TWI810977B - Turn signal control circuit - Google Patents

Abstract

A turn signal control circuit. The turn signal control circuit includes: a control circuit, a voltage regulator circuit, a voltage detection circuit, an output circuit, a differential amplifier circuit and a load detection circuit. The voltage regulator circuit is electrically connected to the control circuit. The voltage regulator circuit is connected to an input voltage source. The voltage detection circuit is electrically connected to the control circuit and the voltage regulator circuit. The output circuit is electrically connected to the control circuit, the voltage detection circuit and the voltage regulator circuit. The differential amplifier circuit is electrically connected to the control circuit, the output circuit, the voltage detection circuit and the voltage regulator circuit. The load detection circuit is electrically connected to the control circuit and the voltage regulator circuit.

Description

turn signal control circuit

The invention relates to a direction light control circuit, in particular to a direction light control circuit which can avoid malfunction.

Due to the increasing popularity of light-emitting diode lamps, the turn signal control circuit of the vehicle must provide a small current to the light-emitting diode lamps, and also avoid malfunctions caused by leakage currents in various circuits in the vehicle.

The technical problem to be solved by the present invention is to provide a direction light control circuit for the deficiencies of the prior art. The directional light control circuit includes a control circuit; a voltage stabilizing circuit electrically connected to the control circuit, the voltage stabilizing circuit is connected to an input voltage source to receive an input voltage, and converts the input voltage into a DC input voltage to The control circuit; a voltage detection circuit, electrically connected to the control circuit and the voltage stabilization circuit; an output circuit, electrically connected to the control circuit, the voltage detection circuit, and the voltage stabilization circuit; a differential an amplifying circuit electrically connected to the control circuit, the output circuit, the voltage detection circuit and the voltage stabilizing circuit; a load detection circuit electrically connected to the control circuit and the voltage stabilizing circuit; a first A switch, electrically connected to the differential amplifier circuit and the load detection circuit; and a load switch, connected to the load detection circuit and the first switch.

One of the beneficial effects of the present invention is that the directional light control circuit provided by the present invention can provide an output with a small load current in response to the load. It is also possible to judge the load status through the detection voltage of multiple circuits, and it can effectively avoid malfunction caused by leakage current.

In order to further understand the features and technical content of the present invention, please refer to the following detailed description and drawings related to the present invention. However, the provided drawings are only for reference and description, and are not intended to limit the present invention.

SYS: turn signal control circuit

1: Slider

2: Control circuit

3, 3A, 3B: voltage detection circuit

4: Output circuit

5: Differential amplifier circuit

6: Load detection circuit

8: Light-emitting diode lamp load

D1: the first diode

D2: second diode

D3: The third diode

D4: The fourth diode

R1: first impedance

R2: second impedance

R3: the third impedance

R4: the fourth impedance

R5: fifth impedance

R6: sixth impedance

R7: seventh impedance

R8: Eighth impedance

R9: ninth impedance

R10: Tenth impedance

R11: Eleventh impedance

R12: Twelfth impedance

R13: Thirteenth impedance

R14: Fourteenth impedance

Z1: The first Zener diode

Q1: The first switching element

Q2: Second switching element

Q3: The third switching element

Q4: The fourth switching element

Q5: Fifth switching element

8-1,8-2: Light-emitting diode lamps

C1: the first capacitor

C2: second capacitor

C3: the third capacitor

C4: the fourth capacitor

J1: first switch

J2: second switch

SA1: load switch

OP1: operational amplifier

CR1-CR6: Impedance

ADC: Analog to digital signal conversion circuit

LDO1: Low Dropout Voltage Regulator

Vin: voltage input terminal

Vout: voltage output terminal

RX: sense impedance

CC1: capacitance

FIG. 1 is a schematic diagram of a directional light control circuit according to an embodiment of the present invention.

FIG. 2 is another schematic diagram of the voltage stabilizing circuit in FIG. 1 .

FIG. 3A is another schematic diagram of the load detection circuit of FIG. 1 .

FIG. 3B is another schematic diagram of the load detection circuit of FIG. 1 .

