TW201605168A - Switch device and load control system including the same - Google Patents

Abstract

A problem to be solved of the present invention is that a switch between ON and OFF of a switch element is less apt to be caused by a back electromotive force occurring in a load when power supply to the load is broken. In a switch device (1) of the present invention, a contact (111) of a relay (11) is inserted in and electrically connected to an electric path that connects an AC power source (200) to an air fan load (400). A bidirectional thyristor (12) is inserted in and electrically connected to an electric path that connects the AC power source (200) to a lighting load (300). A surge absorber circuit (60) for reducing the surge voltage applied to the bidirectional thyristor (12) is connected between the AC power source (200) and the lighting load (300) in parallel with the bidirectional thyristor (12).

Description

Switch device and load control system therewith

The present invention relates to a switching device, and more particularly to a switching device for switching between a state in which electric power is supplied from an AC power source to a load and a state in which supply of electric power is interrupted, and the present invention also relates to a load having the switching device Control System.

Conventionally, an automatic switch having a heat ray sensor has been proposed, the heat ray sensor including a heat ray sensor for detecting heat rays radiated from a human body (for example, see Japan) Published Patent Publication No. 2005-183319 A, hereinafter referred to as Document 1). The automatic open relationship with the heat ray sensor is used to switch between a state in which the power system is supplied to the load based on the output of the heat ray sensor and a state in which the power supply to the load is stopped. The automatic switch with a heat ray sensor is connected to a fan load and a lighting load (as a load). The automatic switch with a heat ray sensor includes a relay connected between the AC power source and the fan load, and a bidirectional thyristor connected between the AC power source and the lighting load. The automatic switch can individually turn on or off the relay and the two-way thyristor.

The fan load includes a motor to rotate the fan and has a risk of a counter electromotive force occurring in the motor when the relay is turned off to interrupt the power supply to the fan load. When the counter electromotive force occurring in the motor enters a switching circuit for switching between ON and OFF of the bidirectional thyristor (semiconductor switch), the bidirectional thyristor can be turned on for a short time. When a light-emitting diode having a higher response than an incandescent lamp is used as a lighting load, there is a risk that the two-way thyristor is turned on by the counter electromotive force occurring in the motor for a short time and the light-emitting diode is briefly illuminated.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a switching device in which a counter electromotive force occurring in a load is less likely to be connected when a power supply to a load is interrupted. Switching between on and off of a switching element between the AC power source and another load; and an object of the present invention is to further provide a load control system including the switching device.

The switching device of the present invention includes a plurality of first terminals connected to a first load, a plurality of second terminals connected to a second load, and an electrical path inserted and electrically connected to connect an AC power source to the first load a first switching element, and a second switching element inserted and electrically connected to an electrical path connecting the AC power source to the second load. The second switching element includes a semiconductor switch. A surge absorbing element for reducing a surge voltage applied to the second switching element is coupled between the AC power source and the second load and in parallel with the second switching element.

The load control system of the present invention includes a switching device, a first load coupled to the first terminal, and a second load coupled to the second terminal. The first load is an inductive load and the second load is an LED illuminator. The surge absorbing element is configured to reduce a surge voltage applied to the second switching element by a counter electromotive force occurring in the inductive load when the first switching element is turned off.

According to the present invention, it is possible to provide a switching device in which the back electromotive force occurring in the load is less likely to be connected between the AC power source and another load when the power supply to a load is interrupted. A switching element switches between on and off; and we may provide a load control system that includes the switching device.

Hereinafter, the switching device and the load control system of the present embodiment will be described with reference to the drawings. The configurations described below are merely an example of the present invention. The present invention is not limited to the following embodiments, and various modifications may be made thereto without departing from the spirit and scope of the invention.

Fig. 1 is a circuit diagram of a switching device 1 of the present embodiment.

The switching device 1 of the present embodiment includes relays 10 and 11, a bidirectional thyristor 12, a first driving circuit 20, a switching circuit 30, a signal processing unit 40, a second driving circuit 50, and a surge absorbing circuit 60 (surge absorbing element) ), human sensor 70, and power circuit 80.

