JP2013171702A - Electronic automatic on/off device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic automatic on/off device capable of freely setting a lighting/extinguishing hysteresis without requiring a control power supply.SOLUTION: An electronic automatic on/off device comprises: an optical sensor circuit 110 detecting brightness; a triac 120 switching connection between a load 200 and an AC power supply 300; a rectification circuit 130 connected between a gate of the triac and a T1 terminal; a MOSFET 140, a resistor element 160, and a Zener diode 170 that are connected between DC terminals of the rectification circuit; and a voltage comparison circuit 150 energizing the gate of the MOSFET 140 on the basis of an output value of the optical sensor circuit to control a current, and thereby, performing energization control of the triac. An anode and a cathode of the Zener diode are connected to a ground terminal and a power supply input terminal of the voltage comparison circuit, respectively, and thereby, the voltage comparison circuit is operated by using a voltage between the terminals of the Zener diode.

Description

  The present invention relates to an electronic automatic flashing device for controlling energization / non-energization of a load according to ambient brightness. The present invention can be applied to, for example, an electronic flasher that controls lighting and extinguishing of a lighting device (for example, a streetlight).

  2. Description of the Related Art Conventionally, lighting devices using an automatic flasher are known. In such an illuminating device, ambient brightness can be detected, and the illuminating device can be automatically turned on and off according to the change in brightness. That is, by using the automatic flasher, the lighting device can be automatically turned on when the surroundings become dark, and the lighting device can be automatically turned off when the surroundings become bright.

  As an automatic flasher, one using a mechanical switch and one using an electronic switch such as a semiconductor switch element are known.

  As an automatic flasher using a mechanical switch (hereinafter also referred to as a mechanical automatic flasher), for example, a photoelectric conversion element using cadmium sulfide (CdS), a resistance heater, a bimetal switch (that is, a thermal switch) A device using a switch formed by bonding two metal plates having different expansion coefficients is known. In this automatic flasher, a current corresponding to the amount of light received by the photoelectric conversion element is supplied to the resistance heater, and the bimetal switch is automatically turned on / off by the heat generated thereby. Such an automatic flasher has an advantage that it is inexpensive, but has a disadvantage that the device life is short and the power consumption is large.

  On the other hand, as an automatic flasher using an electronic switch (hereinafter also referred to as an electronic automatic flasher), a photovoltaic device or cadmium sulfide is used as an optical sensor, and a triac (that is, a semiconductor comparison circuit) is used. A device for controlling the gate of a bidirectional thyristor has been put into practical use.

  In general, an electronic flasher has the advantages of longer device life and lower power consumption than a mechanical flasher, but it requires a power supply circuit and a control circuit to operate a semiconductor circuit, and the number of parts There is a problem that the cost is high.

  As an electronic automatic flashing device that solves such a problem, an apparatus described in Patent Document 1 is known. In the electronic automatic flasher disclosed in Patent Document 1, a triac is connected between an AC power source and a lighting load, and this triac is automatically turned on / off according to the amount of light received by the photovoltaic element. Control is in progress. Further, in this electronic automatic flasher, the circuit for controlling on / off of the triac is configured by two depletion type (normally ON type) MOSFETs (Metal Oxide Semiconductor Field Effect Transistors). The depletion type MOSFET is turned on when the gate is at the ground potential, and is turned off when the gate becomes a predetermined negative potential or less. These MOSFETs are connected in anti-series, and sources and gates are connected in common. Further, the drain of one MOSFET is connected to the gate of the triac, and the drain of the other MOSFET is connected to one current terminal of the triac. A photovoltaic element is provided between the common source and the common gate (see, for example, paragraph 0025 and FIG. 1 of Patent Document 1). According to such a configuration, when the surroundings are bright (that is, when the photovoltaic element generates a photocurrent), the gate of the depletion type MOSFET becomes a predetermined negative potential or less and the MOSFET is turned off. As a result, the triac gate goes to a low level, so that the triac is also turned off. Therefore, no current flows through the load. On the other hand, when the surrounding is dark, the gate of the depletion type MOSFET becomes the ground potential and the MOSFET is turned on. Thereby, since the gate of the triac becomes high level, the triac is also turned on, so that a current flows through the load. Such an electronic flasher has an advantage that a power supply circuit is unnecessary and there is almost no power consumption.