The following is an illustration of the implementation of the "direction light control circuit" disclosed by the present invention through specific specific examples. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and various modifications and changes can be made to the details in this specification based on different viewpoints and applications without departing from the concept of the present invention. In addition, the drawings of the present invention are only for simple illustration, and are not drawn according to the actual size, which is stated in advance. The following embodiments will further describe the relevant technical content of the present invention in detail, but the disclosed content is not intended to limit the protection scope of the present invention. In addition, the term "or" used herein may include any one or a combination of more of the associated listed items depending on the actual situation.

In the following description, if the electronic components including two pins are installed horizontally, the The left side is the first end, and the right side is the second end. If it is set vertically, the top is the first end, and the bottom is the second end. For electronic components with more than three pins, the digital label of each pin shall prevail.

[first embodiment]

Referring to FIG. 1 , FIG. 2 , FIG. 3A and FIG. 3B , FIG. 1 is a schematic diagram of a direction light control circuit according to an embodiment of the present invention. FIG. 2 is another schematic diagram of the voltage stabilizing circuit in FIG. 1 . FIG. 3A is another schematic diagram of the load detection circuit of FIG. 1 . FIG. 3B is another schematic diagram of the load detection circuit of FIG. 1 .

Please refer to FIG. 1 , this embodiment provides a turn signal control circuit SYS. The direction light control circuit SYS includes a voltage stabilizing circuit 1, a control circuit 2, a voltage detection circuit 3, an output circuit 4, a differential amplifier circuit 5, a load detection circuit 6, a first switch J1 and a load switch SA1.

The voltage stabilizing circuit 1 is electrically connected to the control circuit. The voltage stabilizing circuit 1 is connected to an input voltage source (VCC) to receive an input voltage and convert the input voltage into a DC input voltage to the control circuit 2 .

The voltage detecting circuit 3 is electrically connected to the control circuit and the voltage stabilizing circuit. The output circuit 4 is electrically connected to the control circuit 2 , the voltage detection circuit 3 and the voltage stabilizing circuit 1 . The differential amplifier circuit 5 is electrically connected to the control circuit 2 , the output circuit 4 , the voltage detection circuit 3 and the voltage stabilization circuit 1 . The load detection circuit 6 is electrically connected to the control circuit 2 and the voltage stabilizing circuit 1 . The first switch J1 is electrically connected to the differential amplifier circuit 5 and the load detection circuit 6 . The load switch SA1 is connected to a light-emitting diode lamp load 8 , the load detection circuit 6 and the first switch J1 .

The voltage stabilizing circuit 1 includes a first diode D1 , a first impedance R1 , a first Zener diode Z1 and a first capacitor C1 . The first diode D1 includes a first end and a second end. The first Zener diode Z1 includes a first end and a second end. The first capacitor C1 includes a first terminal and a second terminal.

A first end of the first diode D1 is connected to the input voltage source VCC. A second end of the first diode D1 is connected to a first end of the first impedance R1. A second end of the first impedance R1 is connected to a first end of the first Zener diode Z1. The second end of the first Zener diode Z1 is connected to a ground potential. First A first end of the capacitor C1 is connected to a first end of the first Zener diode Z1. The second end of the first capacitor C1 is connected to the ground potential. The voltage stabilizing circuit 1 converts the input voltage of the input voltage source VCC into 5V for the control circuit 2 .

In other embodiments, as shown in FIG. 2 , the first Zener diode in the voltage stabilizing circuit 1 can be replaced by a low-dropout regulator LDO1 to provide a more stable input voltage. The low dropout voltage regulator LDO1 includes a voltage input terminal Vin, a voltage output terminal Vout and a ground terminal. Wherein, the second end of the first impedance R1 is connected to the voltage input end Vin. The voltage output terminal Vout is connected to the first terminal of the first capacitor C1 and the control circuit 2 .