The switching device 1 of the present invention includes two input terminals 91 and 92 that are connected to an AC power source 200 (e.g., a commercial AC power source). The switching device 1 further includes two load terminals 93 and 94 (second terminal) connected to the lighting load 300 as the second load, and two load terminals 95 and 96 connected to the fan load 400 as the first load. (first terminal). The input terminal 92 is electrically connected to the load terminals 93 and 95 via internal wiring of the switching device 1. For example, the lighting load 300 includes an LED illuminator that includes a light emitting diode (LED) as a light source.

The contact 101 of the electromagnetic relay 10 is connected between the input terminal 91 and the load terminal 94. The current limiting resistor R1 is connected between the load terminal 93 and the load terminal 94. In a state where the AC power source 200 is connected between the input terminals 91 and 92 and the lighting load 300 is connected between the load terminals 93 and 94, the AC power source 200 is connected to the contact 101 via a parallel circuit of the resistor R1 and the illumination load 300. Between the two ends.

A series circuit of the two-way thyristor 12 and the coil L1 is connected between the two ends of the contact 101. The bidirectional thyristor 512 on the output side of the photocoupler 51 is electrically connected between the terminal T2 of the bidirectional thyristor 12 and the gate terminal G1 via a resistor R2. A parallel circuit of the resistor R3 and the capacitor C1 is connected between the gate terminal G1 of the bidirectional thyristor 12 and the terminal T1. Here, a second switching element including the two-way thyristor 12 as a semiconductor switch is inserted in an electrical path connecting the AC power source 200 to the lighting load 300 and electrically connected to the electrical path.

The contact 111 of the electromagnetic relay 11 is connected between the input terminal 91 and the load terminal 96. In a state where the AC power source 200 is connected between the input terminals 91 and 92 and the fan load 400 is connected between the load terminals 95 and 96, the series circuit of the AC power source 200 and the fan load 400 is electrically connected at the two ends of the contact 111. between. Here, the contact 111 of the relay 11 as the first switching element is inserted in an electrical path connecting the AC power source 200 to the fan load 400 and electrically connected to the electrical path.

The rectifier DB1 formed by the diode bridge is connected between the input terminal 91 and the input terminal 92 via a series circuit of a resistor R5 and a capacitor C3.

The switch circuit 30 is connected to the output side of the rectifier DB1. The switch circuit 30 includes a resistor R6, a Zener diode ZD1 and ZD2, and a transistor 31.

A series circuit of the resistor R6 and the Zener diode ZD1 is connected between the direct current (DC) output terminals DB11 and DB12 of the rectifier DB1. The cathode of the Zener diode ZD1 is connected to the resistor R6, and the anode of the Zener diode ZD1 is connected to the DC output terminal DB12 (the ground of the circuit) on the low potential side of the rectifier DB1.

The transistor 31 is an NPN transistor. The collector of the transistor 31 is connected to the DC output terminal DB11 on the high potential side of the rectifier DB1 via the sense diode ZD2. Here, the cathode of the Zener diode ZD2 is connected to the DC output terminal DB11 on the high potential side of the rectifier DB1, and the anode of the Zener diode ZD2 is connected to the collector of the transistor 31. The base of the transistor 31 is connected to the junction between the resistor R6 and the gate diode ZD1.

For example, the smoothing capacitor C4 formed by the electrolytic capacitor is connected between the emitter of the transistor 31 and the ground of the circuit. The emitter of the transistor 31 is electrically connected to the anode of the LED (Light Emitting Diode) 511 included in the photocoupler 51 via a resistor R7. The cathode of the LED 511 is connected to the ground of the circuit via a switching element 52, such as a transistor. The control terminal of the switching element 52 is connected to the output 埠P3 of the signal processing unit 40, and the switching element 52 is turned on or off according to the voltage level of the output 埠P3.

