TW201517469A - Load control device - Google Patents

Abstract

A load control device comprises: a bidirectional switching element; a diode bridge circuit having a first and second AC input terminal respectively connected to the first and the second source electrode of the bidirectional switching element; a power source circuit for converting the output voltage between the plus terminal and the minus terminal of the diode bridge circuit to a constant voltage; a level conversion circuit for electrically connecting the plus terminal and the minus terminal to each other with a prescribed impedance; and a gate drive circuit. The gate drive circuit supplies the first and second gate electrodes with a drive voltage or a drive current from the power source circuit when a control signal is in high level. The bipolar transistor in the level conversion circuit is turned on when the control signal is in high level.

Description

Load control device

The present invention relates generally to load control devices and, more particularly, to load control devices including dual direction switching elements.

As the load control device, for example, a 2-wire type AC switch 100a having the configuration shown in FIG. 10 is known (refer to Japanese Laid-Open Patent Publication No. 2011-176921; hereinafter referred to as Document 1).

The 2-wire AC switch 100a is an AC switch for connecting a commercial AC power source 101 and a load 102 such as a lighting fixture. The two-wire AC switch 100a includes a bidirectional switching element 103, a full-wave rectifier 104, a power supply circuit 105, a drive circuit (a first gate drive circuit 107, a second gate drive circuit 108), and a control circuit 106.

The bidirectional switching element 103 is a double gate switching element composed of a Group III nitride semiconductor in which a current flows in two directions and a flow of the current is turned on or off. The bidirectional switching element 103 includes: a switch terminal S11 and a switch terminal S12 as a switch (on/off); the control terminal G11 and the control terminal G12 are connected to control the conduction and disconnection of the flow of the current. And a substrate terminal SUB electrically connected to form a substrate of the bidirectional switching element 103. Here, the commercial AC power supply 101, the load 102, and the bidirectional switching element 103 (the switch terminal S11 and the switch terminal S12) are connected in series to form a closed circuit.

The full-wave rectifier 104 is a bridge diode that is connected between the switch terminal S11 and the switch terminal S12 to perform full-wave rectification of the AC power supplied from the commercial AC power supply 101.

The power supply circuit 105 is a circuit that supplies a full-wave rectified voltage from the output of the full-wave rectifier 104 to a DC power supply. The power supply required for the first gate driving circuit 107, the second gate driving circuit 108, and the control circuit 106 is supplied from the power supply circuit 105.

When the commercial AC power supply 101 supplies electric power to the load 102, the control circuit 106 turns the bidirectional switching element 103 into an ON state. At this time, the control circuit 106 controls the first gate driving circuit 107 and the second gate driving circuit 108, and the first gate driving circuit 107 and the second gate driving circuit 108 respectively control the control terminal G11 and the control terminal of the bidirectional switching element 103. G12, outputting a control signal having a voltage higher than a threshold voltage of a gate corresponding to the control terminal G11 and the control terminal G12. Thereby, the control circuit 106 causes the bidirectional switching element 103 to be in an on state.

On the other hand, when the control circuit 106 blocks the supply of electric power to the load 102 from the commercial AC power supply 101, the bidirectional switching element 103 is turned off. At this time, the control circuit 106 controls the first gate driving circuit 107 and the second gate driving circuit 108, and the first gate driving circuit 107 and the second gate driving circuit 108 respectively control the control terminal G11 and the control terminal of the bidirectional switching element 103. G12, outputting a control signal having a voltage lower than a threshold voltage of a gate corresponding to the control terminal G11 and the control terminal G12. Thereby, the control circuit 106 turns the bidirectional switching element 103 into a disconnected state.

In other words, when the bidirectional switching element 103 is turned on, the first gate driving circuit 107 and the second gate driving circuit 108 generate control signals and output them to the corresponding control terminals G11 and G12.

The control circuit 106 is a circuit that controls the first gate drive circuit 107 and the second gate drive circuit 108 as described above.

More specifically, the external setting unit 109 transmits a signal indicating whether or not power is supplied from the commercial AC power source 101 to the load 102 to the control circuit 106. Based on the signal transmitted, the control circuit 106 outputs a control signal to the input terminal SIN1 of the first gate drive circuit 107 and the input terminal SIN2 of the second gate drive circuit 108.

The first gate drive circuit 107 and the second gate drive circuit 108 output control signals to the control terminals G11 and G12 of the bidirectional switch element 103 from the output terminals OUT1 and OUT2, respectively, based on the control signals from the control circuit 106. The switching operation of the bidirectional switching element 103 is controlled.

In Document 1, the specific circuit configuration of each of the first gate drive circuit 107 and the second gate drive circuit 108 in the two-wire AC switch 100a is not clearly described.

Further, although the device is expected to be more compact in size, in the load control device, when the gate drive circuit includes a level shift circuit for changing the voltage level, it tends to be more compact. In the load control device, when the gate drive circuit drives the bidirectional switching element with a transformer, it tends to be difficult to miniaturize.

In view of the above, it is an object of the present invention to provide a load control device that can be miniaturized.

A load control device according to the present invention includes: a bidirectional switching element including a first gate electrode, a second gate electrode, a first source electrode, and a second source electrode, respectively, which can be respectively used for the first gate electrode A predetermined driving voltage is applied between the first source electrode and the second source electrode and the second source electrode, and the first source electrode and the second source electrode are electrically connected to each other. a circuit for supplying power from an AC power source to a load; a diode bridge circuit having a first AC input terminal connected to the first source electrode and a second AC input terminal being connected to the second source electrode; The output voltage between the positive terminal of the diode bridge circuit and the negative terminal of the diode bridge circuit can be constantly voltage-regulated; the level conversion circuit can have a predetermined impedance between the positive terminal and the negative terminal And a gate driving circuit for supplying the first gate electrode and the second gate electrode of the bidirectional switching element from the power supply circuit for turning on the bidirectional switching element The driving voltage or the predetermined driving current; and the gate driving circuit can input a control signal for controlling the turning on and off of the bidirectional switching element, and the control signal is at a high level, from the power circuit, to the a gate electrode and the second gate electrode supply the driving voltage or the driving current, the level conversion circuit comprising a bipolar transistor, the collector terminal of the bipolar transistor being connected to the positive terminal, and the emitter terminal The sub-terminal is connected to the negative terminal, and the control signal is input to the base terminal. When the control signal is at a high level, the bipolar transistor is turned on.

The load control device according to the present invention can be miniaturized.

(Embodiment 1) Hereinafter, a load control device 1a according to the present embodiment will be described with reference to Figs. 1 to 3 .

The load control device 1a is a load control device including a bidirectional switching element 2 provided in a supply circuit from the AC power supply 8 to the load 9.

The bidirectional switching element 2 includes a first gate electrode G1, a second gate electrode G2, a first source electrode S1, and a second source electrode S2, and is respectively paired with the first gate electrode G1 and the first source electrode S1. A predetermined driving voltage is applied between the second gate electrode G2 and the second source electrode S2, thereby turning on between the first source electrode S1 and the second source electrode S2.