The voltage detection circuit 3 includes a second impedance R2, a third impedance R3 and a second capacitor C2. The second impedance R2 includes a first end and a second end. The third impedance R3 includes a first end and a second end. The second capacitor C2 includes a first terminal and a second terminal. The first end of the second impedance R2 is electrically connected to the voltage stabilizing circuit 1 . The second end of the second impedance R2 is electrically connected to the first end of the third impedance R3. The second end of the third impedance R3 is connected to the ground potential. The first end of the second capacitor C2 is electrically connected to the second end of the second impedance R2 , the first end of the third impedance R3 and the control circuit 2 . The second end of the second capacitor C2 is electrically connected to the second end of the third impedance R3 and the control circuit 2 .

The voltage detection circuit 3 mainly provides a detection voltage of the input voltage source VCC to the control circuit 2 for judgment. Since the voltage of the input voltage source VCC varies under different load conditions, the control circuit 2 can judge the load status from the detection voltage provided by the voltage detection circuit 3 .

In addition, as shown in FIG. 3A , the voltage detection circuit 3A can be combined by an operational amplifier OP1 , a capacitor CC1 and impedances CR1 - CR4 to form a relatively fine voltage judgment circuit.

As shown in FIG. 3B , the voltage detection circuit 3B uses an analog-to-digital signal conversion circuit ADC with impedances CR5-CR6 to convert an analog voltage into a digital signal for voltage judgment.

The output circuit 4 includes a fourth impedance R4, a third capacitor C3, and a second diode D2, a third diode D3, a second switch J2, and a first switch element Q1.

The fourth impedance R4 includes a first end and a second end. The third capacitor C3 includes a first terminal and a second terminal. The second diode D2 includes a first end and a second end. The third diode D3 includes a first end and a second end. The second switch J2 includes a first terminal and a second terminal. The first switch element Q1 includes a first terminal, a second terminal and a third terminal.

A first end of the fourth impedance R4 is electrically connected to the control circuit 2 . The second end of the fourth impedance R4 is electrically connected to the first end of the third capacitor C3 and the second end of the first switching element Q1. The second end of the third capacitor C3 is electrically connected to the ground potential. The first end of the second diode ( D2 ) is electrically connected to the first end of the second impedance R2 and the voltage stabilizing circuit 1 .

The second end of the second diode D2 is electrically connected to the first end of the third diode D3 and the first end of the second switch J2. The second end of the third diode D3 is electrically connected to the second end of the second switch J2 and the first end of the first switch element Q1 . The third end of the first switch element Q1 is electrically connected to the ground potential. Wherein, the cathode (Cathode) of the third diode D3 is connected with the cathode (Cathode) of the second diode D2.

The differential amplifier circuit 5 includes a second switch element Q2, a third switch element Q3, a fourth switch element Q4, a fifth switch element Q5, a fifth impedance R5, a sixth impedance R6, and a seventh impedance R7 , an eighth impedance R8 , a ninth impedance R9 , a tenth impedance R10 , an eleventh impedance R11 , a sensing impedance RX, and a fourth capacitor C4 .