One end of the relay coil 102 included in the relay 10 is electrically connected to the emitter of the transistor 31. The other end of the relay coil 102 is connected to the ground of the circuit via a series circuit of a resistor R10 and a switching element 21 (for example, a transistor). The diode D1 is connected in parallel to the relay coil 102. The cathode of the diode D1 is connected to the emitter of the transistor 31, and the anode of the diode D1 is connected to the resistor R10. The diode D1 is arranged for the purpose of forming a path through which a current caused by a counter electromotive force occurring in the relay coil 102 flows when the current flowing through the relay coil 102 is interrupted. The control terminal of the switching element 21 is connected to the output 埠P1 of the signal processing unit 40, and the switching element 21 is turned on or off according to the voltage level of the output 埠P1.

One end of the relay coil 112 included in the relay 11 is electrically connected to the emitter of the transistor 31. The other end of the relay coil 112 is connected to the ground of the circuit via a series circuit of a resistor R11 and a switching element 22 (e.g., a transistor). The diode D2 is connected in parallel to the relay coil 112. The cathode of the diode D2 is connected to the emitter of the transistor 31, and the anode of the diode D2 is connected to the resistor R11. The diode D2 is arranged for the purpose of forming a path through which a current caused by a counter electromotive force occurring in the relay coil 112 flows when the current flowing through the relay coil 112 is interrupted. The control terminal of the switching element 22 is connected to the output 埠P2 of the signal processing unit 40, and the switching element 22 is turned on or off according to the voltage level of the output 埠P2.

Therefore, the first driving circuit 20 is formed by the current limiting resistors R10 and R11 and the switching elements 21 and 22. The first driving circuit 20 is configured to selectively switch the contact state of the relays 10 and 11 as switching elements to a first state (ON state) and a second state (OFF state). Any one of them.

For example, the signal processing unit 40 includes a microcomputer and is configured to achieve a desired function by executing a program stored in a memory in the microcomputer.

The surge absorbing circuit 60 is formed by a series circuit (RC series circuit) of a resistor R4 and a capacitor C2. The surge absorbing circuit 60 is connected between the AC power source 200 and the illumination load 300 in parallel with the second switching element including the bidirectional thyristor 12, and has a function of reducing the surge voltage applied to the second switching element.

For example, the human sensor 70 includes a pyroelectric type infrared detecting element for detecting heat rays (infrared rays) radiated from the human body. The human sensor 70 detects whether a person exists in a detection area based on the detection result of the infrared detecting element. When the presence of a person is detected, the human sensor 70 outputs a detection signal to the signal processing unit 40.

The power circuit 80 is for reducing the AC voltage input from the AC power source 200, then converting the reduced AC voltage to a DC voltage of a desired voltage value, and supplying the operating voltage to an internal circuit (eg, the signal processing unit 40) .

The load control system including the switching device 1 of the present embodiment includes a switching device 1, a fan load 400 connected to the load terminals 95 and 96, and a lighting load 300 connected to the load terminals 93 and 94. The switching device 1 is configured to control the operating states of the lighting load 300 and the fan load 400 according to the detection signal of the human sensor 70 (as a triggering mode).

The switching device 1 of the present embodiment has the above configuration, and the operation of the switching device 1 is described later.

First, the operation of the switching device 1 when there is no person in the detection area of the human sensor 70 will be described.

When there is no person in the detection area of the human sensor 70, the signal processing unit 40 does not receive the detection signal from the human sensor 70. The signal processing unit 40 performs the following operations to turn off the lighting load 300 and stop the fan load 400.

When the human sensor 70 does not input the detection signal, the signal processing unit 40 sets all the voltage levels of the outputs 埠P1, P2, and P3 to the low level, and turns off all of the switching elements 21, 22, and 52. In this case, current does not flow through the relay coils 102 and 112, and both of the contacts 101 and 111 are in a closed state. The current also does not flow through the LED 511, and the bidirectional thyristor 512 is in a closed state such that the bidirectional thyristor 12 is in a closed state. Therefore, when there is no person in the detection area of the human sensor 70, the lighting load 300 is turned off and the fan load 400 is stopped. When all of the switching elements 21, 22, and 52 are in the off state, the base current does not flow through the transistor 31 and the transistor 31 is in the off state. During a period in which the output voltage of the rectifier DB1 is higher than the Zener voltage of the Zener diode ZD1, a current flows from the rectifier DB1 via the resistor R6 and the sense diode ZD1. Here, the second current path RT2 is formed by the resistor R6 and the sense diode ZD1, and drives the current from the AC power source 200 in the second state (in this state, the excitation current does not flow through the relay coils 102 and 112). )flow. The second current path RT2 is coupled to the resistor R6 to limit the current flowing through the second current path RT2.