  However, the electronic automatic blinker of Patent Document 1 may malfunction when ambient brightness temporarily changes. For example, when the headlight light of an automobile is received by the photovoltaic element during lighting at night, the lighting device may be turned off.

  In order to eliminate such drawbacks, a hysteresis should be provided between the threshold illuminance when transitioning from the lit state to the unlit state and the threshold illuminance when shifting from the unlit state to the lit state. Is effective.

  On the other hand, in the electronic automatic blinker disclosed in Patent Document 2, a light emitting element is provided in the vicinity of the photovoltaic element. And the above-mentioned hysteresis is generated by turning on the light emitting element only when the lighting device is turned on. Further, in the electronic automatic flasher disclosed in Patent Document 3, a light shielding liquid crystal plate is provided in the vicinity of the photovoltaic element. The liquid crystal plate is used to reduce the amount of light received by the photovoltaic element when the lighting device is turned on, thereby generating the hysteresis as described above. Furthermore, in the electronic automatic flasher disclosed in Patent Document 4, a voltage monitoring circuit is provided to generate the hysteresis as described above.

  Since the electronic automatic blinkers of Patent Documents 2 to 4 described above have hysteresis of turning on / off, malfunctions are unlikely to occur. However, these electronic flashers have a complicated circuit, and thus have a drawback of high device cost and power consumption. Moreover, if it is going to cover the increase in power consumption with the electric power which a photovoltaic element produces | generates, a large sized photovoltaic element will be needed and will cause the further raise of apparatus cost.

  Further, according to the study of the present inventor, the lighting device using the electronic flasher of Patent Document 1 is dimmed when the ambient brightness is slightly lower than the vicinity of the boundary between turning on and off (that is, extremely (With low illuminance). Such a dimly lit state causes the lighting device to malfunction.

  In order to solve these problems, the present inventors have proposed an electronic flasher disclosed in Patent Document 5.

Japanese Patent Laid-Open No. 2000-100590 Japanese Patent Laid-Open No. 11-214177 Japanese Patent Laid-Open No. 11-214178 JP 11-214976 A Japanese Patent No. 4635037

  Since the electronic flasher disclosed in Patent Document 5 does not have a power supply circuit, a depletion type MOSFET is used in order to secure electric power for maintaining the operating state when the lamp is turned on.

  However, since the depletion type MOSFET is hardly on the market, it costs parts procurement.

  The problem of the present invention is that the hysteresis of energization / non-energization (turned on / off when the load is a light source) can be freely set, and the energization is completely performed when the ambient brightness is near the boundary between energization / non-energization. An electronic automatic flasher that can be turned on or off and does not require a control power supply is provided at a lower cost.

  An automatic flasher according to the present invention is connected between a photo sensor circuit that detects brightness using a photovoltaic element, a triac that switches connection between a load and an AC power source, a gate of the triac, and a T2 terminal. A rectifier, a triac control FET having a drain connected to the positive DC terminal of the rectifier circuit and a source connected to the negative DC terminal of the rectifier circuit, and a Zener diode having an anode connected to the negative DC terminal of the rectifier circuit And a current supply resistor element having one end connected to the positive DC terminal of the rectifier circuit and the other end connected to the cathode of the Zener diode, and the gate of the triac control FET based on the output value of the photosensor circuit. And a voltage comparison circuit that controls energization of the triac by controlling the current.

  In this electronic flasher, the anode and cathode of the Zener diode are connected to the ground terminal and the power supply input terminal of the voltage comparison circuit, respectively, so that the voltage comparison circuit operates using the voltage between the terminals of the Zener diode. ing.

  In the electronic flashing device according to the present invention, the gate current of the triac that is a switching element is controlled by a voltage comparison circuit that operates at, for example, about 1/100 of the trigger current of the triac gate. Then, a zener diode for passing a minute current is connected in parallel with the triac control FET for controlling the gate current of the triac. The voltage comparison circuit is operated by the voltage between the terminals of the Zener diode.

