C. contacts Al by appropriately selecting the position of the switch 33. As described above, after the reception a telephone ringing voltage from the line 10, the relay Al is de-energized and the relay A~ is energized there-by closing contacts Al and A4 for allowing the above-mentioned tranmi.ssion.
With the switch Sw in its position EXP, the opera-tion of the switching device is -the same as in its position NOR except that other contacts Sw of this Switch Sw are closed thereby supplying a base current to the transistor 77 through the resistors 59 and 79, and the N.O.
contacts A3 when the relay A3 is energized. These contacts Sw also supply power to a fifth .section of the switching apparatus through a point WO This fiEth section is designed for expanding the possibilities of the switching apparatus.
This fi:Eth section which is illustrated on Figure
Such a switching apparatus may, for example, switch on or off the external system, and/or establish connections for allowing this system to receive information signals from the telephone line or to transmit such signals to the tele -phone line.
Switching devices of t~e type described above are presently available on the market under the popular desig-nation of atelephone answering systems. These known, telephone answering systems are efficient but they are only designed for responding to a telephone call and registering a message. They are not connectable to another external system such as a T.V. set, a tape recorder, a radio-receiver for switching it on or off and/or for establishing inter-connections between the system and the telephone line.
Other switching devices generally called modem are also known and used to connect a data terminal equipment to a telephone line. Such modems are designed for modulating and demodulating data words. ~owever, these modem do not comprise means for switching on or swi~ching off any kind of external equipment in response to conditions present on the telephone line.
The object of the present invention is therefore to provide a switching device of the above descrlbed type which is not limited to only one application, but may be used in a plurality o~ applications according to the con-summerls re~uirements or needs.
More particularly, the present invention proposes a switching apparatus connectable to a subscriber's tele-phone line and including a plurality of connecting means 6~3~9 for connecting at least one external, electrically operated system. This swi-tching apparatus basically comprising:
first switching means including means for detect-ing conditions on the telephone line, these detecting means controlling op~ration of the first s~itchi.ng means in rela-tion with the conditions on -the line;
first supply means including first connecting means forming part of the plurality of connecting means, these first connecting means being connected to or discon-nected from an electrical power source by the first switch-ing means depending on the detected conditions;
second switching means activated by the first switching means after detection by the detecting means of a first condition amongst the conditions on the line;
means for deactivating the second switching means upon occurrence of a release signal on the telephone line;
means f-or simulating a second condition amongst the conditions on the telephone line, these simulating means being interconnected with the telephone line by the second switching means when these second switching means are activated; and means for transmitting an incoming information signal from the telephone line to second connecting means forming part of the plurali.ty of connecting means, and for transmitting an outgoing information signal from third con-necting means forming part of the plurality of connecting means to the telephone line.
These transmitting means comprises first means for transmitting the incoming information signal from the telephone line to the second connecting means, the first transmitting means being connected to the telephone line by the first switching means after detection by the detecting means of the second condition, or disconnected from the telephone line by the first switching means after detection ~663~
by the detecting means of a third condition amongst these conditions. The transmitting means also comprises second means for transmitting the outgoing information signal to the telephone line from the third connection means, these second transmitting means being connected to or disconnected from the telephone line bv the second switching means when the second switching means are activated and deactivated, respectively.
In operation, the swi-tching appara-tus connects the external system to, or disconnects it ~rom the electri-cal power source through the first connecting means when such system is connected to the first connecting means. The switching apparatus also connects the system to or discon-nects it from the telephone line through the second and/or third connecting means when such system is connected to these second and/or third connecting means.
In a preferred embodiment, the switching apparatus comprises third switching means and second supply means in-cluding fourth connecting means, this third switching means connecting the ~ourth connecting means tol or disconnecting it from the electrical power source.
In another preferred embodiment of the invention, the switching apparatus comprises first timiny means for activating the third switching means within a predetermined period of time after the second switching means are acti-vated for connecting the power source to the second connect-ing means until the second switching means are deactivated.
In a further preferred embodiment of the present invention, the switching apparatus comprises second timing means~ activated by the first timing means at the same time the third switching means are activated by these first timing means in order to activate the third switching means for connecting the power source to the fourth connecting means during a predetermined period oE time whenever the ~ Ei63~
second switching means are activated or not, and means for adjusting this predetermined period of time.
The first condition may be a ringing voltage.
The second condition may be a condition present on the telephone line when a telephone receiver connected thereto is in an ofE-hook position. The remaining conditions may also comprise a dial pulse train and a condition present on the line when the receiver is in an on-hook position.
The objects, advantages and other features of the present invention will become apparent Erom the following, non-restrictive description of a preferred embodiment thereof, made with reference to the accompanying drawings in which:
Figures 1 and 2 show the circuit of a switching apparatus according to the present invention; and Figures 3 to 8 illustrate some examples of appli-cations of the switching apparatus of Figures 1 and 2.
As shown in Figure 1, the apparatus according to the invention which is numbered 160 in Figures 3 to 8, com-prises a power supply circuit including a transformer Thaving its primary winding connected to a 120 Volts A.C.
source through a plug P, a switch S and a fuse F. The secondary winding of the Transformer T is connected to the input of a bridge rectifier circuit including four diodes D. The output of the bridge rectifier circuit supplies a full wave rectified voltage to a capacitor C. The DC volt-a~e through the capacitor C is applied to a ZEN~R diode Z
through a resistor R in order to regulate the DC voltage supplying the circuit of the switching apparatus according to the present invention. This type of DC power supply circuit is well l~nown in the art and will not be further elaborated.