Next, the operation of the switching device 1 when there is a person in the detection area of the human sensor 70 will be described.

When a person in the detection area of the human sensor 70 and the human sensor 70 input a detection signal to the signal processing unit 40, the signal processing unit 40 performs the following operations to turn on the illumination load 300 and cause the fan load 400 to perform ventilation. .

The signal processing unit 40 first switches the voltage levels of the outputs 埠P2 and P3 from a low level to a high level while maintaining the voltage level of the output 埠P1 at a low level. At this time, the switching element 21 is maintained in the off state, and the switching elements 22 and 52 are switched from the off state to the on state.

When the switching element 22 is turned on, the base current flows through the transistor 31 to switch the transistor 31 from the off state to the on state, and the capacitor C4 smoothes the ripple voltage input from the rectifier DB1. At this time, current flows from the capacitor C4 through the relay coil 112, the resistor R11, and the switching element 22 in order, so that the exciting current flows through the relay coil 112 to open the contact 111 of the relay 11. When the contact 111 is turned on, the AC power source 200 supplies AC current to the fan load 400 via the contact 111, and the fan load 400 rotates the motor to perform ventilation.

When the switching element 52 is turned on, current flows from the capacitor C4 through the resistor R7, the light emitting diode 511, and the switching element 52, and the bidirectional thyristor 512 is at the zero crossing point of the AC voltage input by the AC power source 200. Switch from off state to on state. When the two-way thyristor 512 is turned on, a voltage higher than a break over voltage is applied to the gate terminal (gate electrode) G1 of the bidirectional thyristor 12 and the bidirectional thyristor 12 is switched from the off state to the on state. . When the two-way thyristor 12 is turned on, AC power is supplied from the AC power source 200 to the lighting load 300 via the two-way thyristor 12 to turn on the lighting load 300.

Here, the lighting load 300 is a resistive load. Therefore, when the two-way thyristor 12 is turned on, a rush current flows from the AC power source 200 to the illumination load 300. When the lighting load 300 is turned on, the inrush current does not flow through the contact 101 of the relay 10, but through the bidirectional thyristor 12 as a semiconductor switch. In other words, when the lighting load 300 is turned on, an inrush current flows through the bidirectional thyristor 12 since the contact 101 is in the off state and the bidirectional thyristor 12 is turned on. Therefore, we can protect the contact 101. The fan load 400 is an inductive load, and the inrush current does not flow into the fan load 400 when the contact 111 is turned on. Therefore, the two-way thyristor is not connected in parallel to the contact 111, and the current carried to the fan load 400 is only turned on and off by the contact 111.

After a predetermined first delay period elapses from the time when the two-way thyristor 12 is switched from the off state to the on state, the signal processing unit 40 switches the voltage level of the output 埠P1 from the low level to the high level. At this time, the switching element 21 is switched from the off state to the on state to cause the exciting current to flow through the relay coil 102, so that the contact 101 is turned on. After a predetermined second delay period elapses from the time when the contact 101 is switched from the off state to the on state, the signal processing unit 40 switches the voltage level of the output 埠P3 from the high level to the low level. At this time, the switching element 52 is switched from the on state to the off state to stop the flow of current through the LED 511, so that the bidirectional thyristor 512 is turned off. When the two-way thyristor 512 is turned off, the two-way thyristor 12 is turned off and current flows from the AC power source 200 to the lighting load 300 only via the contacts 101. The first delay period only needs to be set slightly longer than the period during which the inrush current flows when the illumination load 300 is turned on, for example, about one second. The second delay period only needs to be set slightly longer than the required operation period (the time from when the relay coil 102 carries the current to the time when the contact 101 is closed), and is set to an appropriate period in accordance with the operational performance of the relay 10.