The load control device 1a includes a diode bridge circuit 3, the first AC input terminal 31 is connected to the first source electrode S1, the second AC input terminal 32 is connected to the second source electrode S2, and the power supply circuit 4 is connected to the second source electrode S2. The output voltage between the positive terminal 33 of the polar body bridge circuit 3 and the negative terminal 34 of the diode bridge circuit 3 is constantly voltage-stabilized; the level conversion circuit 5a is between the positive terminal 33 and the negative terminal 34 with a predetermined impedance. And the gate driving circuit 6a supplies a driving voltage from the power supply circuit 4 to the first gate electrode G1 and the second gate electrode G2 of the bidirectional switching element 2.

The gate driving circuit 6a can input a control signal CS for controlling the turning on and off of the bidirectional switching element 2, and when the control signal CS is at the high level VH, the first gate electrode G1 and the second gate are connected from the power supply circuit 4. The electrode G2 supplies a driving voltage. The level conversion circuit 5a includes a bipolar transistor Q5. The collector terminal of the bipolar transistor Q5 is connected to the positive terminal 33, the emitter terminal is connected to the negative terminal 34, and the base terminal is input with a control signal CS. In the level shift circuit 5a, the bipolar transistor Q5 is turned on when the control signal CS is at the high level VH. Thereby, the load control device 1a can be downsized.

The components of the load control device 1a will be described in detail below.

As shown in FIG. 1, the load control device 1a of the present embodiment includes a bidirectional switching element 2, a diode bridge circuit 3, a power supply circuit 4, a level conversion circuit 5a, a gate drive circuit 6a, and a terminal 7. The load control device 1a includes a control circuit 100.

In the load control device 1a, a series circuit of the AC power supply 8 and the load 9 is connected between the first source electrode S1 and the second source electrode S2 of the bidirectional switching element 2. Therefore, the load control device 1a includes the first main terminal 21 and the second main terminal 22 that respectively connect the first source electrode S1 and the second source electrode S2 of the bidirectional switching element 2, and the first main terminal 21 and the first main terminal 21 Between the main terminals 22, a series circuit of the AC power source 8 and the load 9 can be connected.

In the load control device 1a, the bidirectional switching element 2 is connected in series between the AC power source 8 and the load 9 with an AC power source 8 and a load 9. Specifically, the bidirectional switching element 2 constitutes a closed circuit as a supply circuit together with the AC power supply 8 and the load 9. The supply circuit constitutes a closed circuit including at least a circuit in which the AC power supply 8, the load 9, and the bidirectional switching element 2 are connected in series. Thereby, the load control device 1a can control the conduction and disconnection of the load 9. The AC power source 8 is, for example, a commercial power source. The load 9, for example, is a lighting load (dimmer, etc.).

The bidirectional switching element 2 is stable in both the conduction state (on state) and the off (disconnection state) in any bias direction between the first source electrode S1 and the second source electrode S2. State AC switching element. The bidirectional switching element 2 is a normally closed type heterojunction field effect transistor including a first gate electrode G1, a second gate electrode G2, a first source electrode S1, and a second source electrode S2. Transistor: HFET). At this time, in the bidirectional switching element 2, the first source electrode S1 constitutes the first main electrode, and the second source electrode S2 constitutes the second main electrode.

As the HFET, for example, an AlGaN/GaN-based HFET can be used. In the bidirectional switching element 2, the first source electrode S1 is connected to the first main terminal 21, and the second source electrode S2 is connected to the second main terminal 22.

As the bidirectional switching element 2, the bidirectional switching element 103 of the 2-wire type AC switch of Fig. 10 can also be used.

The two-direction switching element 2 may be formed by connecting two metal oxide semiconductor field effect transistors (MOSFETs) in series in reverse. In the bidirectional switching element 2, for example, an reinforced (normally closed) n-channel MOSFET is used as the MOSFET, and the drain electrodes of the two MOSFETs are connected to each other. Further, each MOSFET includes a built-in diode (also referred to as a "body diode" or a "parasitic diode"). Each built-in diode is used as a rectifier diode.

As the MOSFET, for example, a Si-type MOSFET can be used. The MOSFET is not limited to a Si-type MOSFET, and for example, a SiC-based MOSFET or a GaN-based MOSFET can be used.

The diode bridge circuit 3, as shown in FIGS. 2 and 3, is a bridge-connected full-wave rectifier circuit of four diodes D01, D02, D03, and D04.

In the diode bridge circuit 3, a series circuit of two diodes D01 and D02 is connected in parallel, and a series circuit of two diodes D03 and D04 is connected, thereby connecting four diodes D01 and D02 in a bridge manner. , D03 and D04. Specifically, the cathode of the diode D01 is connected to the anode of the diode D02, the cathode of the diode D03 is connected to the anode of the diode D04, the cathode of the diode D02 is connected to the cathode of the diode D04, and the diode D01 The anode is connected to the anode of the diode D03. In the diode bridge circuit 3, the connection point of the two diodes D01 and D02 constitutes the first AC input terminal 31, and the connection point of the two diodes D03 and D04 constitutes the second AC input terminal 32. In the diode bridge circuit 3, the connection points of the two diodes D02 and D04 constitute a positive terminal (positive polarity output terminal) 33, and the connection points of the two diodes D01 and D03 constitute a negative terminal (negative polarity output) Terminal) 34.

Briefly, the diode bridge circuit 3 includes a first AC input terminal 31, a second AC input terminal 32, a positive terminal 33, and a negative terminal 34. In the diode bridge circuit 3, the first AC input terminal 31 is connected to the first main terminal 21 and the first source electrode S1, and the second AC input terminal 32 is connected to the second main terminal 22 and the second source electrode S2.

The diode bridge circuit 3 has a function of full-wave rectifying an AC voltage from an AC power source 8 connecting the first source electrode S1 and the second source electrode S2 of the bidirectional switching element 2. Briefly, the diode bridge circuit 3 converts the AC voltage from the AC power source 8 through a full-wave rectified voltage, and outputs it between the positive terminal 33 and the negative terminal 34.

In the load control device 1a, the power supply circuit 4 is connected between the positive terminal 33 and the negative terminal 34 of the diode bridge circuit 3.

The power supply circuit 4 is a constant voltage circuit that converts the output voltage of the diode bridge circuit 3 into a predetermined DC voltage.

The power supply circuit 4 is a constant voltage circuit including an npn transistor Q4, a Zener diode ZD4, a resistor R4, and a smoothing capacitor C4. The constant voltage circuit is connected between the positive terminal 33 of the diode bridge circuit 3 and the output terminal 41 of the high potential side of the power supply circuit 4, and a series constant voltage circuit of the npn transistor Q4 is interposed.

In the power supply circuit 4, a series circuit of a resistor R4 and a Zener diode ZD4 is connected between the positive terminal 33 and the negative terminal 34 of the diode bridge circuit 3. In the power circuit 4, the first end of the resistor R4 is connected to the positive terminal 33 of the diode bridge circuit 3, the second terminal of the resistor R4, the cathode of the Zener diode ZD4, and the anode of the Zener diode ZD4. Connect the negative terminal 34 of the diode bridge circuit 3. Further, in the power supply circuit 4, the collector terminal of the npn transistor Q4 is connected to the first end of the resistor R4, the base terminal, and the connection point of the resistor R4 and the Zener diode ZD4. Further, in the power supply circuit 4, the smoothing capacitor C4 is connected in parallel between the emitter terminal of the npn transistor Q4 and the anode of the Zener diode ZD4 in parallel with the series circuit of the npn transistor Q4 and the Zener diode ZD4. The smoothing capacitor C4 is formed of a capacitor having polarity such as an aluminum electrolytic capacitor.