The DC power supply circuit is Eollowed by a first circuit section 9 of the swi-tching apparatus accord-~2~ 3~
ing to the invention. The first section 9 is used for detectiny conditions present on an incoming subscriber's telephone line 10. The firs-t section 9 can also be used for operating -the switching apparatus for a given period of time depending on the position of the switch S which is a double pole double throw switch. On both positions of the switch S, the primary winding of the transformer 1 is supplied by the 120 Volts A.C. source. According to an AUTO>~ or TIMER position of the switch S, a capacitor 29 or the incoming line 10 is connecte~ to the base of a transistor 11 through a resistor 12, a diode 13 and a first pair of contacts A2 f an electromagnetic relay A2 which are normally closed IN.C.) when the coil 16 of the relay A2 is not energized.
In the present description, N~O. contacts relate to contacts of a relay which are normally open when the coil of this relay is not energized while N.C. contacts relates to contacts of a relay which are normally closed when the coil of that relay is not energized.
The collector of the transistor 11 is connected to the DC positive voltage present at the cathode of the ZENER diode Z of the DC power supply circuit through a resistor 17 while its emitter is connected to the ground and the base of a transistor 14 through resistors 18 and 19, respectively.
When the transistor 11 is conducting, the base of the transistor 14 is supplied with a current which energizes the coil 15 of an electromagnetic relay Al through the collector-emitter conductive path of the transistor 14. A
protecting diode 20 is mounted in parallel to this coil 15.
The coil 16 of the electromagnetic relay A2 has one of its terminal connected to the DC positive voltage generated by the D.C. power supply. It can be energized through a transistor 23 or a manual switch 27 bokh mounted 3~
between the other termlnal of the coil 16 and the ground of the DC power supply which is also the ground of the circuit of the switching apparatusO The switch 27 is de-pressed when a user wants to initiate operation of the switching apparatus inherent to the energization of the relay A2 as will be explained in details hereinafter. The switch 27 energizes the coil 16 through a resistor 25 and a capacitor 26 connected in parallel and disposed between the switch 27 and said other terminal of the coil 16 having a protecting diode 28 mounted in parellel thereto.
The conduction of the collector-emitter path of the transis-tor 23 is controlled through its base by the action of a network comprising a resistor 24, a capacitor 22, and a first pair of N.C. contacts Al of the relay Al, intercon-necte~ as s~own on Figure 1 an~ mounted between the base of the transistor 23 and the DC positive supply voltage. A
first pair of N.O. contacts Al of the relay Al and a resistor 21 are provided for dlscharging the capacitor 22 when the relay Al is energized.
When the switch S is in the position auto and the subscriber's line 10 is in a normal condition, corre-sponding to a condition present on the line when a telephone receiver connected thereto is in an on hook position, a capacitor 29 stores energy from a DC voltage of 4B V avail-able on the line 10 through a high resistance path formed by a diode 31 and a resistor 30. The diode 31 prevents the voltage through the capacitor 29 from affecting signals on the line 10. After five time constants which are determined by the values of the resistor 30 and the capacitor 29, the capacitor 29 is completely charged to the same voltage level of 48 V as the line 10, and when the position of the switch S is subsequently selected to TIMER, the energy stored in the capacitor 29 is sufficient to keep the coil 15 of the relay ~1 energized during a period of time determined by the 6~
RC time constant of the capacitor 29 and the input imped-ance of the network involving the transistors 11 and 14, by supplying a base current to the transistors 11 and 14 through the switch S, the contacts A2 ~ the diode 13 and the resistor 12. The value of the capacitor 29 is selected for this purpose.
This time-operation of the swi-tching apparatus 160 may be used for timel.y energizing for example a TV
receiver 161, ~s shown on Figure 3, through an ~.c. outlet 32 having, as illustrated on Figure 1, a first contact connected to the plug P through the switch S and a second contact connected to the plug P through the fuse F, a switch 33 having its position appropriately selected, and a second pair of N.O. contacts Al of the relay Al. When the capacitor 29 is discharged, the coil 15 is de-energized, thereby opening contacts Al . This opening consequently de-energizes the TV receive3 supplied through the outlet 32.
As can be seen on Figure 1, relays Al and A2 are interconnected in a time delay flip flop configuration When the switch S is in its position aAUTO, this configura-tion senses conditions present on the subscriber's line 10 such as a ringing voltage, dial pulse trains, an on hook or off hook conditions of a telephone receiver connected to this line 10, etc... .
The following explanations will now be given, assuming that the switch S is in its AUTO positionO
As mentioned above, when the subscriber's tele-phone line 10 is in a normal idle condition, which condition corresponds to an on hook position of a telephone receiver connected to the line without no incomi.ng ringing voltage, a permanent 4~ V DC voltage is available rom -the line 10.
This 48 V DC voltage supplies a base current to the tran-sistors 11 and 14 through the N.C. contacts A2 / the diode 13 and the resistor 12~ thereby keeping the relay Al ener-3~
gized and the relay A2 de-energized through the N.C.
contacts A12-When other conditions occurs on the line 10 suchas a ri.nging voltage, a dial pulse train or a 6 Volts DC
voltage corresponding to an of-f hook position of -the telephone receiver, the relays Al and A2 carry acknowledg-ment of such conditions. More particularly, ~he coil of the relay A1 is instantaneously de-activated due to an at least momentarily decrease of the voltage on the line 10 under a certain level due to the network involving resistors 12, 18 and 19 and transis-tors 11 and 14. The N.C. contacts A12 are then closed, thereby energizing ~he coil 16 of relay A2 by supplying a base current to the transistor 23 through the capacitor 22 and the resistor 24.
As illustrated on Figure 4, the AcC. outlet 32 of Figure 1 may be used to supply, for example, a radio receiver 151 through the N.O. contacts A13 by appropriately selecting the position of the switch 33 as long as a perma-- nent 48 V DC voltage is present on the line 10. On the occurrence of a ringing vo'tage on the line 10, the de-energization of the coil 15 of the relay Al opens the N.O.
contacts A13 for automatically disconnecting the radio receiver 151 upon receival of a call and for also automati-cally re-connecting this radio receiver after the receiver returns in its normal on hook position and the permanent 48 V voltage is re-established on the line.