Therefore, when the human sensor 70 detects a person, the switching device 1 turns on the lighting load 300 and causes the fan load 400 to perform the ventilation. The switching device 1 turns on the illumination load 300 by switching the bidirectional thyristor 12 from the off state to the on state, so that the fusion of the contacts 101 caused by the inrush current flowing at the beginning of the opening step is suppressed. The switching device 1 causes a current to flow to the lighting load 300 via the contact 101 after the first delay period and the second delay period have elapsed since the lighting load 300 was turned on. Therefore, the heat generation of the two-way thyristor 12 caused by the current carrying or the power loss in the two-way thyristor 12 can be reduced.

In the first state in which the exciting current flows through the relay coils 102 and 112, the exciting current flows from the rectifier DB1 to the relay coils 102 and 112 via the Zener diode ZD2 and the transistor 31. In the present embodiment, the capacitor C4 is connected between the emitter of the transistor 31 and the ground of the circuit, so that the voltage input from the rectifier DB1 via the gate diode ZD2 and the transistor 31 is smoothed by the capacitor C4. To a substantially constant voltage. The voltage smoothed by the capacitor C4 is applied to the relay coils 102 and 112 so that a steady current can flow through the relay coils 102 and 112. Here, the Zener diode ZD2 and the transistor 31 constitute a first current path RT1 through which current flows from the AC power source 200 to the first drive circuit 20. Unlike the first current path RT1, the second current path RT2 includes the resistor R6 such that the impedance of the second current path RT2 is higher than the impedance of the first current path RT1. Therefore, compared with the first state in which the exciting current flows through the relay coils 102 and 112, the current flowing from the AC power source 200 to the switching circuit 30 can be suppressed in the second state in which the exciting current does not flow through the relay coils 102 and 112, And can reduce standby power.

Next, the operation of the switching device 1 when the person leaves the detection area of the human sensor 70 in a state where the lighting load 300 is turned on and the fan load 400 is performing the ventilation is described.

When all the person leaves the detection area of the human sensor 70, the input of the detection signal from the human sensor 70 to the signal processing unit 40 is stopped. After a predetermined operation holding period elapses from the time when the input of the detection signal is stopped, the signal processing unit 40 performs the following operations to turn off the lighting load 300 and stop the fan load 400.

After the operation holding period elapses from the time when the input of the detection signal from the human sensor 70 is stopped, the signal processing unit 40 switches the voltage levels of the outputs 埠P1 and P2 from the high level to the low level. The signal processing unit 40 maintains the voltage level of the output 埠P3 at a low level. In this case, current does not flow through the relay coils 102 and 112, the contacts 101 and 111 are switched from the on state to the off state, the illumination load 300 is turned off, and the ventilation by the fan load 400 is stopped.

Here, the fan load 400 is an inductive load such that a counter-electromotive force that is several times larger than the rated voltage occurs in the fan load 400 when the power supply to the fan load 400 is interrupted.

When the switching device 1 does not include the surge absorbing circuit 60, and the stray capacitance is generated between the wires connected to the load terminal 94 and the wires connected to the load terminal 95 (because the wires are in proximity to each other), the fan load is applied. The counter electromotive force occurring in 400 can enter the optical coupler 51. When the counter electromotive force that has occurred in the fan load 400 enters the photocoupler 51 and a voltage higher than the on-voltage is applied to the bidirectional thyristor 512, the bidirectional thyristor 512 and the bidirectional thyristor 12 are turned on for a short time. The lighting load 300 includes an LED (as a light source) that has a higher responsiveness to the blazing lamp, such that the lighting load 300 can be briefly turned on by the short-circuiting of the bi-directional thyristor 512 and the bi-directional thyristor 12 . When the withstand voltage of the bidirectional thyristor 12 is lower than the withstand voltage of the bidirectional thyristor 512 of the optocoupler 51, the reversal occurs in the fan load 400 when the bidirectional thyristor 12 is first turned off by the contact 111 before the bidirectional thyristor 512 The electromotive force is turned on.

