A driving circuit and control method of a touch-adjustable light lamp

Abstract

The application discloses a driving circuit and a control method of a touch-adjustable light lamp, the circuit comprising a rectification filtering unit M1, a driving control unit M2 and a starting unit M3; the output ends of the rectification filtering unit M1 are connected with the driving control unit M2 and the starting unit M3 respectively; the driving control unit M2 and the starting unit M3 are electrically connected; the driving control unit M2 comprises a control chip U2 and a power supply module S1; the starting unit M3 comprises a starting chip U1 and a power supply module S2; the power supply module S1 is used for supplying power to the control chip U2 when the driving circuit is in a standby-off mode or a touch detection mode, and the power supply module S2 is used for supplying power to the control chip U2 when the driving circuit is in a light-on mode. The driving circuit can realize multi-mode power supply by using general simple devices, takes into account the loss of the driving circuit in three modes, reduces the cost of the driving circuit, and effectively solves the problems of large standby loss and high cost of the driving circuit.

Description

Technical Field

[0001] This invention relates to the field of driving circuit technology, and in particular to a driving circuit and control method for a touch-sensitive dimmable lamp. Background Technology

[0002] Existing touch-sensitive dimmable lamps generally use PWM waves for dimming. Therefore, the lamp's driving circuit needs a control chip that can generate PWM signals and detect touch signals. Furthermore, the driving circuit of touch-sensitive dimmable lamps typically has three working states: 1. Standby mode; 2. Touch detection mode; 3. Lighting mode. The power consumption of the control chip is different in these three working states, that is, the required power supply voltage is different.

[0003] In existing technologies, a dedicated high-voltage to low-voltage power supply chip is typically configured in the driver circuit, such as... Figure 2 The power supply chip U3 is dedicated to powering the control chip U2. However, using a dedicated power supply chip results in higher power consumption for the control chip in standby mode, meaning the standby power loss of the entire drive circuit is significant, and the circuit cost is also high. Therefore, improvements are needed. Summary of the Invention

[0004] This application addresses the aforementioned problems and technical needs by proposing a driving circuit and control method for a touch-sensitive dimmable lamp, the technical solution of which is as follows:

[0005] In a first aspect, this application provides a driving circuit for a touch-sensitive dimmable lamp. The circuit includes a rectifier and filter unit M1, a drive control unit M2, and a start-up unit M3; the output of the rectifier and filter unit M1 is connected to both the drive control unit M2 and the start-up unit M3; the drive control unit M2 and the start-up unit M3 are electrically connected; the power supply control unit M2 includes a control chip U2 and a power supply module S1; the start-up unit M3 includes a start-up chip U1 and a power supply module S2; the power supply module S1 supplies power to the control chip U2 when the drive circuit is in standby off-light mode or touch detection mode, and the power supply module S2 supplies power to the control chip U2 when the drive circuit is in on-light mode.

[0006] A further technical solution is as follows: the power supply module S1 includes a MOSFET Q1 and resistors R3, R7, R8, R11, R17, and R19; one end of resistors R19 and R11 is electrically connected to the output terminal of the rectifier and filter unit M1; the other end of resistors R19 and R11 and one end of resistor R17 are electrically connected to one end of resistor R3; the other end of resistors R3 and R17 and one end of resistor R7 are electrically connected to the drain of MOSFET Q1; the other end of resistor R7 is electrically connected to one end of resistor R8; the other end of resistor R8 and the source of MOSFET Q1 are electrically connected to the VDD terminal of the control chip U2; the PB1 terminal of the control chip U2 is electrically connected to the gate of MOSFET Q1, and is used to control the on / off state of MOSFET Q1.