The output voltage VDD of the power supply circuit 4 is the voltage across the smoothing capacitor C4. The power supply circuit 4 keeps the output voltage VDD constant. The output voltage VDD of the power supply circuit 4 is the Zener voltage from the Zener diode ZD4, and the value of the voltage between the base terminal and the emitter terminal of the npn transistor Q4 is subtracted. Moreover, the circuit configuration of the power supply circuit 4 is an example, and the circuit configuration is not particularly limited as long as it is a constant voltage circuit.

The load control device 1a includes a terminal 7 that inputs a control signal CS generated by the control circuit 100. The control circuit 100 is a circuit that controls the gate drive circuit 6a. The control circuit 100 outputs a control signal CS to the terminal 7. Further, the terminal 7 may be constituted by an output terminal of the control circuit 100 for outputting the control signal CS. Further, the control circuit 100 can be configured, for example, by a microcomputer having an appropriate program. The power required by the control circuit 100 can also be supplied from the power supply circuit 4.

The control circuit 100 turns on the bidirectional switching element 2 when power is supplied from the AC power source 8 to the load 9. At this time, the control circuit 100 controls the gate drive circuit 6a, and the gate drive circuit 6a outputs the higher value than the first gate electrode G1 and the first gate electrode G1 and the second gate electrode G2 of the bidirectional switch element 2. The driving voltage of the first gate threshold voltage between the source electrode S1 and the second gate threshold voltage between the second gate electrode G2 and the second source electrode S2. Thereby, the control circuit 100 turns on the bidirectional switching element 2. Further, in the bidirectional switching element 2, the first gate threshold voltage and the second gate threshold voltage are preferably the same.

Further, when the control circuit 100 supplies power to the load 9 from the AC power source 8, the bidirectional switching element 2 is turned off. At this time, the control circuit 100 controls the gate drive circuit 6a, and the gate drive circuit 6a outputs the threshold value lower than the first gate threshold voltage to the first gate electrode G1 and the second gate electrode G2 of the bidirectional switch element 2, The voltage of the second gate threshold voltage. Thereby, the control circuit 100 turns off the bidirectional switching element 2.

The control circuit 100 is connected to the external setting unit 200 via the connection terminal 300. The control circuit 100 transmits a signal indicating whether or not the power is supplied from the AC power source 8 to the load 9 from the setting unit 200. The control circuit 100 outputs a control signal CS based on the signal transmitted from the setting unit 200. Specifically, when the control unit 100 transmits a signal indicating that power is supplied from the AC power source 8 to the load 9 from the setting unit 200, the control signal CS is at the high level VH, and the instruction is not to supply power to the load 9 from the AC power source 8 (interruption) When the signal is supplied from the AC power source 8 to the load 9, the control signal CS is at the low level VL. For example, the setting unit 200 outputs, to the control circuit 100, a switching signal for instructing switching of supply and disconnection of power from the AC power source 8 to the load 9 at a predetermined frequency and duty ratio. At this time, the control circuit 100 outputs, as the control signal CS, a PWM signal whose voltage is switched between the high level VH and the low level VL in accordance with the frequency and duty ratio of the switching signal from the setting unit 200. The gate drive circuit 6a controls the switching operation of the bidirectional switching element 2 based on the control signal CS.

The gate driving circuit 6a has a function of supplying a driving voltage for turning on the bidirectional switching element 2 from the power supply circuit 4 to the first gate electrode G1 and the second gate electrode G2 of the bidirectional switching element 2.

The gate driving circuit 6a includes a MOSFET 61, an inverter 62, a first diode D1, a second diode D2, and two resistors R61 and R62.

The gate drive circuit 6a, as the MOSFET 61, employs an enhancement type p-channel MOSFET. In the MOSFET 61, the source terminal is connected to the output terminal 41 on the high potential side of the power supply circuit 4, and the 汲 terminal is connected to the junction of the anodes of the first diode D1 and the second diode D2, and the gate terminal is connected. The output terminal of the inverter 62. The cathodes of the first diode D1 and the second diode D2 are connected to the first gate electrode G1 and the second gate electrode G2, respectively. The resistor R61 is connected between the first source electrode S1 and the first gate electrode G1 of the bidirectional switching element 2, and the resistor R62 is connected to the second source electrode S2 and the second gate electrode G2 of the bidirectional switching element 2. between. In the inverter 62, the input terminal is connected to the terminal 7. Briefly, the inverter 62 inverts the control signal CS from the terminal 7 and inputs it to the gate terminal of the MOSFET 61. Therefore, in the gate driving circuit 6a, when the control signal CS is at the low level VL, the output of the inverter 62 is at the high level, and the MOSFET 61 is turned off. On the other hand, in the gate driving circuit 6a, when the control signal CS is at the high level VH, the output of the inverter 62 is at the low level, and the MOSFET 61 is turned on.

That is, as shown in Fig. 1, in the load control device 1a of the present embodiment, the gate drive circuit 6a is constituted by a switch circuit 63a, a first parallel circuit 64, and a second parallel circuit 65.

The switch circuit 63a of the present embodiment includes an input unit 66a that connects the output terminal 41 on the high potential side of the power supply circuit 4, and an output unit 67a. When the control signal CS is at the high level VH, the output unit 67a is supplied from the input unit 66a. electric power.

In one example, the switch circuit 63a is composed of a MOSFET 61 interposed between the input unit 66a and the output unit 67a, and an inverter 62. For example, in the switch circuit 63a, when the control signal CS input from the inverter 62 is at the high level VH, the MOSFET 61 is turned on, and the power from the input unit 66a is supplied to the output unit 67a.

The first parallel circuit 64 of the present embodiment is interposed between the output portion 67a of the switch circuit 63a and the first gate electrode G1, and is connected to the bidirectional switch between the first gate electrode G1 and the first source electrode S1. Element 2. When the control signal CS is at the high level VH, the first parallel circuit 64 applies a driving voltage between the first gate electrode G1 and the first source electrode S1.

In one example, the first parallel circuit 64 is composed of a first diode D1 and a resistor (first parallel resistor) R61. In the first diode D1, the anode is connected to the output portion 67a, and the cathode is connected to the first gate electrode G1. The resistor R61 connects the connection point between the anode of the first diode D1 and the first gate electrode G1 and the first source electrode S1.

The second parallel circuit 65 of the present embodiment is interposed between the output portion 67a of the switch circuit 63a and the second gate electrode G2, and is connected to the bidirectional switch between the second gate electrode G2 and the second source electrode S2. Element 2. When the control signal CS is at the high level VH, the second parallel circuit 65 applies a driving voltage between the second gate electrode G2 and the second source electrode S2.

In one example, the second parallel circuit 65 is composed of a second diode D2 and a resistor (second parallel resistor) R62. In the second diode D2, the anode is connected to the output portion 67a, and the cathode is connected to the second gate electrode G2. The resistor R62 connects the connection point between the anode of the second diode D2 and the second gate electrode G2 and the second source electrode S2.