  By configuring the voltage comparator circuit with a voltage comparator (comparator) and flip-flop, the hysteresis for turning on / off can be easily set, and the amount of light received by the photosensor circuit is near the boundary of turning on / off. Even so, it is possible to provide an electronic flasher whose on / off state completely changes.

  In addition, since the current controlled by the photosensor circuit is very small, the photosensor can be miniaturized.

  Furthermore, since a power supply circuit is not required, it can be changed from the 3-wire type used in conventional flashers to a 2-wire type, resulting in a simple and easy-to-water-proof shape. Electronic flasher can be provided.

  Further, since a general normally-off type FET is used instead of a depletion type MOSFET, the cost of parts procurement can be further reduced.

It is a circuit diagram which shows the structure of the illuminating device using the electronic automatic blinker which concerns on 1st Embodiment. It is a circuit diagram which shows the structure of the illuminating device using the electronic flasher which concerns on 2nd Embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. In each figure, the arrangement relationship of each component is shown only schematically to the extent that the present invention can be understood, and the numerical conditions described below are merely examples.

(First embodiment)
With reference to FIG. 1, the structural example of the electronic flasher which concerns on 1st Embodiment is demonstrated. FIG. 1 is a circuit diagram showing an overall configuration of a lighting apparatus using the electronic flasher according to the first embodiment. As shown in FIG. 1, the lighting device of the first embodiment includes an electronic automatic flasher 100, a load 200, and an AC power supply 300.

  The electronic flasher 100 includes an optical sensor circuit 110, a triac 120, a rectifier circuit 130, a triac control FET (hereinafter also referred to as a MOSFET) 140, a voltage comparison circuit 150, a current supply resistance element (hereinafter simply referred to as a resistance element). 160), a Zener diode 170, a capacitor 180, and a diode 190.

  The optical sensor circuit 110 detects ambient brightness and outputs the detected light intensity as voltage signals P1 and P2. For this purpose, the optical sensor circuit 110 includes a photodiode 111, resistance elements 112 and 113, and capacitors 114 and 115.

  The photodiode 111 is a photoelectric conversion element (also referred to as a photovoltaic element) for detecting received light intensity. The cathode (negative electrode terminal) of the photodiode 111 is connected to the negative DC terminal D <b> 2 of the rectifier circuit 130. In this embodiment, G2711-01 manufactured by Hamamatsu Photonics was used as the photodiode 111. Note that instead of the photodiode 111, a solar battery cell, an LED having a photoelectric effect, or the like can be used.

  One end of the resistance element 112 is connected to the anode (positive electrode terminal) of the photodiode 111. The resistance element 113 has one end connected to the other end of the resistance element 112 and the other end connected to the cathode of the photodiode 111. The resistance elements 112 and 113 convert the current generated by the dielectric electromotive force of the photodiode 111 into a voltage signal indicating the detection result of the light intensity. In this embodiment, the voltage at the connection point between the anode of the photodiode 111 and the resistance element 112 is a signal P2, and the voltage at the connection point between the resistance elements 112 and 113 is a signal P1. In this embodiment, the resistance value of the resistance element 112 is 3 MΩ, and the resistance value of the resistance element 113 is 7 MΩ.

  The capacitor 114 is connected in parallel with the resistance elements 112 and 113 between the anode and the cathode of the photodiode 111. Capacitor 115 is connected in parallel with resistance element 113. Capacitors 114 and 115 can set a delay time from when the received light amount of the photodiode 111 changes until the light amount detection signals P1 and P2 change. In this embodiment, the capacitors 114 and 115 have a capacitance of 0.47 μF.

  The triac 120 is used for switching the connection between the load 200 and the AC power supply 300.

  The load 200 is connected to the T1 terminal of the triac 120 at one terminal and connected to one terminal of the AC power supply 300 at the other terminal. In this embodiment, the load 200 is a light source installed on a streetlight, for example. AC power supply 300 is connected to the T2 terminal of triac 120 at the other terminal. In this embodiment, STMicroelectronics BTA24 was used as the triac 120. In FIG. 1, the snubber circuit of the triac 120 is omitted.