The opening of the N.C. contacts A2 as the relay A2 is energized, prevents the relay Al from following the ringing voltage occurring on the line or possibly a dial pulse train transmitted on the line 10 by a receiver con-nected to this line.
The relay A2 is time delay operated since the base current of the transistor 23 energ.izing the coil 16 of this relay, can flow through the capacitor 22 only until ~:0~3~
the latter is completely charged. Therefore, during a relatively long off hook condition of a receiver connect-ed to the line 10, i.e. with a 6 ~olts DC voltage present on the line lO, both relays Al and A2 becomes deactivated.
It should be noted that with the system of Figure 4, as the relay Al is also de-energized in response to an off hook position of a telephone receiver connected to the line 10, the radio receiver 151 is switched off when this receiver is in an off hook position and switched on when this receiver is in an on hook position.
As already stated above, every time the coil 15 of the relay Al is energized, the N.O. contacts All are closed thereby discharging in a closed loop the capacitor 22 through the resistor 21 as the N.C. contacts A12 are open at that time.
The A.C. outlet 32 may also be used to supply any o-ther external systeml when the coil 15 of the relay Al is de-energized in response to the above-defined conditions on the line lO, through a second pair of N~C. contacts Al of the relay Al, by appropriately selecting the position of the switch 33.
The switching apparatus of the invention comprises a second section 34 shown on Fi~ure 1 for displaying an actual operation thereof. This second section comprises two light emitting diodes (LED) 39 and 47 which monitor the switching device operation.
More particularly, these two LEDIs display the positions of the contacts of the relays Al and A2 as well as the position of the contacts of a relay A4, and thereby they display the operation of the switching apparatus. The operation of the relay A4 will be defined in detail herein-after.
If the relay Al is energized and therefore a third pair of N.O. contacts Al of this relay are closed, ~L2~3~
the LED 39 is activated through a resistor 38 for dis-playing the operation of this relay. A protecting resistor 37 is moun-ted in paralle] with this LE~ 39.
In the occurrence on the telephone line 10 of a ringing voltage or an ~off hook position of a telephone receiver connected thereto, the coil 15 of he relay Al is de-activated and therefore a third pair of N.C. contac~s Al of this relay are closed for energi~ing the LED 4 7 through a resistor 48 for displaying the operation of the switching apparatus. Another protecting resistor 26 is also mounted in parallel to the LED 47.
After the subscriber's line 10 returns to its normal idle condition, i.e. to a DC voltage of ~8 V., the LED 39 is energized as the N.O. contacts Al closes due to the energization of the relay Al. The LED 47 also stays lighted due to the 1ip-flop action of transistors 42 and 43. The circuit including these transistors 42 and 43 also includes resistors 44, 45 and 49 interconnected as shown on Figure 1, as well as a switch 41 acting as a reset switch i~e. when the switch 41 is depressed, the LED 4 7~ is switched off. This LED 47 stays activated for the purpose of memorization.
When the relay A4 is energized, a first pair of N.O. contacts A~l of this relay is closed and N.O. contacts ~5 Al are open as the relay Al is at that time de-energized as will be seen hereinbelow. This position of the contacts A4 and Al allows the network formed by an unijonction transistor 40, a resistor 36 and a capacitor 35 to produce an intermittent lighting of the LED 39 to indicate the energization of the relay A4 and therefore the operation of the switching apparatus.
A third section 51 of the switching device shown on Figure 1 comprises an incoming and an outgoing paths for the audio or information signals both connected to the :~L2~16 i63~
telephone line lO throuyh the switch S.
The incoming path comprises two possible paths, a first path through a first pair of N.O. contacts A2 oE
the relay A2, a DC coupling capacitor 58 a resistor 57, a potentiometer 53 and an output jack connection Jl, and a second path through a second pair of N.~. contacts A2 of the relay A2, a fourth pair of N.C. contacts A18 of the relay Al, a DC coupling capacitor 54, the potentiometer 53 and the output jac~c Jl.
The audio signals are normally routed across the second path of the incoming path while the capacitor 58, the resistor 57 and the potentiometer 53 of its first path form a high impedance circuit for routing an incorning ringing voltage from the telephone line 10, as the relay A2 is energized for closing its contacts A2 upon occurrence of such a ringing voltage.
Referring now to Figure 6 of the drawings, a radio receiver 163 and a tape recorder 164~both supplied throuyh the N.C. contacts A14, the switch 33 and the A.C. outlet 32 and having their audio inputs both connected to the jack connection Jl of the switching apparatus 160, can be used for amplifying and recording a telephone conversation between a telephone receiver connected to the line lO and another remote telephone receiver, as well as for amplifying or recording any other audio signals from the line lO.
Of course, the switching apparatus 160 may also be used for visualizing signals present on the line lO on the screen of a cathode ray tube oscilloscope. In that case the signal input of the oscilloscope is connected to the jack connection Jl, as shown on Figure 8.
The outgoing path of the section 51 is formed by a second jack connection J2, a DC coupling capacitor 55 and a second pair oE N.O. contacts A4 of the relay A~. A re~
sistor 56 forming part of another section 52 of the switching 3~
apparatus has one of its terminals connected between the capacitor 55 and ~che contac~s A4 while its other t~rminal is yrounded. This resistor 56 is provided for simula-ting a condition on the telephone line, which condition corresponds to a condition present on the line 10 when a receiver con-nected thereto is in an off hook position, for establishing a ~oop in the telephonic network with a remote telephone receiver upon receipt of a call or ringing voltage therefrom.