The level conversion circuit 5a is provided between the diode bridge circuit 3 and the power supply circuit 4. The level shift circuit 5a has a function of turning on between the positive terminal 33 and the negative terminal 34 of the diode bridge circuit 3 with a predetermined impedance Imp1. The level conversion circuit 5a includes a bipolar transistor Q5. The collector terminal of the bipolar transistor Q5 is connected to the positive terminal 33, the emitter terminal is connected to the negative terminal 34, and the base terminal is input with a control signal CS. The level conversion circuit 5a includes a resistor R51, a base terminal of the bipolar transistor Q5, and is connected to the terminal 7 via a resistor R51.

In the level conversion circuit 5a, when the control signal CS is at the low level VL, the bipolar transistor Q5 is turned off, and the positive terminal 33 and the negative terminal 34 of the diode bridge circuit 3 are rendered non-conductive.

The level shifting circuit 5a turns on the bipolar transistor Q5 when the control signal CS is at the high level VH, and turns on between the positive terminal 33 and the negative terminal 34 of the diode bridge circuit 3 with a predetermined impedance Imp1. Here, in the present embodiment, the predetermined impedance Imp1 is the on-resistance of the bipolar transistor Q5, which is slightly zero.

2 and 3 are explanatory diagrams of the operation of the load control device 1a when the control signal CS is at the high level VH.

In the load control device 1a, a smoothing capacitor C4 from the power supply circuit 4 is formed to supply a current path of a gate current to the first gate electrode G1 and the second gate electrode G2, and when the ? control signal CS is at a high level VH, the bidirectional direction is maintained. The conduction state of the switching element 2 supplies electric power to the load 9 from the AC power source 8. In Figures 2 and 3, this current path is indicated by a dashed line.

In FIG. 2, the polarity of the AC voltage of the AC power source 8 is indicated by a dashed line, and the polarity of the current flowing in the direction indicated by the arrow B1 in FIG. 2 (the AC power source 8 applies a positive voltage to the first main terminal 21). In the following, the current channel formed in the "first period" (hereinafter, referred to as "the first current channel CP1"). The first current channel CP1 is a smoothing capacitor C4 of the power supply circuit 4 → a MOSFET 61 of the gate driving circuit 6 a → a first diode D1 and a second diode D2 of the gate driving circuit 6 a → a second source of the bidirectional switching element 2 The pole electrode S2 → the diode D04 of the diode bridge circuit 3 → the channel of the bipolar transistor Q5 → the smoothing capacitor C4 of the level shifting circuit 5a.

In FIG. 3, the polarity of the AC voltage of the AC power source 8 is indicated by a dashed line, and is a period in which the current flows in the direction indicated by the arrow B2 in FIG. 3 (the AC power source 8 applies a positive voltage to the second main terminal 22). In the following, the current channel formed by the "second period" is referred to as "the second current channel CP2". The second current channel CP2 is a smoothing capacitor C4 of the power supply circuit 4 → a MOSFET 61 of the gate driving circuit 6 a → a first diode D1 and a second diode D2 of the gate driving circuit 6 a → a first source of the bidirectional switching element 2 The pole electrode S1 → the diode D02 of the diode bridge circuit 3 → the channel of the bipolar transistor Q5 → the smoothing capacitor C4 of the level shifting circuit 5a.

Briefly, in the load control device 1a, the smoothing capacitor C4 from the power supply circuit 4 can be used to supply both the first gate electrode G1 and the second gate electrode G2 of the bidirectional switching element 2 by the level conversion circuit 5a. Each of the first current channel CP1 and the second current channel CP2 of the gate current. In other words, when the control signal CS is at the high level VH, the MOSFET 61 is turned on, and the bipolar transistor Q5 is turned on, whereby the gate electrode is supplied from the power supply circuit 4 to both the first gate electrode G1 and the second gate electrode G2. The current paths CP1 and CP2 of the current are electrically connected between the first source electrode S1 and the second source electrode S2 of the bidirectional switching element 2. Thereby, in the load control device 1a, the level shift circuit for generating the potentials based on the first source electrode S1 and the second source electrode S2, respectively, can be provided without the gate drive circuit 6a. The bidirectional switching element 2 is driven by a voltage based on the negative terminal 34 of the diode bridge circuit 3. Thereby, the load control device 1a can be downsized.

In particular, in the load control device 1a, the transformer for driving the switching element can be omitted, and the bidirectional switching element 2 can be driven, so that the size of the device can be reduced.

As described above, the load control device 1a of the present embodiment includes the bidirectional switching element 2, the diode bridge circuit 3, the power supply circuit 4, the level conversion circuit 5a, and the gate drive circuit 6a as shown in Fig. 1 . The bidirectional switching element 2 is provided in a supply circuit from the AC power source 8 to the load 9. The bidirectional switching element 2 includes a first gate electrode G1, a second gate electrode G2, a first source electrode S1, and a second source electrode S2, and is respectively paired with the first gate electrode G1 and the first source electrode S1. A predetermined driving voltage is applied between the second gate electrode G2 and the second source electrode S2, whereby the first source electrode S1 and the second source electrode S2 are electrically connected to each other. In the diode bridge circuit 3, the first AC input terminal 31 is connected to the first source electrode S1, and the second AC input terminal 32 is connected to the second source electrode S2. The power supply circuit 4 constantly voltages the output voltage between the positive terminal 33 of the diode bridge circuit 3 and the negative terminal 34 of the diode bridge circuit 3. The level shift circuit 5a turns on between the positive terminal 33 and the negative terminal 34 with a predetermined impedance. The gate drive circuit 6a supplies a driving voltage for turning on the bidirectional switching element 2 from the power supply circuit 4 to the first gate electrode G1 and the second gate electrode G2 of the bidirectional switching element 2. The gate driving circuit 6a can input a control signal CS for controlling the turning on and off of the bidirectional switching element 2, and when the control signal CS is at the high level VH, the first gate electrode G1 and the second gate are connected from the power supply circuit 4. The electrode G2 supplies a driving voltage. The level conversion circuit 5a includes a bipolar transistor Q5. The collector terminal of the bipolar transistor Q5 is connected to the positive terminal 33, the emitter terminal is connected to the negative terminal 34, and the base terminal is input with a control signal CS. The level shift circuit 5a turns on the bipolar transistor Q5 when the control signal CS is at the high level VH.

Thereby, the load control device 1a of the present embodiment can be downsized.

Hereinafter, a load control device 1b according to a modification of the load control device 1a of the present embodiment will be described with reference to Fig. 4 . The load control device 1b according to the modification does not include the level conversion circuit 5a of the load control device 1a of the first embodiment, and the level conversion circuit 5b is replaced with the load control device 1a of the first embodiment. The same components as those of the load control device 1a of the first embodiment are denoted by the same reference numerals and will not be described.

The level conversion circuit 5b has a circuit configuration similar to that of the level conversion circuit 5a, and includes a phase of the first resistor R52 connecting the emitter terminal of the bipolar transistor Q5 and the negative terminal 34 of the diode bridge circuit 3. different.