  The electronic flasher 100 according to this embodiment is housed in, for example, a translucent housing and fixed to a utility pole or the like. Then, the AC power supply 300 is electrically connected by using two lead wires connected to the T1 terminal and the T2 terminal of the triac 120.

  The rectifier circuit 130 is a circuit that converts the gate output of the triac 120 from alternating current to direct current. For this reason, in the rectifier circuit 130, the AC terminal A1 is connected to the T2 terminal of the triac 120, and the AC terminal A2 is connected to the gate of the triac 120. In this embodiment, a bridge diode is used as the rectifier circuit 130.

  The MOSFET 140 controls the gate current of the triac 120 via the rectifier circuit 130. For this purpose, the drain of the MOSFET 140 is connected to the positive DC terminal D1 of the rectifier circuit 130, and the source is connected to the negative DC terminal D2 of the rectifier circuit 130. The MOSFET 140 used here is a normally OFF type FET. In this embodiment, Supertex STP85N15 was used as the MOSFET 140.

  The voltage comparison circuit 150 controls on / off of the MOSFET 140 based on the output signals P1, P2 of the photosensor circuit 110 and the reference voltages V1, V2. In this embodiment, an LMC555 manufactured by National Semiconductor is used as the voltage comparison circuit 150. The voltage comparison circuit 150 includes a flip-flop 151, a first comparator 152, a second comparator 153, resistance elements 154 to 156, and a MOSFET 157.

  The flip-flop 151 outputs a low level voltage when the reset signal R is input, and outputs a high level voltage when the set signal S is input. The flip-flop 151 is reset at a timing when the reset signal R rises to a high level (thus, outputs a low level), and is set at a timing when the set signal S rises to a high level (thus outputting a high level). It is configured to become). The output of the flip-flop 151 is used as the gate signal of the MOSFET 140.

  The first comparator 152 outputs a reset signal R when the signal P1 becomes larger than the reference voltage V1. As described above, the signal P1 is a voltage signal indicating the intensity of light received by the photodiode 111. Reference voltage V1 is a voltage corresponding to the first threshold value of the present invention, and corresponds to the value of signal P1 when energization of load 300 is terminated.

  The second comparator 153 outputs a set signal S when the signal P2 becomes smaller than the reference voltage V2. As described above, the signal P2 is a voltage signal indicating the intensity of light received by the photodiode 111. Reference voltage V2 is a voltage corresponding to the second threshold value of the present invention, and corresponds to the value of signal P2 when energization of load 300 is started.

  In the automatic flasher according to this embodiment, P1 and P2 are set such that the threshold illuminance when shifting from the lighting state to the unlit state is higher than the threshold illuminance when shifting from the unlit state to the lit state. , V1, V2 are set. Usually, it is considered that the ratio of the threshold illuminance when the light is turned on to the threshold illuminance when the light is turned off is preferably about 1.2 to 3.

  One end of the resistance element 154 is connected to the cathode of the Zener diode 170 via the power input terminal V + of the voltage comparison circuit 150, and the other end is connected to the negative input terminal of the first comparator 152. The resistor element 155 has one end connected to the other end of the resistor element 154 and the other end connected to the positive input terminal of the second comparator 153. Also, one end of the resistance element 156 is connected to the other end of the resistance element 155, and the other end is connected to the negative DC terminal D2 of the rectifier circuit 130 via the ground terminal GND.

  Furthermore, the anode of the diode 190 is connected to the connection point between the resistance elements 154 and 155, and the cathode of the diode 190 is connected to the negative DC terminal D 2 of the rectifier circuit 130. The diode 190 operates as a so-called reference voltage generation circuit, and the reference voltage V1 is determined by the diode 190. As a result, a voltage obtained by dividing the potential difference between the reference voltage V1 and the ground terminal GND by the resistance elements 155 and 156 is applied to the negative input terminal of the first comparator 152 and the positive input terminal of the second comparator 153. . When the LMC 555 is used as the voltage comparison circuit 150, the resistance values of the resistance elements 154 to 156 are each 100 kΩ, for example.