In the switching device 1 of the present embodiment, the surge absorbing circuit 60 formed by the series circuit of the resistor R4 and the capacitor C2 is connected in parallel to the bidirectional thyristor 12. In other words, the surge absorbing circuit 60 is connected in parallel to the series circuit of the resistor R2, the bidirectional thyristor 512, and the resistor R3. Therefore, even if a counter electromotive force occurs in the fan load 400 when the contact 111 is closed, the rise in voltage becomes gentle, and the surge voltage applied to the second switching element including the bidirectional thyristor 12 is transmitted through Resistor R4 reduces capacitor C2 by charging it. Therefore, the counter electromotive force occurring in the fan load 400 is less likely to cause the conduction of the bidirectional thyristor 512 and the bidirectional thyristor 12, and is less likely to cause the illumination load 300 to be briefly illuminated. The surge absorbing circuit 60 is not limited to the RC series circuit of the resistor R4 and the capacitor C4. The surge absorbing circuit 60 can be other circuit configurations or varistors.

As described above, the switching device 1 of the present embodiment includes a first terminal (load terminals 95 and 96) connected to the first load (fan load 400), and a second terminal (lighting load 300) connected to the second load (lighting load 300) Terminal (load terminals 93 and 94). The switching device 1 includes a first switching element (contact 111 of the relay 11) and a second switching element, wherein the first switching element is inserted in an electrical path connecting the AC power source 200 to the first load and electrically connected to the An electrical path, and the second switching element, are inserted in an electrical path connecting the AC power source 200 to the second load and electrically connected to the electrical path. The second switching element includes a bidirectional thyristor 12 and a bidirectional thyristor 512 that are semiconductor switches. A surge absorbing element (surge absorbing circuit 60) for reducing a surge voltage applied to the second switching element is connected between the AC power source 200 and the second load in parallel with the second switching element.

Therefore, even when the back electromotive force generated in the first load enters the second switching element when the first switching element interrupts the power supply to the first load, the surge voltage applied to the second switching element can be blocked The wave absorbing element is lowered. Therefore, the counter electromotive force occurring in the first load is less likely to cause switching between the opening and closing of the second switching element, and is less likely to cause the second load to operate briefly.

In the switching device 1 of the present embodiment, preferably, the surge absorbing element (surge absorbing circuit 60) is for lowering the surge voltage to a value lower than the turn-on voltage of the semiconductor switch. By using the surge absorbing element to lower the surge voltage to a value lower than the turn-on voltage, the semiconductor switch is suppressed by the surge voltage for a short period of time.

In the switching device 1 of the present embodiment, the first load may be an inductive load (the fan load 400 in this embodiment). When the power supply to the inductive load is interrupted, a back electromotive force occurs in the inductive load. Even if the counter electromotive force enters the second switching element, the surge absorbing element reduces the surge voltage applied to the second switching element, so switching between the opening and closing of the second switching element is suppressed.

In the switching device 1 of the present embodiment, the second load may be a lighting load 300 (eg, an LED illuminator). Even if the counter electromotive force occurring in the first load enters the second switching element when the power supply to the first load is interrupted, the surge absorbing element reduces the surge voltage applied to the second switching element, thus The switching between the opening and closing of the second switching element is suppressed. Therefore, even when the second load is an LED illuminator having high responsiveness, the case where the LED illuminator is briefly lit when the power supply to the first load is interrupted is suppressed.

The load control system of the present embodiment includes a switching device 1, a first load connected to the first terminals (load terminals 95 and 96), and a second load connected to the second terminals (load terminals 93 and 94). The first load is an inductive load (fan load 400) and the second load is an LED illuminator (lighting load 300). The surge absorbing element (surge absorbing circuit 60) is for reducing the application of a counter electromotive force occurring in the inductive load to the second switching element when the first switching element (contact 111) is turned off (bidirectional thyristor 12) The surge voltage.