The level shifting circuit 5b turns on the bipolar transistor Q5 when the control signal CS is at the high level VH, and turns on between the positive terminal 33 and the negative terminal 34 of the diode bridge circuit 3 with a predetermined impedance Imp2. Here, in the present modification, the predetermined impedance Imp2 is a combined resistance value of the on-resistance of the bipolar transistor Q5 and the resistance value of the first resistor R52. The on-resistance value of the bipolar transistor Q5 is slightly zero, so the predetermined impedance Imp2 can be regarded as the resistance value of the first resistor R52.

In the load control device 1b, the level conversion circuit 5b includes the first resistor R52, whereby the current flowing through the level conversion circuit 5b can be made constant current, and the first gate electrode of the bidirectional switching element 2 is limited. The gate current flowing through G1 and the second gate electrode G2. As a result, in the load control device 1b, the first resistor R52 functions as a current limiting resistor, and the gate drive circuit 6a can achieve a lower current consumption than the load control device 1a.

As described above, in the load control device 1b of the present modification, as shown in FIG. 4, the level conversion circuit 5b further includes an emitter terminal connecting the bipolar transistor Q5 and a negative terminal 34 of the diode bridge circuit 3. The first resistor R52 is between. Thereby, the power consumption of the gate drive circuit 6a can be reduced.

(Embodiment 2) Hereinafter, a load control device 1c according to the present embodiment will be described with reference to Figs. 5 to 7B. The same components as those of the load control device 1a of the first embodiment are denoted by the same reference numerals, and the description thereof will be appropriately omitted.

The load control device 1c of the present embodiment does not include the gate drive circuit 6a of the load control device 1a of the first embodiment, and the gate drive circuit 6c is replaced by the gate drive circuit 6c.

The gate drive circuit 6c supplies a predetermined drive current ID for turning on the bidirectional switch element 2 from the power supply circuit 4 to the first gate electrode G1 and the second gate electrode G2 of the bidirectional switch element 2.

As shown in FIG. 6, when the control signal CS changes from the low level VL to the high level VH, the gate drive circuit 6c of the present embodiment supplies the first gate electrode G1 and the second gate electrode G2 as the gate current is larger than The current of the drive current ID is set to time T1. The gate drive circuit 6c changes the control signal CS from the high level VH to the low level VL from the time when the current setting time T1 greater than the drive current ID is supplied to the first gate electrode G1 and the second gate electrode G2. At the time, the drive current ID is continuously supplied to the first gate electrode G1 and the second gate electrode G2.

As shown in FIG. 5, the gate driving circuit 6c includes an npn transistor Q1 and a current mirror circuit 60c including a first pnp transistor Q2, a second pnp transistor Q3, and a second resistor R1.

In the npn transistor Q1, the emitter terminal is connected to the negative terminal 34 of the diode bridge circuit 3 to be grounded, and the control signal CS is input to the base terminal. The base terminal of the npn transistor Q1 is preferably connected to the terminal 7 via a resistor R63. Briefly, the gate drive circuit 6c preferably includes a resistor R63. The resistor R63 is included, whereby the noise component of the control signal CS and the like can be suppressed, so that the operation of the npn transistor Q1 can be stabilized.

In the first pnp transistor Q2, the emitter terminal is connected to the output terminal 41 on the high potential side of the power supply circuit 4, and is connected between the base terminal and the collector terminal.

In the second pnp transistor Q3, the emitter terminal is connected to the output terminal 41 on the high potential side of the power supply circuit 4, and the collector terminal is connected to the first gate electrode G1 via the first diode D1 and via the second diode D2. The second gate electrode G2 is connected to the base terminal, and the base terminal of the first pnp transistor Q2 is connected.

The second resistor R1 is connected between the collector terminal of the npn transistor Q1 and the collector terminal of the first pnp transistor Q2. The gate drive circuit 6c includes a capacitor C1 connected in parallel between both ends of the second resistor R1. Thereby, the set time T1 is determined by the time constant of the parallel circuit of the second resistor R1 and the capacitor C1.

The current mirror circuit 60c is a circuit that flows a current equal to the current flowing through the second resistor R1 toward the second pnp transistor Q3. Further, in the current mirror circuit 60c, the second pnp transistor Q3 constitutes an output transistor.

The operation of the gate drive circuit 6c of the load control device 1c will be described below.

Here, first, a load control device 1e (see FIG. 11) having a basic configuration of the present embodiment will be described. In the load control device 1e of the basic configuration, the gate drive circuit 6e does not include the capacitor C1. In the load control device 1e of the basic configuration, the current mirror circuit 60c constitutes a constant current circuit (also referred to as a "constant current source"), and outputs a certain gate to the first gate electrode G1 and the second gate electrode G2, respectively. Current.

The operation of the bidirectional switching element 2 of the load control device 1e of this basic configuration will be described based on the equivalent circuits shown in Figs. 7A and 7B. 7A and 7B are operation examples of the first period (the polarity of the AC power source 8 and the period in which the current flows in the direction indicated by the arrow B1 in Fig. 2). In FIGS. 7A and 7B, "+V" is the potential (>0) of the first main terminal 21 (see FIG. 5), and "0V" is the potential of the second main terminal 22 (see FIG. 5). In Figs. 7A and 7B, the current mirror circuit 60c is indicated by a symbol of a constant current source. 7A and 7B, the first transistor Tr1 including the first gate electrode G1 and the first source electrode S1 and the transistor Tr2 including the second gate electrode G2 and the second source electrode S2 are connected. The circuit of each of the drain electrodes represents the bidirectional switching element 2.

Fig. 7A is an equivalent circuit of an important portion of the load control device 1e basically constituted after the control signal CS changes from the low level VL to the high level VH. In the load control device 1e of the basic configuration, after the constant current source 60c of the gate drive circuit 6e starts supplying the gate current to the bidirectional switching element 2, the gate current passes through the second diode D2 toward the second side of the low potential side. The gate electrode G2 of the transistor Tr2 flows, and the second transistor Tr2 is turned on. On the other hand, before the second transistor Tr2 is turned on, the first diode D1 connected to the gate electrode G1 of the first transistor Tr1 is reversely biased, so that the gate current does not flow to the first transistor Tr1.

Fig. 7B is an equivalent circuit immediately after an important portion of the second transistor Tr2 is turned on. In the load control device 1e of the basic configuration, after the second transistor Tr2 is turned on, the first diode D1 is biased, the first transistor Tr1 on the high potential side is also turned on, and the bidirectional switching element 2 is turned on.

In other words, in the load control device 1e having the basic configuration, the gate drive circuit 6e supplies a predetermined drive current to the first gate electrode G1 and the second gate electrode G2 from the power supply circuit 4 when the control signal CS is at the high level VH. . Further, the load control device 1e having a basic configuration outputs a constant drive current ID while the control signal CS is at the high level VH.

On the other hand, in the load control device 1c of the present embodiment, when the control signal CS changes from the low level VL to the high level VH, the first gate electrode G1 and the second gate electrode G2 are supplied as the gate current is larger than the drive. The current of the current ID sets the time T1. That is, in the load control device 1c of the present embodiment, the capacitor C1 is connected between both ends of the second resistor R1. Therefore, the gate drive circuit 6c supplies a current larger than the charge of the capacitor C1 to the first and second gate electrodes G1 and G2 while the capacitor C1 is being charged.