  The MOSFET 157 has a drain connected to the discharging input terminal, a source connected to the ground terminal GND, and a gate connected to the inverting output terminal of the flip-flop 151. The MOSFET 157 is originally provided in the LMC 555, but is not used in this embodiment.

  One end of the resistance element 160 is connected to the positive DC terminal D 1 of the rectifier circuit 130, and the other end is connected to the cathode of the Zener diode 170. The resistance element 160 is used to supply a small amount of current to the Zener diode 170. As the resistance element 160, for example, one having 20 kΩ or more can be used, but in this embodiment, it is set to 500 kΩ. The resistance element 160 may be replaced with a constant current diode of 5 mA or less, for example.

  The Zener diode 170 has a cathode connected to the resistance element 160 and an anode connected to the negative DC terminal D 2 of the rectifier circuit 130. In this embodiment, a Zener diode 170 having 5V is used.

  The capacitor 180 is connected in parallel with the Zener diode 170. The voltage generated by the Zener diode 170 is smoothed by the capacitor 180 and used as a power source for the voltage comparison circuit 150. In this embodiment, the capacitance of the capacitor 180 is 0.1 μF. Note that the capacitor 180 may not be provided depending on the application such as high speed.

  Next, the operation principle of the electronic flasher 100 shown in FIG. 1 will be described.

  First, the state of the electronic flasher 100 when the surroundings are bright will be described.

  When the surroundings are bright, the photodiode 111 receives ambient light, which generates an electromotive current. Therefore, a current flows through the resistance elements 112 and 113, and a voltage between the terminals is generated in the resistance elements 112 and 113. At this time, the voltage signals P1 ≧ V1 and P2 ≧ V2 are satisfied, so that the output of the first comparator 152 (reset signal R) is high level and the output of the second comparator (set signal S) is low level.

  Here, the flip-flop 151 is reset when the reset signal R rises to a high level, and when the reset signal R is at a high level and the set signal S is at a low level, the output of the voltage comparison circuit 150 becomes a low level, and the GND And the same voltage. Therefore, the gate voltage of the MOSFET 140 is at the same level as the source voltage. For this reason, the MOSFET 140 is in an off state.

  Therefore, the DC terminals D1 and D2 of the rectifier circuit 130 are connected via the resistance element 160 and the Zener diode 170. For this reason, a DC voltage substantially equal to the power supply voltage is applied between the DC terminals D1 and D2, thereby causing a very small current to flow through the resistance element 160 (for example, about 0.1 mA). As a result, since the current supplied to the gate of the triac 120 is very small, the triac 120 is off. Therefore, no current flows through the load 200. Note that the voltage comparison circuit 150 can operate even with a current of about 0.1 mA.

  Next, the operation of the electronic flasher 100 when the surroundings change from a bright state to a dark state will be described.

  As the surroundings become darker, the received light intensity of the photodiode 111 decreases, so the voltage values of the signals P1 and P2 also decrease. When P2 <V2, the set signal S output to the second comparator 153 becomes high level. In this embodiment, since the resistance values of the resistance elements 155 and 156 are equal, the set signal S is high when the voltage of the signal P2 falls below ½ of the voltage signal V1 (that is, the voltage generated by the diode 190). Become a level.

  When the set signal S rises, the output voltage of the voltage comparison circuit 150 becomes high level. This voltage is substantially the same voltage as the power supply input terminal V + of the voltage comparison circuit 150, and therefore, the power supply voltage is higher than the source voltage of the MOSFET 140. Here, the MOSFET 140 is turned on because the gate voltage increases.

  When the MOSFET 140 is turned on, the current flowing between the DC terminals D1 and D2 increases (for example, about 10 mA). As a result, the triac 120 is turned on, and a current flows through the load 200.

  While the triac 120 is kept on, the trigger current of the triac 120 flows for a moment near the zero cross. A momentary voltage is generated in the Zener diode 170 from the zero cross point until the trigger current flows, and as a result, the voltage comparison circuit 150 operates and holds the flip-flop 151.