The net~rk includin~ the jack J2, the capacitor 55 and the N.O. contacts A4 forms a path for transmittiny audio signals or other information signals to the telephone line 10 during the relay A4 of the switching apparatus is energized and therefore when this network and the simulating resistor 5b are connected to the line through the N.O. con-tacts A43-As above mentioned, the switching apparatus according to the present invention may include a fourth sec-tion 52 shown in Figure 1~
The circuit of the section 52 comprises the coils 84 and 85 of an electromagnetic relay A3 and the electro-magnetic relay A4, respectively, which relays are respec-tively responsible of the disconnection and the connection of the resistor 56 to the line 10 and at the same time of the outgoing transmission path through contacts A~ .
As set forth hereinabove, when an incoming ringing voltage is present on the telephone line, the relay Al becomes de-energized while the relay A2 becomes energized for a period of time determined by the capacitor 22 and the re-sistor 24 of Figure 1. A second pair of N.O. contacts A23 of the relay A2 are therefore closed upon energization of this relay.
An incoming ringing voltage from the line 10 stores a DC voltage across a capac.itor 64, through a resi.stor 62 by energizing the relay A2 which closes its N.O. contacts A23.
- 12 ~
~QI~;~i3~
The resistor 62 in combination with a resistor 65 fixes the maximum D.C. voltage level thro~gh the capacltor 64.
This maximum voltage is modified by a low value resistor 66 upon energization of the relay A~,which closes its third pair of N.O. contacts A4 ~during the time the N.O. contacts A2 remains closed As shown on Figure l, the voltage across the capacitor 64 supplies a current to the base of the transis-tor 77 through a network comprising in series a diode 6~, a potentiometer 69, a resistor 70, and a resistor 78 mounted in parallel with a first pair of N.C. contacts A42 of the relay A4-The current routed from the capacitor 64 to the base of the transistor 77 is transformed into a correspond-ing voltage due to the integrating action of a capacitor 72 mounted in parallel with a resistor 73 between the ground and the base of this transistor 77.
The time required for charging the capacitor 64 as well as the nature of the base network of the transistor 77 determines the time at which the ringing voltage from the line lO must be generated before the coil 85 of the relay A4 is energized through the transistor 77 for connecting the simulating resistor 56 to the line lO and thereby establish-ing the above defined loop. The coil 85 of the relay A4 has a protecting diode 82 mounted in parallel thereto. The resistance value of the potentiometer 69 may be varied to adjust the time required by the ringing voltage before ener-gization of the relay ~4, or before establishment of the loop by connection of the resistor 56 to the line lO.
As soon as the voltage across the capacitor 72 is equal to the bias voltage required by the base-emitter of the transistor 77 for making conductive its collector-emitter path, the relay A~ is energized.
As illus-trated on Figure l, the fourth section 52 6~7 also includes a transistor 91 through which the coil 84 of the relay A3 is energized or de-activated. This coil 84 is energized through a circuit formed by the collector-emitter conductive path of the transistor 91 and the three diodes 60, 61 and 86 serially connected as shown on Figure 1. A
protective diode 87 is mounted in parallel with the coil 84.
The conduction of this transistor 91 is controlled through its base by the voltage present at a point N through a net-wor~ formed by a diode 88, a resistor 89, a potentiometer 90 and a capacitor 92. The coil 84 can also be energized t}lrough a manual switch 83 mounted as shown in the drawings.
Upon energization of the coil 85 of the relay A4 through the collector-emitter conductive path of the tran-sistor 77 and diodes 74 to 76, the N.O. contacts A4 are closed and a current from the line 10 flows through the resistor 56 for simulating, as mentioned above, an off hook condition of a telephone receiver connected to this line 10 by establishing the loop. The value of the resistor 56 is selected to establish the nominal aoff hook current of a telephone receiver whan it loads the telephone line 10.
The coil 84 of the relay A3 becomes activated as the voltage present across the resistor 56 or on the line 10 supplies a base current to the transistor 91 through the diode 88, the resistor 83 and the potentiometer 90. When the relay A~ is energized and the relay A2 is not energized therefore having its NØ contacts A2 open the capacitor 64 is dis-charged through the low valve resistor 66 and the third pair of N.O. contacts A~ of the relay A4 which are closed.
When the N.O. contacts A~ are closed upon energization of the relay A4, the relay A4 remains energized as the tran-sistor 77 receives a base current through a capacitor 80, a resistor 79 and a first pair of N.O. con-tacts A31 of the relay A3 which are closed when the relay A3 is energized. The capacitor 80 and the resistor 3~
79 automatically generate a 2 minutes simulation of an off hook condition by the resistor 56 as the relay A~ is time-deactivated by this resis-tor 79 and the capacitor 80 A resistor 81 in combination with a second pair of N.C. contacts A4 oE the relay A4 or a resistor 59 in combination with a switch Sw both form a current discharge path for the capacitor 30.
The function of the N.O. contacts A3 at the base of the transistor 77 is exclusively to de-energi~e the relay A4 in response to any release sig`nal from the line 10 which is detected by the circuit associated to the relay A3 and connected to the line 10. This release signal is a signal having a lower value than about 6 V. The relay A3 together with its associated circuit are therefore sensitive to changes in the impedance of the line 10 through the resistor 56, i.e. in the voltage level present across this resistor or present on the line at the subscriber's location. The transistor 91 is not affected by any audio or information signals transmitted to or received from the line 10 due to the action of the capacitor 92. The relay A4 is de-energized and therefor the connection of the resistor 56 to the line 10 is released in response to such a release>~ signal from the line 10 which is acknowledged by the transistor 91 which de-energizes the coil 84 of the relay A3 and thereby the coil 85 of the relay A4 through the N.O. contacts A3 of the relay A3. The potentiometer 90 is adjusted for matching the imped-ance of its associate circuit with the impedance of the telephone line 10.