Thereby, in the load control device 1c, the bidirectional switching element 2 is turned on, the current in the transient state is increased, and the bidirectional switching element 2 is surely turned on more quickly, and thereafter, the bidirectional switching element 2 is kept in a stable state. The current is constant, whereby current consumption can be reduced. The period of the transition state is usually about several ns to several μs. As a result, in the load control device 1c, when the period of the high level VH of the control signal CS is sufficiently longer than the period of the transient state, the current consumption can be reduced. Therefore, the set time T1 may be set, for example, within a range of about 2 to 10 times the period of the transition state. Further, in the present embodiment, the set time T1 can be determined by the time constant of the parallel circuit of the second resistor R1 and the capacitor C1.

That is, as shown in Fig. 5, in the load control device 1c of the present embodiment, the gate drive circuit 6c is composed of a switch circuit 63c, a first parallel circuit 64, and a second parallel circuit 65.

The switch circuit 63c of the present embodiment includes an input unit 66c that connects the output terminal 41 on the high potential side of the power supply circuit 4, and an output unit 67c. When the control signal CS is at the high level VH, the power from the input unit 66c is output to the output unit. 67c supply.

In one example, the switch circuit 63c includes an npn transistor Q1, a current mirror circuit 60c including a first pnp transistor Q2, a second pnp transistor Q3, and a second resistor R1, and a capacitor C1. A current mirror circuit 60c is interposed between the input unit 66c and the output unit 67c. For example, when the control signal CS input to the npn transistor Q1 is at the high level VH in the switch circuit 63c, the npn transistor Q1 is turned on, and the power from the input unit 66c is supplied to the output unit 67c.

The first parallel circuit 64 of the present embodiment is interposed between the output portion 67c of the switch circuit 63c and the first gate electrode G1. When the control signal CS is at the high level VH, the first parallel circuit 64 applies a driving voltage between the first gate electrode G1 and the first source electrode S1.

The second parallel circuit 65 of the present embodiment is interposed between the output portion 67c of the switch circuit 63c and the second gate electrode G2. When the control signal CS is at the high level VH, the second parallel circuit 65 applies a driving voltage between the second gate electrode G2 and the second source electrode S2.

Similarly, in the load control device 1e having the basic configuration shown in FIG. 11, the gate drive circuit 6e is composed of a switch circuit 63e, a first parallel circuit 64, and a second parallel circuit 65.

The switch circuit 63e is composed of an npn transistor Q1 and a current mirror circuit 60c including a first pnp transistor Q2, a second pnp transistor Q3, and a second resistor R1. For example, when the control signal CS input to the npn transistor Q1 is at the high level VH, the switching circuit 63e turns on the npn transistor Q1, and supplies the power from the input unit 66e to the output unit 67e.

Fig. 8 shows a gate drive circuit 6ca according to a modification of the load control device 1c of the present embodiment. In the gate drive circuit 6ca, the capacitor C1 of the gate drive circuit 6c is not provided, and the third resistor R2 and the npn transistor (second npn transistor) Q8 are included, which is different from the gate drive circuit 6c. In the third resistor R2, the first end is connected to the junction of the collector terminal of the first pnp transistor Q2 and the second resistor R1, and the second terminal is connected to the collector terminal of the npn transistor Q8. In the npn transistor Q8, the emitter terminal is connected to the negative terminal 34 of the diode bridge circuit 3, and the base terminal is connected to the terminal 7 of the input control signal CS (hereinafter also referred to as "the first control signal CS"). Terminal 7a is additionally provided. The terminal 7a receives a second control signal CS2 for turning on and off the npn transistor Q8. The second control signal CS2 is a signal that rises from the low level VLa toward the high level VHa, and is synchronized with the timing of the rise of the first control signal CS, and is maintained at a low level VHa for a period T2 and then at a lower level VLa. The second control signal CS2 of the input terminal 7a is preferably outputted by the control circuit 100, for example.

In the configuration of Fig. 8, the current of the drive current ID when the current does not flow to the third resistor R2 is equal to the set time T2 of the second resistor R1 and the third resistor R2. Thereby, in the gate drive circuit 6ca of the modified example, the bidirectional switching element 2 is turned on, and the current in the transient state is increased, so that the bidirectional switching element 2 is surely turned on more quickly, and thereafter, the bidirectional switching element 2 is kept at The current in the steady state is constant, whereby the current consumption can be reduced.

In the load control device 1c of the present embodiment, the gate drive circuit 6c is included, whereby the set time T1 is determined by the time constant of the parallel circuit of the second resistor R1 and the capacitor C1, so that the gate drive circuit is modified as compared with the modified example. At 6ca, the circuit configuration can be simplified.

The load control device 1c according to the present embodiment and the modified example and the load control device 1e having the basic configuration may not include the level conversion circuit 5a, and may be replaced with, for example, the load control device according to the modification of the load control device 1a of the first embodiment. The level conversion circuit 5b in 1b (refer to FIG. 4).

As described above, in the load control device 1c of the present embodiment and the modification, and the load control device 1e having the basic configuration, the gate drive circuit (6c; 6ca; 6e), the first gate of the bidirectional switching element 2 from the power supply circuit 4 The electrode electrode G1 and the second gate electrode G2 supply a predetermined drive current ID for turning on the bidirectional switching element 2. The gate drive circuit (6c; 6ca; 6e) supplies the drive current ID to the first gate electrode G1 and the second gate electrode G2 from the power supply circuit 4 when the control signal CS is at the high level VH.

Further, in the load control device 1c according to the present embodiment and the modification, as shown in FIG. 6, the gate drive circuit (6c; 6ca) is just opposite to the first gate when the control signal CS changes from the low level VL to the high level VH. The electrode electrode G1 and the second gate electrode G2 supply a current setting time (T1; T2) larger than the drive current ID.

Thereby, the bidirectional switching element 2 is turned on, and the current in the transient state is increased, so that the bidirectional switching element 2 can be surely turned on more quickly. Then, the current of the bidirectional switching element 2 in the steady state is kept constant, whereby current consumption can be reduced.

As described above, in the load control device 1c of the present embodiment, as shown in FIG. 5, the gate drive circuit 6c includes the npn transistor Q1 and the first pnp transistor Q2, the second pnp transistor Q3, and the second resistor R1. Current mirror circuit 60c. In the npn transistor Q1, the emitter terminal is connected to the negative terminal 34 to be grounded, and the control signal CS is input to the base terminal. In the first pnp transistor Q2, the emitter terminal is connected to the output terminal 41 on the high potential side of the power supply circuit 4, and is connected between the base terminal and the collector terminal. In the second pnp transistor Q3, the emitter terminal is connected to the output terminal 41 on the high potential side of the power supply circuit 4, and the collector terminal is connected to the first gate electrode G1 via the first diode D1 and via the second diode D2. The second gate electrode G2 is connected to the base terminal, and the base terminal of the first pnp transistor Q2 is connected. The second resistor R1 is connected between the collector terminal of the npn transistor Q1 and the collector terminal of the first pnp transistor Q2. The capacitor C1 is connected in parallel between the two ends of the second resistor R1. The set time T1 is determined by the time constant of the parallel circuit of the second resistor R1 and the capacitor C1.