  Next, the operation of the electronic flasher 100 when the surroundings change from a dark state to a bright state will be described.

  As the surroundings become brighter, the received light intensity of the photodiode 111 increases, so that the voltage values of the signals P1 and P2 increase. When P1 ≧ V1, the reset signal R output to the first comparator 152 becomes high level.

  When the reset signal R rises, the output of the flip-flop 151 is switched to a low level. As a result, the MOSFET 140 is turned off, so that no current flows through the load 200 according to the operation principle as described above.

  As described above, since the electronic flasher 100 according to this embodiment uses the flip-flop 151 to turn on / off the triac 120, it operates completely even near the boundary between lighting / extinguishing. Can be migrated.

  Furthermore, since the electronic flasher 100 performs the setting / resetting of the flip-flop 151 by the first and second comparators 152 and 153, the ON / OFF hysteresis setting is performed by setting the resistance value of the resistance elements 112 and 113 and the reference voltage. This can be done freely by setting V1. As described above, the reference voltage V2 is determined according to the set value of the reference voltage V1.

  In addition, the electronic flasher 100 of this embodiment does not need to provide a light emitting element, a liquid crystal plate, or the like to set hysteresis, and the power source of the voltage comparison circuit can be covered by a trigger current. Compared to the electronic automatic flashing device according to Patent Documents 2 to 4 described above, it is inexpensive.

  In addition, since it is possible to use a normally OFF type FET, it is possible to reduce the cost of parts procurement, and as a result, it is even less expensive than the electronic automatic flashing device according to Patent Document 5 described above. is there.

  Further, when a normally-off type FET is used, the occurrence of discharge (spark) can be reduced when connecting a new installation. That is, according to the electronic flasher 100 of this embodiment, it is possible to realize a complete OFF start that does not become an ON state when a new connection is established.

  In this embodiment, two types of voltage signals P1 and P2 are used as signals indicating the received light intensity. This is because the LMC 555 which is an existing semiconductor chip is used as the voltage comparison circuit 150. As can be seen from FIG. 1, when the LMC 555 is used, since the values of the resistance elements 154 to 156 are fixed, the reference voltage V2 of the second comparator 153 is determined according to the reference voltage V1 of the first comparator 152, and is separately The reference voltages V1 and V2 cannot be set independently. Therefore, in this embodiment, the resistor elements 112 and 113 are used to generate two types of voltage signals P1 and P2, and the received light intensity when the light is turned off and the received light intensity when the light is turned on are controlled by the voltage signals P1 and P2. doing. On the other hand, when using a voltage comparison circuit in which the reference voltages V1 and V2 can be set independently, it is possible to supply one voltage signal indicating the received light intensity to each comparator.

(Second Embodiment)
With reference to FIG. 2, the structural example of the electronic flasher which concerns on 2nd Embodiment is demonstrated. FIG. 2 is a circuit diagram showing an overall configuration of a lighting apparatus using the electronic flasher according to the second embodiment.

  The electronic automatic flashing device according to the second embodiment relates to the first embodiment in that it further includes an output control resistance element (hereinafter also simply referred to as a resistance element) 161 and an output control FET. Different from electronic flasher. Since the other components are common, redundant description is omitted.

  One end of the resistance element 161 is connected to the positive DC terminal D 1 of the rectifier circuit 130, and the other end is connected to the gate of the MOSFET 140. As the resistance element 161, for example, one having 100 kΩ or more can be used, but in this embodiment, it is set to 200 kΩ. The resistance element 161 may be replaced with a constant current diode.

  The MOSFET 157 described with reference to FIG. 1 is used as the output control FET 157. The drain of the MOSFET 157 is connected to the gate of the MOSFET 140, the source is grounded, and the gate is connected to the inverting output terminal of the flip-flop 151.

  In this configuration, when ON, that is, when the output Q of the flip-flop 151 is at a high level, the output of the inverting output terminal of the flip-flop 151 is at a low level, and the MOSFET 157 is turned off. In this case, a positive voltage is applied to the gate of the MOSFET 140 via the resistance element 161, and the MOSFET 140 is turned on.