The simulation of the off-hook condition of a telephone receiver connected to the line 10 is possible in both normal (NOR) or expand ~EXP) position of the switch Sw.
With the switch Sw in its normal position NOR, the operation of the switching apparatus of the invention is as described above. Conse~uently, -the switch Sw is placed 63~
at its position NOR if a rel.atively short time of operation is needed. In this case, the switching apparatus simulates during a prede-termined period of time the off-hook>~ condi-tion.
With the switch Sw in its position NOR, the switching apparatus 160 of the present invention may be used for automatically transmit-ting audio or information signals from a tape recorder 162 to the telephone l.ine 10 through the connection J2 and the ou-tgoing path of the sec-tion 51 upon receipt of a telephone ringing voltage as diagrammatically shown on Figure 5.
In this case, the ~.C. cord of the tape recorder is connected to the AC outlet 32 supplying electrical power through W.C. contacts Al by appropriately selecting the position of the switch 33. As described above, after the reception a telephone ringing voltage from the line 10, the relay Al is de-energized and the relay A~ is energized there-by closing contacts Al and A4 for allowing the above-mentioned tranmi.ssion.
With the switch Sw in its position EXP, the opera-tion of the switching device is -the same as in its position NOR except that other contacts Sw of this Switch Sw are closed thereby supplying a base current to the transistor 77 through the resistors 59 and 79, and the N.O.
contacts A3 when the relay A3 is energized. These contacts Sw also supply power to a fifth .section of the switching apparatus through a point WO This fiEth section is designed for expanding the possibilities of the switching apparatus.
This fi:Eth section which is illustrated on Figure
2, co~prises a light emitting diode (LED) 102 activated through a resistor 101 when the contacts Sw are closed for indicating that the fifth section of the switching apparatus is switched on. The remaining circuit of this fifth section is not energized until the relay A4 is activated and its i63~
third pair of N.C. contacts A~ are opened for releasing the ground eonnection at the base of a transistor 98 supplied with a base current through a resistor 107. The D.C. voltage from the contacts Sw is then stepped down to an appropria~e level by a series vol-tage regulator compris-ing a transistor 99, a pair of resistors 108 and 109, a capacitor 111, and a ZENER diode 110. A by-pass voltage regulator involving a transistor 93, resistors 94 and 103, a ZEN~:R diode 95 and a capacitor 96 also supply a part of this fifth section when the transistor 93 is switched on.
These two regulators can supply a circuit 130 through diodes 100 and 97 respeetively.
The eireuit ineluding the eomparator 118 is a time-dependent network preventing unwanted signals from triggering the fifth seetion of the switehing apparatus.
In normal operationt the output of the comparator 118 is always at a ~low logic level. During each incoming ringing voltagel the relay A2 is energized and closes its third pair of N.O. contaets A2 for diseharging a eapaeitor 116 through a resistor 117. After the timed energization of the A2 i5 terminat2d, the capacitor il6 is charged at a very low rate through a resistor 112. The voltage aeross the capacitor is transmitted to a first input of the comparator 118 through a resistor 115. When the voltage at this first input of the comparator 118 supplied by the capacitor 116, reaches the voltage applied to a second input of the eomparator 118 by a potentiometer 113 through a resistor 114, the output of the eomparator 118 then beeomes high. The eoil 104 of the relay ~5 is therefore energized through the collector-emitter eonduetive path of the transistor 105 supplied with a base eurrent by the output of the eomparator 118 through a diode 120 and a resistor 119.
The eonduction of the transistor 105 also aetivates the above defined by-pass regulator by generating a base ~%G~
current for the transistor 93 through the resistor 103 for providing a separate power supply to the integrated circuit 130 through the resistor 94, the ZENER diode 95, the capaci-tor 96 and the diode 97. This separate power supply is necessary to permit the circuit 130 to stay in operation when the relay A4 is de-activated and its N.C. contacts A4 becomes closed thereby de-energizing the above-mentioned series voltage regulator and de energizing the comparator 11~ whose output stops to activate the transistor 105.
When the series voltage.regulator is in operation, resistor 125 and 1~6 transmit to an input 2 of the integrated circuit 130 a high level signal. After the output of the comparator 118 is high, the transistor 122 receives a base-current through the resistor 121 and consequently the siynal at the input 2 of the circuit 130 becomes <~low as the collector-emitter conductive path of the transistor 122 is switched on.
The circuit 130 may consists of an integrated circuit of the well-known type 555 polarized for a monostable operation by resistors 129 and 132, and capacitors 128, 131 and 134 to 138.
A manual swi.tch 133 is used for selecting, by connecting or disconnecting capacitors 13~ to 138 to the input 6 of the circuit 130, the width of the positive pulse generated at the output 3 of this circuit 130 in response to the above defined high to low level transition occurring at the input 2 of this circuit 130. This positive pulse can be tranmitted to the base of the transistor 105 through a manual switch 127, a resistor 123, and a diode 124 for energizing the relay A5 a~ter the relay A4 is de-energized and the output of the comparator 118 becomes low. The by-pass regulator and the coil 104 of the relay A5 are switched off when the output 3 of the circuit 130 becomes low, there-by switching off the fifth section of the switching apparatus.
663~
The relay A5 controls the supply of an AC outlet 50 shown in Figure 1 through its first pair of N.O. contacts A51 .
~uxiliary connections 155 as shown in Figure 1 give access to a first pair of N.C. contacts A5 and a second pair of N~O. contacts A5 of the relay A5.