Thereby, the circuit configuration can be simplified.

(Embodiment 3) Hereinafter, a load control device 1d according to this embodiment will be described with reference to Fig. 9 . The same components as those of the load control device 1c of the second embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

The load control device 1d of the present embodiment does not include the gate drive circuit 6c of the load control device 1c of the second embodiment, and the gate drive circuit 6d is used instead.

The gate driving circuit 6d includes a current mirror circuit 60d in which the second pnp transistor Q3 is not provided, and the second pnp transistor Q31 and the third pnp transistor Q32 are replaced. In the current mirror circuit 60d, the base terminal and the collector terminal of the first pnp transistor Q21 are connected. In the current mirror circuit 60d, the base terminal of the second pnp transistor Q31 and the base terminal of the third pnp transistor Q32 are connected to the base terminal of the first pnp transistor Q21. In the gate drive circuit 6d, the emitter terminals of the first to third pnp transistors Q21, Q31, and Q32 are connected to the output terminal 41 on the high potential side of the power supply circuit 4. In the gate driving circuit 6d, the collector terminal of the second pnp transistor Q31 is connected to the anode of the second diode D2, and the collector terminal of the third pnp transistor Q32 is connected to the anode of the first diode D1.

The gate drive circuit 6d is designed to have the same mutual characteristics of the first 1pnp transistor Q21, the second pnp transistor Q31, and the third pnp transistor Q32. Thereby, the gate drive circuit 6d can flow a current equal in magnitude to the current flowing through the first pnp transistor Q21 to the second pnp transistor Q31 and the third pnp transistor Q32. Thereby, in the gate driving circuit 6d, the second pnp transistor Q31 and the third pnp transistor Q32 constitute a current source. That is, the gate drive circuit 6d includes two current sources that correspond to the first gate electrode G1 and the second gate electrode G2 in a one-to-one manner.

That is, as shown in Fig. 9, in the load control device 1d of the present embodiment, the gate drive circuit 6d is composed of a switch circuit 63d, a first parallel circuit 64, and a second parallel circuit 65.

The switch circuit 63d of the present embodiment includes an input unit 66d that connects the output terminal 41 on the high potential side of the power supply circuit 4, and an output unit 67d. When the control signal CS is at the high level VH, the power from the input unit 66d is output to the output unit. 67d supply.

The output portion 67d of the switch circuit 63d of the present embodiment includes a first output terminal 671d and a second output terminal 672d. The switch circuit 63d supplies the power from the input unit 66d to the first output terminal 671d and the second output terminal 672d when the control signal CS is at the high level VH.

In one example, the switch circuit 63d is composed of an npn transistor Q1 and a current mirror circuit 60d including a first pnp transistor Q21, a second pnp transistor Q31, a third pnp transistor Q32, and a second resistor R11. A current mirror circuit 60d is interposed between the input terminal 66d and the output terminal 67d. For example, in the switch circuit 63d, when the control signal CS input to the npn transistor Q1 is at the high level VH, the npn transistor Q1 is turned on, and the power from the input unit 66d is applied to the output unit 67d (the first output terminal 671d and the second output terminal). 672d) Supply.

The first parallel circuit 64 of the present embodiment is interposed between the first output end 671d (output portion 67d) of the switch circuit 63d and the first gate electrode G1. When the control signal CS is at the high level VH, the first parallel circuit 64 applies a driving voltage (first driving voltage) between the first gate electrode G1 and the first source electrode S1.

The second parallel circuit 65 of the present embodiment is interposed between the second output terminal 672d (output portion 67d) of the switch circuit 63d and the second gate electrode G2. When the control signal CS is at the high level VH, the second parallel circuit 65 applies a driving voltage (second driving voltage) between the second gate electrode G2 and the second source electrode S2.

Further, the characteristics of the bidirectional switching element 2 may include, for example, the first transistor Tr1 including the first gate electrode G1 and the first source electrode S1 (see FIG. 7A) and the second gate electrode G2. The second transistor Tr2 of the second source electrode S2 (see FIG. 7A) has a difference in mutual crystal characteristics and the like.

On the other hand, in the load control device 1d, the gate drive circuit 6d includes two current sources that correspond to the first gate electrode G1 and the second gate electrode G2 in a one-to-one manner, so that the two-way switch can be eliminated. The difference in driving performance of the difference in the characteristics of the component 2.

The load control device 1d of the present embodiment may not include the level conversion circuit 5a, and may be replaced with, for example, the level conversion in the load control device 1b (see FIG. 4) of the modification of the load control device 1a of the first embodiment. Circuit 5b.

As described above, in the load control device 1d of the present embodiment, as shown in FIG. 9, the gate drive circuit 6d includes two currents corresponding to the first gate electrode G1 and the second gate electrode G2 in a one-to-one manner. source.

Specifically, the gate driving circuit 6d includes an npn transistor Q1 and a current mirror circuit 60d including a first pnp transistor Q21, a second pnp transistor Q31, a third pnp transistor Q32, and a second resistor R11. In the npn transistor Q1, the emitter terminal is connected to the negative terminal 34 to be grounded, and the control signal CS is input to the base terminal. In the first pnp transistor Q21, the emitter terminal is connected to the output terminal 41 on the high potential side of the power supply circuit 4, and is connected between the base terminal and the collector terminal. In the third pnp transistor Q32, the emitter terminal is connected to the output terminal 41 on the high potential side of the power supply circuit 4, and the terminal is connected to the first gate electrode G1 via the first diode D1, and the base terminal is connected to the first pnp. The base terminal of crystal Q21. In the second pnp transistor Q31, the emitter terminal is connected to the output terminal 41 on the high potential side of the power supply circuit 4, and the terminal is connected. The second gate electrode G2 is connected via the second diode D2, and the base terminal is connected to the first pnp. The base terminal of crystal Q21. The second resistor R11 is connected between the collector terminal of the npn transistor Q1 and the collector terminal of the first pnp transistor Q21.

Thereby, the difference in driving performance due to the difference in characteristics between the first transistor Tr1 and the second transistor Tr2 of the bidirectional switching element 2 can be eliminated.

In the above, the configuration of the present invention is described in the first to third embodiments, and the present invention is not limited to the configurations of the first to third embodiments. For example, the configuration of the first to third embodiments may be combined as appropriate. Further, the present invention can be appropriately modified as long as it does not escape the technical concept.