[0007] The further technical solution is as follows: the power supply module S2 includes a transformer L2, a diode D1, and a resistor R15; one end of the main winding of the transformer L2 is electrically connected to the output terminal of the rectifier and filter unit M1, and the other end of the main winding of the transformer L2 is electrically connected to the DRAIN terminal of the starter chip U1; one end of the secondary winding of the transformer L2 is electrically connected to the positive terminal of the diode D1, the negative terminal of the diode D1 is electrically connected to one end of the resistor R15, the other end of the resistor R15 is electrically connected to the VDD terminal of the control chip U2, and the other end of the secondary winding of the transformer L2 is grounded.

[0008] A further technical solution is that the power supply module S2 also includes a Zener diode D2; the positive terminal of the Zener diode D2 is electrically connected to the VDD terminal of the control chip U2 via capacitor C6, and the negative terminal of the Zener diode D2 is electrically connected to the other end of resistor R9 and resistor R15.

[0009] A further technical solution is that the starting unit M3 also includes a signal output terminal and an electrolytic capacitor CE2; the signal output terminal is electrically connected to the lamp load; the signal output terminal includes a positive output terminal D+ and a negative output terminal D-; the positive output terminal D+ and the positive terminal of the electrolytic capacitor CE2 are both electrically connected to the output terminal of the rectifier and filter unit M1; the negative output terminal D- and the negative terminal of the electrolytic capacitor CE2 are both electrically connected to one end of the main winding of the transformer L2.

[0010] A further technical solution is as follows: the rectifier filter unit M1 includes a fuse F1, a rectifier bridge B1, an inductor L1, a resistor R1, and electrolytic capacitors CE1 and CE3; the first input terminal of the rectifier bridge B1 is electrically connected to the neutral terminal N, and the second input terminal of the rectifier bridge B1 is electrically connected to the live terminal L via the fuse F1; one end of the inductor L1, one end of the resistor R1, and the positive terminal of the electrolytic capacitor CE1 are all electrically connected to the first output terminal of the rectifier bridge B1; the other end of the inductor L1 and the other end of the resistor R1 are all electrically connected to the positive terminal of the electrolytic capacitor EC3; the second output terminal of the rectifier bridge B1, the negative terminal of the electrolytic capacitor CE1, and the negative terminal of the electrolytic capacitor EC3 are all grounded; the first output terminal of the rectifier bridge B1 is the output terminal of the rectifier filter unit M1.

[0011] A further technical solution is that the drive control unit M2 also includes a touch module Touch1, which is electrically connected to the PB0 terminal of the control chip U2; the touch module Touch1 is used to send the detected touch signal to the control chip U2.

[0012] A further technical solution is that the PB2 terminal of the control chip U2 and the PWM terminal of the starter chip U1 are electrically connected; the control chip U2 transmits the generated PWM signal to the PWM terminal of the starter chip U1 through the PB2 terminal, which is used to drive the starter chip U1 to control the brightness of the lamp.

[0013] Secondly, this application provides a driving control method for a touch-sensitive dimmable desk lamp, which is implemented based on any of the aforementioned driving circuits, and includes:

[0014] The mains power is converted into DC power by the rectifier and filter unit M1 and output to the drive control unit M2 and the starter unit M3.

[0015] When the driving circuit is in standby mode, the MOSFET Q1 in the power supply module S1 is turned off. The DC voltage output by the rectifier and filter unit M1 is divided by resistors R19, R11, R3, R17, R7 and R8 to supply power to the control chip U2.

[0016] When the control chip U2 receives the touch signal sent by the touch module Touch1, the driving circuit enters the touch detection mode. The control chip U2 turns on the MOSFET Q1, and the DC voltage output by the rectifier filter unit M1 is divided by resistors R19, R11, R3, and R17 and then powered by the MOSFET Q1.

[0017] If the touch signal detected by the control chip U2 is invalid, the control chip U2 will turn off the MOSFET Q1, and the working state of the drive circuit will return to the standby mode with the lights off.

[0018] If the touch signal detected by the control chip U2 is a valid signal, the control chip U2 will drive the start chip U1 and turn off the MOSFET Q1, so that the working state of the drive circuit enters the light-up mode.