The fifth impedance R5 includes a first end and a second end. The sixth impedance R6 includes a first end and a second end. The seventh impedance R7 includes a first end and a second end. The eighth impedance R8 includes a first end and a second end. The ninth impedance R9 includes a first end and a second end. The tenth impedance R10 includes a first end and a second end. The eleventh impedance R11 includes a first end and a second end. The sensing impedance RX includes a first end and a second end. The second switch element Q2 includes a first terminal, a second terminal and a third terminal. The third switching element Q3 includes a first terminal, a second terminal and a third end. The fourth switch element Q4 includes a first terminal, a second terminal and a third terminal. The fifth switch element Q5 includes a first terminal, a second terminal and a third terminal. The first end of the sensing impedance RX is electrically connected to the first end of the fifth impedance R5 , the first end of the second diode D2 , the first end of the second impedance R2 and the voltage stabilizing circuit 1 . The second terminal of the sensing resistor RX is electrically connected to the first terminal of the third switching element Q3. The second end of the fifth impedance R5 is electrically connected to the first end of the second switch element Q2. The second end of the second switch element Q2 is electrically connected to the second end of the third switch element Q3. The second end of the third switch element Q3 is electrically connected to the second end of the third switch element Q3 and the first end of the sixth impedance R6. The second end of the sixth impedance R6 is electrically connected to the ground potential. The third end of the second switch element Q2 is electrically connected to the first end of the fourth switch element Q4. The first end of the fourth switch element Q4 is electrically connected to the second end of the fourth switch element Q4. The third end of the fourth switch element Q4 is electrically connected to the first end of the seventh impedance R7. The second end of the seventh impedance R7 is electrically connected to the second end of the tenth impedance R10 and the first end of the ninth impedance R9. A first end of the third switch element Q3 is electrically connected to a second end of the sensing resistor RX. The third end of the third switching element Q3 is electrically connected to the first end of the fifth switching element Q5. The second end of the fifth switch element Q5 is electrically connected to the second end of the fourth switch element Q4. The third end of the fifth switch element Q5 is electrically connected to the first end of the eighth impedance R8. The second end of the eighth impedance R8 is electrically connected to the second end of the ninth impedance R9 and the ground potential. The first end of the tenth impedance R10 is electrically connected to the first end of the eleventh impedance R11 , the first end of the third capacitor C3 and the control circuit 2 . The second end of the eleventh impedance R11 and the second end of the third capacitor C3 are electrically connected to the ground potential.

The load detection circuit 6 includes a twelfth impedance R12 , a thirteenth impedance R13 , a fourteenth impedance R14 and a fourth diode D4 . The twelfth impedance R12 includes a first end and a second end. The thirteenth impedance R13 includes a first end and a second end. The fourteenth impedance R14 includes a first end and a second end. The fourth diode D4 includes a first end and a second end.

The first end of the twelfth impedance R12 is electrically connected to the voltage stabilizing circuit 1 . The second end of the twelfth impedance R12 is electrically connected to the first end of the thirteenth impedance R13 and the first end of the fourth diode D4. fourth The second terminal of the first switch J1 of the diode D4 and the load switch SA1. The second end of the thirteenth impedance R13 is electrically connected to the first end of the fourteenth impedance R14 and the control circuit 2 . The second end of the fourteenth impedance R14 is electrically connected to the ground potential.

The first switch J1 and the second switch J2 are single-pole switches. The load switch SA1 can be a double-pole switch or a three-pole switch. The first switch element Q1, the second switch element Q2, the third switch element Q3, the fourth switch element Q4 and the fifth switch element Q5 are respectively a metal oxide semiconductor field effect transistor (MOSFET) or a bipolar transistor (BJT).

When the first switching element Q1, the second switching element Q2, the third switching element Q3, the fourth switching element Q4 and the fifth switching element Q5 are respectively bipolar transistors, the first switching element Q1, the fourth switching element Q4 And the fifth switching element Q5 is an NPN type bipolar transistor, and the second switching element Q2 and the third switching element Q3 are respectively a PNP bipolar transistor. Wherein, the first ends of the first switching element Q1, the second switching element Q2, and the third switching element Q3 are collectors. The second terminals of the first switching element Q1, the second switching element Q2 and the third switching element Q3 are bases. The third terminals of the first switching element Q1, the second switching element Q2 and the third switching element Q3 are emitters. The first ends of the second switching element Q2 and the third switching element Q3 are emitters, the second ends of the second switching element Q2 and the third switching element Q3 are bases, and the second switching element Q2 and the third switching element Q3 The third terminal is the collector.

When the first switch element Q1, the second switch element Q2, the third switch element Q3, the fourth switch element Q4 and the fifth switch element Q5 are respectively a metal oxide semiconductor field effect transistor, the first switch element Q1, The fourth switch element Q4 and the fifth switch element Q5 are respectively an N-type MOSFET, and the second switch element Q2 and the third switch element Q3 are respectively a P-type MOSFET. Wherein, the first terminals of the first switch element Q1 , the second switch element Q2 and the third switch element Q3 are sources. The second terminals of the first switching element Q1 , the second switching element Q2 and the third switching element Q3 are gates. The first switching element Q1, the second switching element Q2, The third terminal of the third switching element Q3 is a drain. The first ends of the second switching element Q2 and the third switching element Q3 are drains, the second ends of the second switching element Q2 and the third switching element Q3 are gates, and the second switching element Q2 and the third switching element Q3 The third terminal is the source.