Therefore, the surge absorbing element reduces the surge voltage applied to the second switching element by the counter electromotive force occurring in the inductive load when the first switching element is turned off. Therefore, the switching between the opening and closing of the second switching element caused by the counter electromotive force is suppressed. Therefore, even when the LED illuminator having high responsiveness is connected to the second terminal, the case where the LED illuminator is briefly lit when the first switching element is turned off is suppressed.

In the above-described switching device 1 of the present embodiment, the signal processing unit 40 stops the illumination load 300 and the fan load 400 after the operation holding period has elapsed from the time when the human sensor 70 stops the detection result of the human. However, the operation hold period can be adjustable. For example, the switching device 1 may include a setting switch (for example, a toggle switch or a rotary switch), and the setting period may be used to set the operation holding period to a desired period. The signal processing unit 40 may turn off the lighting load 300 and stop the fan load 400 immediately after the input of the detection signal from the human sensor 70 is stopped (ie, the human sensor 70 stops the detection of a human).

In the above-described switching device 1 of the present invention, the relays 10 and 11 are non-latch relays. However, relays 10 and 11 can be latched relays. When the relays 10 and 11 are latching relays, each of the relays 10 and 11 includes a set coil and a reset coil. When a current flows through the action coil, the contact is turned on, and even when the current carried to the set coil is stopped, the open state of the contact remains. When current flows through the return coil, the contact is closed, and even when the current carried to the return coil stops, the closed state of the contact remains.

In the switching device 1 of the present embodiment, the lighting load 300 and the fan load 400 are used as loads. However, the load of the switching device 1 is not limited to the lighting load 300 and the fan load 400, and may be other electrical devices.

The switching device 1 of the present embodiment controls the operation of the load based on the detection signal input from the human sensor 70 (as a triggering mode). However, the triggering method for changing the operational state of the load is not limited to the detection result of the human sensor 70 for a person. The switching device 1 can change the operational state of the load by using the operation performed by the operation unit or the receiving unit of the radio signal transmitted from the remote control transmitter as a trigger mode.

Although the present invention has been described with reference to the preferred embodiments thereof, many modifications and variations can be made without departing from the true spirit and scope of the invention.

1‧‧‧Switching device
10‧‧‧ Relay
11‧‧‧ Relay
12‧‧‧Two-way thyristor
20‧‧‧First drive circuit
21‧‧‧Switching elements
22‧‧‧Switching elements
30‧‧‧Switch circuit
31‧‧‧Optoelectronics
40‧‧‧Signal Processing Unit
50‧‧‧second drive circuit
51‧‧‧Optocoupler
52‧‧‧Switching elements
60‧‧‧ surge absorption circuit
70‧‧‧human sensor
80‧‧‧Power circuit
91‧‧‧Input terminal
92‧‧‧Input terminal
93‧‧‧Load terminal
94‧‧‧Load terminal
95‧‧‧Load terminal
96‧‧‧Load terminal
101‧‧‧Contacts
102‧‧‧Relay coil
111‧‧‧Contacts
112‧‧‧Relay coil
200‧‧‧AC power supply
300‧‧‧Lighting load
400‧‧‧fan load
511‧‧‧Light Emitting Diodes (LEDs)
512‧‧‧Two-way thyristor
C1‧‧‧ capacitor
C2‧‧‧ capacitor
C3‧‧‧ capacitor
C4‧‧‧ capacitor
D1‧‧‧ diode
D2‧‧‧ diode
DB1‧‧‧Rectifier
DB11‧‧‧DC output terminal
DB12‧‧‧DC output terminal
Gl‧‧ ‧ gate terminal
L1‧‧‧ coil
P1‧‧‧ Output埠
P2‧‧‧ Output埠
P3‧‧‧ Output埠
RT1‧‧‧First current path
RT2‧‧‧second current path
R1‧‧‧Resistors
R2‧‧‧ resistor
R3‧‧‧Resistors
R4‧‧‧Resistors
R5‧‧‧Resistors
R6‧‧‧Resistors
R7‧‧‧Resistors
R10‧‧‧Resistors
R11‧‧‧Resistors
T1‧‧‧ terminal
T2‧‧‧ terminal
ZD1‧‧‧Jenner diode
ZD2‧‧‧Jenner diode

Preferred embodiments of the present invention will now be described in further detail. Other features and advantages of the present invention will be more fully understood from the description of the appended claims.