The fifth section of Figure 2 also includes a circuit comprising two NAND gates 147 and 148, resistors 142, 149, 150 and 170, capacitors 145 and 146, a pote~tio -meter 144 and a transistor 143. When the series-regulator is in operation, i.e. as long as ~he relay A4 is energized and the above-defined loop is established, this circuit genera-tes and supplies through a third pair of N.O. con-tacts A5 to the test pin N of Figure 1, i.e. -to the telephone line, an acknowledgement tone frequency of lkH . of course, this generating circuit maybe or not connected to the pin N according to the user's requirements.
The fifth section of the switching apparatus is mainly useful for industrial purpose. However, it may be used for a plurality of domestic applications.
Figure 7 shows another exemple of application of the switching apparatus of the invention for controlling and/or monitoring the operation of a generator 168 through a digital selector 165 and a plurality of transducers (illustrated by the references 166 and 167 on Figure 7).
The selector 164 comprises a plurality of inputs Il to In each associated with one transducer for transmitting signals from these transducers to the telephone line through the jack J2. This selector is energized by the ~.C. outlet 50 and may receive data from the line 10 through a line 170, which data are transmitted by a modem at a remote location o~ the telephone network.
Some applications of the switching apparatus of the present invention have been defined with reference to Figure 3 to 8. Of course, a plurality of other applications ~2~ 7 are possible according to the consummer's needs.
Although the present invention has been described with reference to one preferred embodiment only, it should be noted that modifications to th:is emhodiment within the scope of the following claims are not deemed to change the nature of the present invention.
third pair of N.C. contacts A~ are opened for releasing the ground eonnection at the base of a transistor 98 supplied with a base current through a resistor 107. The D.C. voltage from the contacts Sw is then stepped down to an appropria~e level by a series vol-tage regulator compris-ing a transistor 99, a pair of resistors 108 and 109, a capacitor 111, and a ZENER diode 110. A by-pass voltage regulator involving a transistor 93, resistors 94 and 103, a ZEN~:R diode 95 and a capacitor 96 also supply a part of this fifth section when the transistor 93 is switched on.
These two regulators can supply a circuit 130 through diodes 100 and 97 respeetively.
The eireuit ineluding the eomparator 118 is a time-dependent network preventing unwanted signals from triggering the fifth seetion of the switehing apparatus.
In normal operationt the output of the comparator 118 is always at a ~low logic level. During each incoming ringing voltagel the relay A2 is energized and closes its third pair of N.O. contaets A2 for diseharging a eapaeitor 116 through a resistor 117. After the timed energization of the A2 i5 terminat2d, the capacitor il6 is charged at a very low rate through a resistor 112. The voltage aeross the capacitor is transmitted to a first input of the comparator 118 through a resistor 115. When the voltage at this first input of the comparator 118 supplied by the capacitor 116, reaches the voltage applied to a second input of the eomparator 118 by a potentiometer 113 through a resistor 114, the output of the eomparator 118 then beeomes high. The eoil 104 of the relay ~5 is therefore energized through the collector-emitter eonduetive path of the transistor 105 supplied with a base eurrent by the output of the eomparator 118 through a diode 120 and a resistor 119.
The eonduction of the transistor 105 also aetivates the above defined by-pass regulator by generating a base ~%G~
current for the transistor 93 through the resistor 103 for providing a separate power supply to the integrated circuit 130 through the resistor 94, the ZENER diode 95, the capaci-tor 96 and the diode 97. This separate power supply is necessary to permit the circuit 130 to stay in operation when the relay A4 is de-activated and its N.C. contacts A4 becomes closed thereby de-energizing the above-mentioned series voltage regulator and de energizing the comparator 11~ whose output stops to activate the transistor 105.
When the series voltage.regulator is in operation, resistor 125 and 1~6 transmit to an input 2 of the integrated circuit 130 a high level signal. After the output of the comparator 118 is high, the transistor 122 receives a base-current through the resistor 121 and consequently the siynal at the input 2 of the circuit 130 becomes <~low as the collector-emitter conductive path of the transistor 122 is switched on.
The circuit 130 may consists of an integrated circuit of the well-known type 555 polarized for a monostable operation by resistors 129 and 132, and capacitors 128, 131 and 134 to 138.
A manual swi.tch 133 is used for selecting, by connecting or disconnecting capacitors 13~ to 138 to the input 6 of the circuit 130, the width of the positive pulse generated at the output 3 of this circuit 130 in response to the above defined high to low level transition occurring at the input 2 of this circuit 130. This positive pulse can be tranmitted to the base of the transistor 105 through a manual switch 127, a resistor 123, and a diode 124 for energizing the relay A5 a~ter the relay A4 is de-energized and the output of the comparator 118 becomes low. The by-pass regulator and the coil 104 of the relay A5 are switched off when the output 3 of the circuit 130 becomes low, there-by switching off the fifth section of the switching apparatus.
663~
The relay A5 controls the supply of an AC outlet 50 shown in Figure 1 through its first pair of N.O. contacts A51 .
~uxiliary connections 155 as shown in Figure 1 give access to a first pair of N.C. contacts A5 and a second pair of N~O. contacts A5 of the relay A5.
The fifth section of Figure 2 also includes a circuit comprising two NAND gates 147 and 148, resistors 142, 149, 150 and 170, capacitors 145 and 146, a pote~tio -meter 144 and a transistor 143. When the series-regulator is in operation, i.e. as long as ~he relay A4 is energized and the above-defined loop is established, this circuit genera-tes and supplies through a third pair of N.O. con-tacts A5 to the test pin N of Figure 1, i.e. -to the telephone line, an acknowledgement tone frequency of lkH . of course, this generating circuit maybe or not connected to the pin N according to the user's requirements.
The fifth section of the switching apparatus is mainly useful for industrial purpose. However, it may be used for a plurality of domestic applications.
Figure 7 shows another exemple of application of the switching apparatus of the invention for controlling and/or monitoring the operation of a generator 168 through a digital selector 165 and a plurality of transducers (illustrated by the references 166 and 167 on Figure 7).