When the first switch J1 and the second switch J2 are short-circuited and connected, the second switch J2 of the output circuit 4 is closed, and the first switch element Q1 is turned on, so that the voltage of the output voltage source VCC is transmitted through the differential amplifier 5 and the first switch J1 , waiting for output. In this embodiment, the first switch J1 and the second switch J2 can operate synchronously with the power system of the vehicle, so that the direction light control circuit SYS is in a standby state. In this embodiment, the first switch J1 and the second switch J2 are set together. The first switch J1 and the second switch J2 can be jointly configured as a relay device as a control switch.

When the load voltage SA1 is switched to the LED lamp load 8 , the input voltage source VCC will output power, which flows through the sensing impedance RX of the differential amplifier circuit 5 , the first switch J1 and the LED lamp load 8 .

Since the current flowing through the light-emitting diode lamp load 8 is not a large current, the direction light control circuit SYS utilizes the sensing impedance RX of the differential amplifier circuit 5 to detect the voltage, and through the amplification of the differential amplifier circuit 5, the tenth The voltage division of the impedance R10 and the eleventh impedance R11 transmits the voltage of the detected load current back to the control circuit 2 for accurate load judgment. In addition, the differential amplifier circuit 5 can also effectively detect whether the current flowing through the first switch J1 and the load switch SA1 is a leakage current. In general, the leakage current is usually quite small (eg a few mA). Even if there is a leakage current flowing through the sensing impedance RX, the voltage caused by the leakage current is amplified by the differential amplifier 5 and sent back to the detection voltage of the control circuit 2 , which will not cause misjudgment by the control circuit 2 . Therefore, the directional light control circuit SYS of the present invention can effectively avoid the misoperation of the leakage current.

In addition, when the load detection circuit 6 does not connect the load switch SA1 to the light-emitting diode lamp load 8 (the control circuit 2 is not in a load situation), the input voltage of the input voltage source VCC can pass through the twelfth impedance R12, the second The thirteenth impedance R13 and the fourteenth impedance R14 are sent back to the control circuit 2. Since no current flows to the load through the first diode D1 at this time, the detection voltage transmitted to the control circuit 2 will be higher.

When the load switch SA1 is connected to the LED lamp load 8 , due to the load effect, the detection voltage sent back from the load detection circuit 6 to the control circuit 2 will be relatively low.

In addition, the directional light control circuit SYS of this embodiment can be used to control two LED lamp loads 8 . That is, the two light-emitting diode lamp loads 8 respectively manage the display of the direction lights on the left and right sides.

In this embodiment, each LED lamp load 8 includes at least two LED lamps 8-1, 8-2, when one of the LED lamps of the LED lamp load 8 is damaged , the load current flowing through the light emitting diode lamp load 8 will be smaller. At this time, the direction lamp control circuit SYS can be adjusted by the change of the load current.

In this embodiment, the detection of the load state can be made through the voltage provided by the voltage detection circuit 3 , the differential amplifier circuit 5 and the load detection circuit 6 for accurate judgment of the load state, which can effectively avoid misjudgment caused by wrong current.

In this embodiment, the control circuit 2 is a programmable chip, including 8 pins. In other embodiments, the control circuit 2 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a graphics processing unit (GPU), or a microprocessor (MCU).

[Advantageous Effects of Embodiment]

One of the beneficial effects of the present invention is that the directional light control circuit provided by the present invention can provide an output with a small load current in response to the load. It is also possible to judge the load status through the detection voltage of multiple circuits, and it can effectively avoid malfunction caused by leakage current.

The content disclosed above is only a preferred feasible embodiment of the present invention, and does not therefore limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made by using the description and drawings of the present invention are included in the application of the present invention. within the scope of the patent.