1‧‧‧Switching device

10‧‧‧ Relay

11‧‧‧ Relay

12‧‧‧Two-way thyristor

20‧‧‧First drive circuit

21‧‧‧Switching elements

22‧‧‧Switching elements

30‧‧‧Switch circuit

31‧‧‧Optoelectronics

40‧‧‧Signal Processing Unit

50‧‧‧second drive circuit

51‧‧‧Optocoupler

52‧‧‧Switching elements

60‧‧‧ surge absorption circuit

70‧‧‧human sensor

80‧‧‧Power circuit

91‧‧‧Input terminal

92‧‧‧Input terminal

93‧‧‧Load terminal

94‧‧‧Load terminal

95‧‧‧Load terminal

96‧‧‧Load terminal

101‧‧‧Contacts

102‧‧‧Relay coil

111‧‧‧Contacts

112‧‧‧Relay coil

200‧‧‧AC power supply

300‧‧‧Lighting load

400‧‧‧fan load

511‧‧‧Light Emitting Diodes (LEDs)

512‧‧‧Two-way thyristor

C1‧‧‧ capacitor

C2‧‧‧ capacitor

C3‧‧‧ capacitor

C4‧‧‧ capacitor

D1‧‧‧ diode

D2‧‧‧ diode

DB1‧‧‧Rectifier

DB11‧‧‧DC output terminal

DB12‧‧‧DC output terminal

G1‧‧‧ gate terminal

L1‧‧‧ coil

P1‧‧‧ Output埠

P2‧‧‧ Output埠

P3‧‧‧ Output埠

RT1‧‧‧First current path

RT2‧‧‧second current path

R1‧‧‧Resistors

R2‧‧‧ resistor

R3‧‧‧Resistors

R4‧‧‧Resistors

R5‧‧‧Resistors

R6‧‧‧Resistors

R7‧‧‧Resistors

R10‧‧‧Resistors

R11‧‧‧Resistors

T1‧‧‧ terminal

T2‧‧‧ terminal

ZD1‧‧‧Jenner diode

ZD2‧‧‧Jenner diode

Claims (8)

A switching device comprising: a plurality of first terminals connected to a first load; a plurality of second terminals connected to a second load; a first switching element inserted and electrically connected to connect an AC power source to the first An electrical path of the load; and a second switching element interposed and electrically connected to an electrical path connecting the AC power source to the second load, wherein the second switching element comprises a semiconductor switch, and wherein the second switching element comprises a semiconductor switch A wave absorbing element is coupled between the AC power source and the second load in parallel with the second switching element, the surge absorbing element for reducing a surge voltage applied to the second switching element. The switching device of claim 1, wherein the surge absorbing element is configured to reduce the surge voltage to a voltage lower than a break over voltage of the semiconductor switch. The switching device of claim 1, wherein the first load is an inductive load. The switching device of claim 2, wherein the first load is an inductive load. The switching device of any one of claims 1 to 4, wherein the second load is an LED illuminator. The switching device of any one of claims 1 to 4, wherein the surge absorbing element comprises a series circuit of a resistor and a capacitor. The switching device of claim 5, wherein the surge absorbing element comprises a series circuit of a resistor and a capacitor. A load control system comprising: the switch device of claim 1 or 2; the first load connected to the first terminals; and the second load connected to the second terminals, Wherein the first load is an inductive load, and the second load is an LED illuminator, and wherein the surge absorbing element is configured to reduce the inductive when the first switching element is turned off A counter electromotive force occurring in the load is applied to a surge voltage of the second switching element.