The selector 164 comprises a plurality of inputs Il to In each associated with one transducer for transmitting signals from these transducers to the telephone line through the jack J2. This selector is energized by the ~.C. outlet 50 and may receive data from the line 10 through a line 170, which data are transmitted by a modem at a remote location o~ the telephone network.
Some applications of the switching apparatus of the present invention have been defined with reference to Figure 3 to 8. Of course, a plurality of other applications ~2~ 7 are possible according to the consummer's needs.
Although the present invention has been described with reference to one preferred embodiment only, it should be noted that modifications to th:is emhodiment within the scope of the following claims are not deemed to change the nature of the present invention.
Claims (24)
1. A switching apparatus connectable to a subscriber's telephone line and including a plurality of connecting means for connecting at least one external, electrically operated system, said switching apparatus comprising:
first switching means including means for detect-ing conditions on the telephone line, said detecting means controlling operation of said first switching means in relation with said conditions on the line;
first supply means including first connecting means forming part of said plurality of connecting means, said first connecting means being connected to or discon-nected from an electrical power source by said first switch-ing means depending on said detected conditions;
second switching means activated by said first switching means after detection by said detecting means of a first condition amongst said conditions;
means for deactivating said second switching means upon occurrence of a release signal on the telephone line;
means for simulating a second condition amongst said conditions on the telephone line, said simulating means being interconnected with the telephone line by said second switching means when said second switching means are activated; and means for transmitting an incoming information signal from the telephone line to second connecting means forming part of said plurality of connecting means, and for transmitting an outgoing information signal from third connecting means forming part of said plurality of connect-ing means to the telephone line, said transmitting means comprising first means for transmitting the incoming infor-mation signal from the telephone line to said second con-necting means, said first transmitting means being connected to the telephone line by said first switching means after detection by the detecting means of said second condition, or disconnected from the telephone line by the first switch-ing means after detection by said detecting means of a third condition amongst said conditions, and second means for transmitting the outgoing information signal to the tele-phone line from said third connection means, said second transmitting means being connected to or disconnected from the telephone line by said second switching means when said second switching means are activated and deactivated, re-spectively, whereby, in operation, the switching apparatus connects said at least one system to, or disconnects it from the electrical power source through said first connecting means when such system is connected to said first connecting means, said switching apparatus connecting said at least one system to or disconnecting it from said telephone line through the second and/or third connecting means when such system is connected to said second and/or third connecting means.
first switching means including means for detect-ing conditions on the telephone line, said detecting means controlling operation of said first switching means in relation with said conditions on the line;
first supply means including first connecting means forming part of said plurality of connecting means, said first connecting means being connected to or discon-nected from an electrical power source by said first switch-ing means depending on said detected conditions;
second switching means activated by said first switching means after detection by said detecting means of a first condition amongst said conditions;
means for deactivating said second switching means upon occurrence of a release signal on the telephone line;
means for simulating a second condition amongst said conditions on the telephone line, said simulating means being interconnected with the telephone line by said second switching means when said second switching means are activated; and means for transmitting an incoming information signal from the telephone line to second connecting means forming part of said plurality of connecting means, and for transmitting an outgoing information signal from third connecting means forming part of said plurality of connect-ing means to the telephone line, said transmitting means comprising first means for transmitting the incoming infor-mation signal from the telephone line to said second con-necting means, said first transmitting means being connected to the telephone line by said first switching means after detection by the detecting means of said second condition, or disconnected from the telephone line by the first switch-ing means after detection by said detecting means of a third condition amongst said conditions, and second means for transmitting the outgoing information signal to the tele-phone line from said third connection means, said second transmitting means being connected to or disconnected from the telephone line by said second switching means when said second switching means are activated and deactivated, re-spectively, whereby, in operation, the switching apparatus connects said at least one system to, or disconnects it from the electrical power source through said first connecting means when such system is connected to said first connecting means, said switching apparatus connecting said at least one system to or disconnecting it from said telephone line through the second and/or third connecting means when such system is connected to said second and/or third connecting means.
2. The switching apparatus of claim 1, further comprising display means and means for energizing said dis-play means in order to display the actual state of said first and second switching means.
3. The switching apparatus of claim 1, wherein said first switching means comprise a first electromagnetic relay including a first and a second pair of contacts mounted in parallel between the electrical power source and said first connecting means of the first supply means, said first pair of contacts being closed while the second pair of con-tacts is open if the first relay is energized, whereas said first pair of contacts being open while the second pair is closed if the first relay is not energized, and wherein said first supply means further comprise a bipolar switch mounted between said first connecting means and said first and second pairs of contacts, for selecting one of these first and second pairs, said selected pair of contacts being used for connecting the power source to, or disconnecting it from said first connecting device through said bipolar switch.
4. The switching apparatus of claim 3, wherein said detecting means comprise means for energizing the first electromagnetic relay in response to the third condition amongst said conditions and for de-energizing said first relay in response to the first and second conditions.
5. The switching apparatus of claim 3, wherein the first switching means comprise a second electromagnetic relay and said detecting means comprise means for energizing this second relay is response to said first condition, the energization of said second relay disconnecting said first electromagnetic relay and activating said second switching means which are respectively disconnected and activated through a pair of contacts of the second relay.
6. The switching apparatus of claim 5, wherein the first switching means comprise means for de-energizing the second electromagnetic relay within a predetermined period of time after its energization.
7. The switching apparatus of claim 1, wherein the transmitting means further comprise a high impedance path for transmitting said first condition from the telephone line to the second connecting means, said first switching means connecting to the telephone line said high impedance path upon detection by said detecting means of said first condition or disconnecting from the telephone line said high impedance path upon detection by the detecting means of said second condition.