SYS: turn signal control circuit 1: Slider 2: Control circuit 3: Voltage detection circuit 4: Output circuit 5: Differential amplifier circuit 6: Load detection circuit 8: Light-emitting diode lamp load D1: the first diode D2: second diode D3: The third diode D4: The fourth diode R1: first impedance R2: second impedance R3: the third impedance R4: the fourth impedance R5: fifth impedance R6: sixth impedance R7: seventh impedance R8: Eighth impedance R9: ninth impedance R10: Tenth impedance R11: Eleventh impedance R12: Twelfth impedance R13: Thirteenth impedance R14: Fourteenth impedance Z1: The first Zener diode Q1: The first switching element Q2: Second switching element Q3: The third switching element Q4: The fourth switching element Q5: Fifth switching element 8-1, 8-2: Light-emitting diode lamps C1: the first capacitor C2: second capacitor C3: the third capacitor C4: the fourth capacitor J1: first switch J2: second switch SA1: load switch RX: sense impedance

Claims (10)

A directional light control circuit, comprising: a control circuit; a voltage stabilizing circuit electrically connected to the control circuit, the voltage stabilizing circuit connected to an input voltage source to receive an input voltage, and convert the input voltage to a direct current Input voltage to the control circuit; a voltage detection circuit electrically connected to the control circuit and the voltage stabilization circuit; an output circuit electrically connected to the control circuit, the voltage detection circuit and the voltage stabilization circuit ; a differential amplifier circuit, electrically connected to the control circuit, the output circuit, the voltage detection circuit and the voltage stabilization circuit; a load detection circuit, electrically connected to the control circuit and the voltage stabilization circuit ; a first switch electrically connected to the differential amplifier circuit and the load detection circuit; and a load switch connected to the load detection circuit and the first switch. The directional light control circuit according to claim 1, wherein the voltage stabilizing circuit includes a first diode, a first impedance, a first Zener diode and a first capacitor, the first The diode includes a first end and a second end, the first impedance includes a first end and a second end, the first Zener diode includes a first end and a second end, The first capacitor includes a first terminal and a second terminal, the first terminal of the first diode is connected to the input voltage source, and the second terminal of the first diode is connected to The first end of the first impedance and the second end of the first impedance are connected to the first end of the first Zener diode, and the first Zener diode The second end of the first capacitor is connected to a ground potential, the first end of the first capacitor is connected to the first end of the first Zener diode, and the second end of the first capacitor Connect the ground potential. The directional light control circuit according to claim 1, wherein the voltage detection circuit includes a second impedance, a third impedance, and a second capacitor, and the second impedance includes a first end and a second end , the third impedance includes a first end and a second end, the second capacitor includes a first end and a second end, the first end of the second impedance is electrically connected to the voltage stabilizing circuit , the second end of the second impedance is electrically connected to the first end of the third impedance, the second end of the third impedance is connected to a ground potential, and the second capacitor of the second capacitor The first end is electrically connected to the second end of the second impedance, the first end of the third impedance and the control circuit, and the second end of the second capacitor is electrically connected to The second end of the third impedance and the control circuit. The directional light control circuit according to claim 3, wherein the output circuit includes a fourth impedance, a third capacitor, a second diode, a third diode, a second switch and a first A switch element, the fourth impedance includes a first end and a second end, the third capacitor includes a first end and a second end, and the second diode includes a first end and a second end The second end, the third diode includes a first end and a second end, the second switch includes a first end and a second end, the first switch element includes a first end, A second end and a third end, the first end of the fourth impedance is electrically connected to the control circuit, the second end of the fourth impedance is electrically connected to the third capacitor The first end and the second end of the first switching element, the second end of the third capacitor is electrically connected to the ground potential, the first end of the second diode electrically connecting the first end of the second impedance and the voltage stabilizing circuit, the second end of the second diode is electrically connected to the first end of the third diode and the first end of the second switch, the second end of the third diode is electrically connected to the second end of the second switch and the first end of the first switch element terminal, the first switching element The third terminal is electrically connected to the ground potential. The direction light control circuit according to claim 4, wherein the differential amplifier circuit includes a second switching element, a third switching element, a fourth switching element, a fifth switching element, a fifth impedance, a A sixth impedance, a seventh impedance, an eighth impedance, a