  On the other hand, when OFF, that is, when the output Q of the flip-flop 151 is at a low level, the output of the inverting output terminal of the flip-flop 151 is at a high level, and the MOSFET 157 is turned on. In this case, the gate of the MOSFET 140 is at the ground potential, and the MOSFET 140 is turned off.

  According to this configuration, since the gate voltage applied to the MOSFET 140 at the time of ON is higher than that of the automatic flasher of the first embodiment, the operation stability is increased when using an FET that requires a high ON voltage.

DESCRIPTION OF SYMBOLS 100 Electronic automatic flasher 110 Photosensor circuit 111 Photodiode 112,113,154,155,156,160,161 Resistance element 114,115,180 Capacitor 120 Triac 130 Rectifier circuit 140,157 MOSFET
150 Voltage Comparison Circuit 151 Flip-flop 152 First Comparator 153 Second Comparator 170 Zener Diode 190 Diode 200 Load 300 AC Power Supply

An automatic flasher according to the present invention is connected between a photo sensor circuit that detects brightness using a photovoltaic element, a triac that switches connection between a load and an AC power source, a gate of the triac, and a T2 terminal. A rectifier circuit, a normally-off type TRIAC control FET whose drain is connected to the positive DC terminal of the rectifier circuit, and a source connected to the negative DC terminal of the rectifier circuit, and an anode connected to the negative DC terminal of the rectifier circuit Zener diode, one end of which is connected to the positive DC terminal of the rectifier circuit, the other end of which is connected to the cathode of the Zener diode, and a triac control FET based on the output value of the optical sensor circuit. A voltage comparison circuit for controlling energization of the triac by energizing the gate to control the current;

Claims (8)

An optical sensor circuit for detecting brightness using a photovoltaic element;
A TRIAC that switches the connection between the load and the AC power supply;
A rectifier circuit connected between the gate of the triac and the T2 terminal;
A triac control FET having a drain connected to the positive DC terminal of the rectifier circuit, and a source connected to the negative DC terminal of the rectifier circuit;
A Zener diode having an anode connected to the negative DC terminal of the rectifier circuit;
A current supply resistor element having one end connected to the positive DC terminal of the rectifier circuit and the other end connected to the cathode of the Zener diode;
A voltage comparison circuit that controls energization of the triac by controlling the current by energizing the gate of the triac control FET based on the output value of the photosensor circuit;
By connecting the anode and the cathode of the Zener diode to the ground terminal and the power supply input terminal of the voltage comparison circuit, respectively, the voltage comparison circuit is operated using the voltage between the terminals of the Zener diode. Electronic flasher characterized by. 2. The electronic flashing device according to claim 1, wherein the voltage comparison circuit uses an output of a flip-flop as a gate signal of the triac control FET. An output control resistor element having one end connected to the positive DC terminal of the rectifier circuit and the other end connected to the gate of the triac control FET;
The voltage comparison circuit further includes an output control FET,
The source of the output control FET is grounded, the drain is connected to the gate of the triac control FET, and the gate is connected to the inverting output terminal of the flip-flop. Electronic flasher.   The electronic automatic flashing device according to any one of claims 1 to 3, wherein a resistance value of the current supply resistance element is 20 kΩ or more. The electronic automatic flashing device according to any one of claims 1 to 3, wherein a constant current diode of 5 mA or less is used instead of the current supply resistance element. When energized, the voltage between the terminals of the Zener diode is generated using the instantaneous voltage generated from the AC power supply to the gate of the triac via the rectifier circuit, the current supply resistor element, and the Zener diode. The electronic automatic flashing device according to any one of claims 1 to 5. A reference voltage generation circuit including one diode;
The electronic flashing device according to any one of claims 1 to 6, wherein the photovoltaic element is formed of a photodiode made of one cell. A translucent housing that houses the photosensor circuit, the triac, the rectifier circuit, and the voltage comparison circuit;
The electronic flasher according to any one of claims 1 to 7, further comprising two lead wires respectively connected to a T1 terminal and a T2 terminal of the triac.