8. The switching apparatus of claim 1, further comprising timing means for delaying the activation of the second switching means by the first switching means for a predetermined period of time, said predetermined period of time determining the time of occurrence of the first condi-tion on the telephone line, which first condition is inter-rupted when the second switching means are activated for connecting said simulating means to the telephone line at the end of said predetermined period.
9. The switching device of claim 8, further com-prising means for adjusting said predetermined period of time.
10. The switching apparatus of claim 1, compris-ing timing means for deactivating said second switching means within a predetermined period of time after said second switching means are activated if said release signal has not occurred on the line before the end of said predetermined period of time.
11. The switching apparatus of claim 10, compris-ing means for inhibiting operation of said timing means.
12. The switching apparatus of claim 1, wherein the deactivating means are connected to the telephone line by said second switching means when these second switching means are activated, whereby said deactivating means become disconnected from the telephone line when these deactivating means deenergize the second switching means.
13. The switching apparatus of claim 1, further comprising timing means including means for storing elec-trical energy from the telephone line and a switch for dis-connecting the telephone line from said switching apparatus and for supplying this stored electrical energy to the first switching means to keep said electrical power source connected to said first connecting means until said stored electrical energy is consumed.
14. The switching apparatus of claim 1, further comprising third switching means and second supply means including fourth connecting means forming part of said plurality of connecting means, said third switching means connecting to or disconnecting from the electrical power source said fourth connecting means, said apparatus connect-ing said at least one system to, or disconnecting it from the electrical power source through this fourth connecting means when such a system is connected to this fourth connect-ing means.
15. The switching apparatus of claim 14, compris-ing first timing means for activating said third switching means within a first predetermined period of time after said second switching means are activated for connecting the power source to the fourth connecting means until said second switching means are deactivated.
16. The switching apparatus of claim 15, further comprising second timing means, activated by the first timing means at the same time said third switching means are acti-vated by these first timing means, in order to activate said third switching means for connecting the power source to the fourth connecting means during a second predetermined period of time whenever said second switching means are activated or not, and wherein said second timing means comprises means for adjusting said second predetermined period of time.
17. The switching apparatus of claim 16, compris-ing a first direct current supply activated by the second switching means, the first timing means being energized by the second switching means through said first direct current supply, said first and second timing means being supplied by said first direct current supply until the second switch-ing means are deactivated, the switching apparatus also comprising a second direct current supply activated by the second timing means for continuing to supply said second timing means after said second switching means are deactivated until said second predetermined period is terminated.
18. The switching apparatus of claim 17, compris-ing means for generating an acknowledgment signal during the time, the first direct current supply is activated by said second switching means, said acknowledgment signal being transmitted to the telephone line through the second switch-ing means.
19. The switching apparatus of claim 14, wherein the third switching means comprise an electromagnetic relay including a plurality of pairs of contacts, and wherein at least two of said connecting means provide external connec-tions to at least one said pairs of contacts of the electro-magnetic relay.
20. The switching apparatus of claim 1, wherein said first condition is a ringing voltage, said second condition is a condition present on the line when a tele-phone receiver connected thereto is in a off-hook position, the remaining conditons also comprising a dial pulse train and a condition present on the line when the receiver is in an on-hook position.
21. The switching apparatus of claim 5, wherein the first switching means further comprises means for manually energizing the second electromagnetic relay.
22. The switching apparatus of claim 1, compris-ing means for manually energizing said deactivating means in order to activate said second switching means.
23. The switching apparatus of claim 14, com-prising timing means activated by said second switching means in order to energize said third switching means for connecting the electrical power source to the fourth con-necting means during a predetermined period of time whenever said second switching means are activated or not.
24. The switching apparatus of claim 23, wherein said timing means comprise means for adjusting said pre-determined period of time.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000431663A CA1206637A (en) | 1983-06-30 | 1983-06-30 | Switching device connectable to a subscriber's telephone line |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000431663A CA1206637A (en) | 1983-06-30 | 1983-06-30 | Switching device connectable to a subscriber's telephone line |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1206637A true CA1206637A (en) | 1986-06-24 |
Family
ID=4125600
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000431663A Expired CA1206637A (en) | 1983-06-30 | 1983-06-30 | Switching device connectable to a subscriber's telephone line |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1206637A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2687264A1 (en) * | 1992-02-10 | 1993-08-13 | Champeil Franck | Automatic device for recording a telephone communication with amplified listening |
| US5379341A (en) * | 1993-06-16 | 1995-01-03 | Odessa Engineering, Inc. | Device for remotely resetting electronic appliances in response to telephone rings |
| US5548635A (en) * | 1994-01-21 | 1996-08-20 | Sasktel | System for controlling equipment within a telephone subscriber's premises using DTMF telephone tones |
| US5969749A (en) * | 1994-11-04 | 1999-10-19 | Canon Kabushiki Kaisha | Apparatus and method for suspending a reproduction operation reproducing image information when the arrival of a call from a communication line is detected |
-
1983
- 1983-06-30 CA CA000431663A patent/CA1206637A/en not_active Expired
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2687264A1 (en) * | 1992-02-10 | 1993-08-13 | Champeil Franck | Automatic device for recording a telephone communication with amplified listening |
| US5379341A (en) * | 1993-06-16 | 1995-01-03 | Odessa Engineering, Inc. | Device for remotely resetting electronic appliances in response to telephone rings |
| US5548635A (en) * | 1994-01-21 | 1996-08-20 | Sasktel | System for controlling equipment within a telephone subscriber's premises using DTMF telephone tones |
| US5969749A (en) * | 1994-11-04 | 1999-10-19 | Canon Kabushiki Kaisha | Apparatus and method for suspending a reproduction operation reproducing image information when the arrival of a call from a communication line is detected |
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