ninth impedance, a tenth impedance, an eleventh impedance, a sensing impedance, and a fourth capacitance; wherein, the fifth impedance includes a first One end and a second end, the sixth impedance includes a first end and a second end, the seventh impedance includes a first end and a second end, the eighth impedance includes a first end and a second end, the ninth impedance includes a first end and a second end, the tenth impedance includes a first end and a second end, and the eleventh impedance includes a first end and a second end A second end, the sensing impedance includes a first end and a second end, the second switching element includes a first end, a second end and a third end, the third switching element includes A first end, a second end and a third end, the second switching element includes a first end, a second end and a third end, the second switching element includes a first end, a a second end and a third end; wherein, the first end of the sensing impedance is electrically connected to the first end of the fifth impedance and the first end of the second diode , the first end of the second impedance and the voltage stabilizing circuit; wherein, the second end of the sensing impedance is electrically connected to the first end of the third switching element, and the fifth The second end of the impedance is electrically connected to the first end of the second switch element, and the second end of the second switch element is electrically connected to the second end of the third switch element , the second end of the third switch element is electrically connected to the second end of the third switch element and the first end of the sixth impedance, the first end of the sixth impedance Two ends are electrically connected to the ground potential; wherein, the third end of the second switch element is electrically connected to the fourth switch the first end of the switching element, the first end of the fourth switching element is electrically connected to the second end of the fourth switching element, and the third end of the fourth switching element is electrically is electrically connected to the first end of the seventh impedance, and the second end of the seventh impedance is electrically connected to the second end of the tenth impedance and the first end of the ninth impedance end; wherein, the first end of the third switching element is electrically connected to the second end of the sensing impedance, and the third end of the third switching element is electrically connected to the fifth The first end of the switch element, the second end of the fifth switch element is electrically connected to the second end of the fourth switch element, and the third end of the fifth switch element is electrically connected to the second end of the fifth switch element. is electrically connected to the first end of the eighth impedance, and the second end of the eighth impedance is electrically connected to the second end of the ninth impedance and the ground potential; wherein, the first The first end of the tenth impedance is electrically connected to the first end of the eleventh impedance, the first end of the third capacitor and the control circuit, and the first end of the eleventh impedance The second terminal and the second terminal of the third capacitor are electrically connected to the ground potential. The directional light control circuit according to claim 1, wherein the load detection circuit includes a twelfth impedance, a thirteenth impedance, a fourteenth impedance and a fourth diode, and the tenth The second impedance includes a first end and a second end, the thirteenth impedance includes a first end and a second end, the fourteenth impedance includes a first end and a second end, and the thirteenth impedance includes a first end and a second end. The four diodes include a first end and a second end, the first end of the twelfth impedance is electrically connected to the voltage stabilizing circuit, and the second end of the twelfth impedance is electrically connected connecting the first end of the thirteenth impedance and the first end of the fourth diode, the second end of the first switch of the fourth diode and the a load switch, the second end of the thirteenth impedance is electrically connected to the first end of the fourteenth impedance and the control circuit, the fourteenth impedance The second end is electrically connected to a ground potential. The directional light control circuit according to claim 1, wherein the load switch is used to connect a light-emitting diode lamp load, and the light-emitting diode lamp load includes two light-emitting diode lamps. The directional light control circuit according to claim 4, wherein the first switch and the second switch are a single-pole switch, and the load switch (SA1) is a double-pole switch or a three-pole switch. The directional light control circuit according to claim 5, wherein the first switch element, the second switch element, the third switch element, the fourth switch element and the fifth switch element are respectively A metal oxide field effect transistor or a bipolar transistor. The directional light control circuit according to claim 9, wherein when the first switch element, the second switch element, the third switch element, the fourth switch element and the fifth switch element are respectively When it is a bipolar transistor, the first switching element, the fourth switching element and the fifth switching element are respectively an NPN type bipolar transistor, and the second switching element and the third switching element are respectively a PNP bipolar transistor.

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