JPH01314056A - Annunciator for telephone line broken state - Google Patents

Abstract

PURPOSE:To output an alarm immediately when an affair takes place that a burglar invades inside a house after its telephone line is cut off by monitoring a voltage of the telephone line and annunciating it as a broken wire due to intentional telephone line cut-off if the said voltage is within a range of a prescribed voltage. CONSTITUTION:A telephone line open wire annunciator 1 is provided with a monitor section 10, an annunciation section 20 and a rosette 30 and located between a telephone set 3 and an exchange 2 of a telephone station via telephone lines L1, L2. Then the monitor section 10 monitors all voltages of idle state and talking state of the telephone line or the like and outputs an ON signal to the annunciation section 20 when the voltage is an abnormal voltage due to the broken telephone line within a prescribed voltage range. The annunciation section 20 annunciate it as a broken wire by buzzing with the output of the monitor section 10. Then even if one wire of the telephone line only is cut off by a pair of ceramic-made scissors or the like, it is outputted as an alarm immediately as the broken wire.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a telephone line disconnection notification device for monitoring and notifying a disconnection of a telephone line.

[Prior Art] Conventionally, there has been no device that monitors and outputs a warning to telephone line subscribers for disconnections caused by disconnection of the telephone line from a central office exchange to a telephone set.

[Problem to be solved by the invention] For this reason, even if the telephone line is disconnected, there is no way to immediately know that it has been disconnected. It was enough to notice that something was wrong. Moreover, it was unclear whether it was a problem with the phone or a break in the telephone line.

In addition, in recent years, there have been many incidents in which the telephone line is cut off and the thief enters the house after breaking into the house.

The present invention has been made in view of solving the above problems, and an object of the present invention is to provide a telephone line disconnection notification device that immediately notifies a disconnection of a telephone line as a telephone line disconnection.

[Means for Solving the Problems] In order to achieve the above object, a telephone line disconnection notification device of the present invention has the following configuration. That is, it includes a monitoring means for monitoring the voltage value of the connected telephone line, and a notifying means for determining that the telephone line is disconnected when the monitored voltage value of the monitoring means is detected to be within a predetermined voltage range.

[Function] In the above configuration, the voltage value of the connected telephone line is monitored, and if the voltage value is within a predetermined voltage value range, it is operated to notify that the line is disconnected.

[Embodiment] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[Description of Configuration (FIG. 1)] FIG. 1 is a block diagram of a telephone line disconnection notification device 1 of this embodiment, which includes a monitoring section 10, a notification section 20, and a rosette 30 as shown. A telephone line is located between the exchange 2 of the telephone office and the telephone 3 via the telephone lines Ll and L2, and monitors disconnections due to disconnection of the telephone lines LL and L2 and outputs an alarm, as will be described later. This is a disconnection notification device l.

[Description of operation (FIGS. 2 and 3)] Next, an example of the monitoring unit 10 in this embodiment will be described below with reference to the window comparator circuit in FIG. 2 and the operational relationship diagram in FIG. Explain.

First, the monitoring unit 1O of this embodiment monitors all voltage values such as the idle state and call status of the telephone line, and when the voltage value is an abnormal voltage value due to a disconnection of the telephone line, the notification unit 20 is turned on. Output a signal. The notification unit 20 then sounds a buzzer using the output of the monitoring unit 10 to notify the user of the disconnection.

Next, an overview of the operation of the voltage comparator will be explained, focusing only on the comparator 16 of the window comparator circuit shown in FIG.

As an input to the comparator 16, if the voltage value of the telephone line is Vin, the voltage value set by the resistor 12 is Vref, and the output is Vout, then Vout is on when Vin<Vref, and Vout is on when Vin>Vref. outputs off, and when Vout turns on, the relay (Ry) is driven.

A window comparator circuit shown in FIG. 2 is a circuit in which the operating point can be arbitrarily set by combining it with an arithmetic circuit.

In this circuit, FIG. 3 is a diagram showing the relationship between the voltage values corresponding to each use state of the telephone line and the output of the monitoring section 10, and the operation will be described below with reference to FIG.

It is known that the voltage value of a normal telephone line in an idle state is 48V, and that it decreases to about 4V to 20V in a call state depending on the impedance of the telephone. Therefore, the abnormal voltage value in this example is 3V or less and 21V~
There are two ranges for each 47V. Then, a second
This is done using the resistors 12 and 14 shown in the figure, and the output signal is turned on by the resistor 12 and turned off by the resistor 14.

As shown in FIG. 3, if the telephone line is idle, the voltage value is 48V, and the output signal at that time is off.

Then, when the phone enters the call state due to an incoming call,
The voltage value changes from 6 to 20V, but the output signal remains off.

However, if Ll and L2 of the telephone line are cut at the same time with metal scissors, etc., the voltage value will immediately drop below 3V due to the short circuit of the telephone line, and the output signal for that voltage value will be:
Turns on. However, if either the telephone line Ll or L2 is disconnected, it takes about 20 seconds for the voltage value to reach Ov due to discharge of the capacitor inside the low set 30 and the telephone. For this purpose, for example, if the telephone line is idle, the voltage value gradually decreases from 48V to 47V, and when it reaches 46V, the output signal is turned on.

Next, the notification section 20 which inputs the output signal from the monitoring section 10 and notifies the ON signal thereof uses a buzzer in this embodiment, but may also use a notification device such as a speaker.

Further, the monitoring unit 10 of this embodiment monitors the voltage value of the telephone line, and includes an output means for outputting an AC signal to the connected telephone line, a monitoring means for monitoring the received AC signal of the telephone line,
If the monitored AC signal of the monitoring unit is outside the range of the predetermined AC signal, the telephone line is disconnected and a notification unit that notifies the user to that effect is provided. AC signal) and a bandpass filter (B.

P, F) and level meters (L, M)) may be used to monitor the AC signal of the telephone line and output a disconnection.

With the above configuration, it is possible to output an AC signal to the telephone line, monitor the AC signal on the telephone line, and immediately notify that the telephone line is disconnected if it is out of a predetermined range.

According to this embodiment, even if only one side of the telephone line is cut with ceramic scissors or the like, it is possible to immediately output a warning as a disconnection.

[Effects of the Invention] As described above, according to the present invention, the voltage value of the telephone line can be monitored, and if the voltage value is within a predetermined voltage value range, it is possible to immediately notify that the telephone line is disconnected due to disconnection or the like. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a telephone line disconnection notification device according to an embodiment of the present invention, FIG. 2 is a circuit diagram of the monitoring unit 10 of FIG. 1, and FIG. 3 is a diagram explaining the operational relationship of FIG. 2. , FIG. 4 is a block diagram of another configuration of the monitoring unit 10. In the figure, l...Telephone line disconnection alarm device, 2... Switchboard,
3...Telephone, 10...Monitoring section, 20...Notification section, 30...Rosette. Patent applicant: Gunma Sogo Guard System Co., Ltd. (and 1 other
Figure 1 IQ i! Fan v1 Figure 3 +0-

Claims (1)

[Claims] A telephone line comprising: a monitoring means for monitoring the voltage value of a connected telephone line; and a notification means for determining that the telephone line is disconnected when the monitoring voltage value of the monitoring means is within a predetermined voltage range. Disconnection alarm device.