C4‧‧‧Smoothing capacitor
CS‧‧‧Control signal
D1‧‧‧1st dipole
D2‧‧‧2nd Diode
G1‧‧‧1st gate electrode
G2‧‧‧2nd gate electrode
Imp1‧‧‧ Impedance
Q4 npn‧‧‧O crystal
Q5‧‧‧Bipolar transistor
R4‧‧‧ resistance
R51‧‧‧ resistance
R61, R62‧‧‧ resistance
S1‧‧‧1st source electrode
S2‧‧‧2nd source electrode
VDD‧‧‧ output voltage
VH‧‧‧ high standard
VL‧‧‧low standard
ZD4‧‧‧Zina diode
1a‧‧‧Load control device
2‧‧‧Double-direction switching elements
3‧‧‧Diode Bridge Circuit
4‧‧‧Power circuit
5a‧‧‧bit conversion circuit
6a‧‧‧ brake drive circuit
7‧‧‧ Terminal
8‧‧‧AC power supply
9‧‧‧load
21‧‧‧1st main terminal
22‧‧‧2nd main terminal
31‧‧‧1st AC input terminal
32‧‧‧2nd AC input terminal
33‧‧‧ positive terminal
34‧‧‧negative terminal
41‧‧‧ Output
61‧‧‧ MOSFET
62‧‧‧Inverter
63a‧‧‧Switch circuit
64‧‧‧1st parallel circuit
65‧‧‧2nd parallel circuit
66a‧‧ Input Department
67a‧‧‧Output Department
100‧‧‧Control circuit
200‧‧‧Setting Department
300‧‧‧Connecting terminal

Fig. 1 is a circuit diagram of a load control device of the first embodiment. Fig. 2 is an explanatory view showing the operation of the load control device of the first embodiment. Fig. 3 is an explanatory view showing the operation of the load control device of the first embodiment. Fig. 4 is a circuit diagram showing a modification of the load control device of the first embodiment. Fig. 5 is a circuit diagram of a load control device of the second embodiment. Fig. 6 is an explanatory view showing the operation of the load control device of the second embodiment. 7A and 7B are schematic operation explanatory views of a load control device according to a second embodiment. Fig. 8 is a circuit diagram of a gate drive circuit according to a modification of the load control device of the second embodiment. Fig. 9 is a circuit diagram of a load control device of the third embodiment. Figure 10 is a circuit diagram of a conventional 2-wire AC switch. Fig. 11 is a circuit diagram showing a basic configuration of a load control device according to a second embodiment.

C4‧‧‧Smoothing capacitor

CS‧‧‧Control signal

D1‧‧‧1st dipole

D2‧‧‧2nd Diode

G1‧‧‧1st gate electrode

G2‧‧‧2nd gate electrode

Imp1‧‧‧ Impedance

Q4‧‧‧npn transistor

Q5‧‧‧Bipolar transistor

R4‧‧‧ resistance

R51‧‧‧ resistance

R61, R62‧‧‧ resistance

S1‧‧‧1st source electrode

S2‧‧‧2nd source electrode

VDD‧‧‧ output voltage

VH‧‧‧ high standard

VL‧‧‧low standard

ZD4‧‧‧Zina diode

1a‧‧‧Load control device

2‧‧‧Double-direction switching elements

3‧‧‧Diode Bridge Circuit

4‧‧‧Power circuit

5a‧‧‧bit conversion circuit

6a‧‧‧ brake drive circuit

7‧‧‧ Terminal

8‧‧‧AC power supply

9‧‧‧load

21‧‧‧1st main terminal

22‧‧‧2nd main terminal

31‧‧‧1st AC input terminal

32‧‧‧2nd AC input terminal

33‧‧‧ positive terminal

34‧‧‧negative terminal

41‧‧‧ Output

61‧‧‧ MOSFET

62‧‧‧Inverter

63a‧‧‧Switch circuit

64‧‧‧1st parallel circuit

65‧‧‧2nd parallel circuit

66a‧‧ Input Department

67a‧‧‧Output Department

100‧‧‧Control circuit

200‧‧‧Setting Department

300‧‧‧Connecting terminal

Claims (7)

A load control device includes: a bidirectional switching element including a first gate electrode, a second gate electrode, a first source electrode, and a second source electrode, wherein the first gate electrode and the first gate electrode are respectively A predetermined driving voltage is applied between the first source electrode and between the second gate electrode and the second source electrode, and the first source electrode and the second source electrode are electrically connected to each other. The bidirectional switching element is provided in a supply circuit for supplying power from the AC power source to the load; the diode bridge circuit is connected to the first AC input terminal to the first source electrode, and the second AC input is connected to the second source electrode. a power supply circuit that can constantly voltage the output voltage between the positive terminal of the diode bridge circuit and the negative terminal of the diode bridge circuit; the level conversion circuit causes the positive terminal with a predetermined impedance The negative terminal is electrically connected to each other; and the gate driving circuit is configured to supply the first gate electrode and the second gate electrode of the bidirectional switching element from the power supply circuit for turning on the bidirectional switching element The driving voltage or the predetermined driving current; the brake drive a driving circuit capable of inputting a control signal for controlling conduction and disconnection of the bidirectional switching element; and when the control signal is at a high level, the first gate electrode and the second gate electrode are from the power supply circuit Supplying the driving voltage or the driving current, the level converting circuit comprises a bipolar transistor, the collector terminal of the bipolar transistor is connected to the positive terminal, the emitter terminal is connected to the negative terminal, and The base terminal inputs the control signal, and when the control signal is at a high level, the bipolar transistor is turned on. The load control device of claim 1, wherein the level conversion circuit further includes a first resistor connected between the emitter terminal of the bipolar transistor and the negative terminal. The load control device of claim 1 or 2, wherein the gate drive circuit, when the control signal changes from a low level to a high level, is greater than the current of the drive current, the first gate electrode and the first 2 The gate electrode is supplied for a set period of time. The load control device of claim 3, wherein the gate drive circuit comprises an npn transistor, and a current mirror circuit having a first pnp transistor, a second pnp transistor, and a second resistor; an emitter terminal of the npn transistor The sub-connector is connected to the negative terminal and grounded, and the control signal is input to the base terminal thereof; the emitter terminal of the first pnp transistor is connected to the output end of the high-potential side of the power supply circuit, and is connected to the base terminal and the collector terminal The emitter terminal of the second pnp transistor is connected to the output terminal of the high potential side of the power supply circuit; and the collector terminal is connected to the first gate electrode via the first diode, and a diode is connected to the second gate electrode; and a base terminal is connected to a base terminal of the first pnp transistor; the second resistor is connected to the collector terminal of the npn transistor and the first pnp transistor A capacitor is connected in parallel between the terminals of the second resistor; the set time is determined by a time constant of the parallel circuit of the second resistor and the capacitor. The load control device of claim 1 or 2, wherein the gate drive circuit comprises two current sources, the two current sources respectively corresponding to the first gate electrode and the second gate in a one-to-one manner electrode. The load control device according to claim 3, wherein the gate drive circuit includes two current sources, and the two current sources respectively correspond to the first gate electrode and the second gate electrode in a one-to-one manner. The load control device according to claim 1 or 2, wherein the gate drive circuit is composed of: a switch circuit including an input portion connected to an output end of the high potential side of the power supply circuit, and an output portion; When the control signal is at a high level, power from the input unit is supplied to the output unit; the first parallel circuit is disposed between the output portion of the switch circuit and the first gate electrode, and is connected in parallel When the control signal is at a high level between the first gate electrode and the first source electrode, the driving voltage is applied between the first gate electrode and the first source electrode; and the second parallel circuit And being disposed between the output portion of the switch circuit and the second gate electrode, and connected in parallel between the second gate electrode and the second source electrode, and when the control signal is at a high level, The driving voltage is applied between the second gate electrode and the second source electrode.