[0019] A further technical solution is that when the driving circuit is in the lighting mode, the DC voltage output by the rectifier and filter unit M1 is coupled by the transformer L2 and then supplied to the control chip U2 through the diode D1 and resistor R15 in the power supply module S2.

[0020] The beneficial technical effects of this invention are:

[0021] The driving circuit disclosed in this invention can achieve multi-mode power supply using general and simple components, taking into account the losses of the driving circuit in the three modes, and reducing the cost of the driving circuit, effectively solving the drawbacks of high standby power loss and high cost of the driving circuit. Attached Figure Description

[0022] Figure 1 This is the driving circuit diagram of the present invention.

[0023] Figure 2 This is a driving circuit diagram of existing technology. Detailed Implementation

[0024] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0025] In one embodiment, a driving circuit for a touch-sensitive dimmable lamp is provided, such as... Figure 1 As shown, the circuit includes a rectifier and filter unit M1, a drive control unit M2, and a start-up unit M3; the output terminals of the rectifier and filter unit M1 are connected to the drive control unit M2 and the start-up unit M3 respectively; the drive control unit M2 and the start-up unit M3 are electrically connected; the power supply control unit M2 includes a control chip U2 and a power supply module S1; the start-up unit M3 includes a start-up chip U1 and a power supply module S2; the power supply module S1 is used to supply power to the control chip U2 when the drive circuit is in standby mode or touch detection mode, and the power supply module S2 is used to supply power to the control chip U2 when the drive circuit is in light-on mode.

[0026] Optionally, the power supply module S1 includes a MOSFET Q1 and resistors R3, R7, R8, R11, R17, and R19. One end of resistors R19 and R11 is electrically connected to the output terminal of the rectifier and filter unit M1. The other ends of resistors R19 and R11 and one end of resistor R17 are electrically connected to one end of resistor R3. The other ends of resistors R3 and R17 and one end of resistor R7 are electrically connected to the drain of MOSFET Q1. The other end of resistor R7 is electrically connected to one end of resistor R8. The other end of resistor R8 and the source of MOSFET Q1 are electrically connected to the VDD terminal of the control chip U2. The PB1 terminal of the control chip U2 is electrically connected to the gate of MOSFET Q1 and is used to control the on / off state of MOSFET Q1.

[0027] Specifically, resistors R19 and R11 are connected in parallel, and R3 and R17 are connected in parallel. These two sets of parallel resistors are then connected in series with resistors R7 and R8. The series resistors R7 and R8 are connected in parallel with MOSFET Q1.

[0028] Optionally, the drive control unit M2 also includes a touch module Touch1, which is electrically connected to the PB0 terminal of the control chip U2; the touch module Touch1 is used to send the detected touch signal to the control chip U2.

[0029] Optionally, the PB2 terminal of the control chip U2 and the PWM terminal of the start-up chip U1 are electrically connected; the control chip U2 transmits the generated PWM signal to the PWM terminal of the start-up chip U1 through the PB2 terminal, which is used to drive the start-up chip U1 to control the brightness of the lamp.

[0030] Specifically, the drive control unit M2 in this embodiment also includes capacitors C6 and C7 and resistors R12 and R13; one end of capacitor C6 is electrically connected to the VDD terminal of control chip U2, one end of capacitor C7 is electrically connected to the PB3 / RSTB terminal of control chip U2, and the other ends of capacitors C6 and C7 are both grounded; the gate of MOSFET Q1 is connected to the PB1 terminal of control chip U2 via resistor R12; the touch module Touch1 is electrically connected to the PB0 terminal of control chip U2 via resistor R13.

[0031] Optionally, the power supply module S2 includes a transformer L2, a diode D1, and a resistor R15; one end of the main winding of the transformer L2 is electrically connected to the output terminal of the rectifier and filter unit M1, and the other end of the main winding of the transformer L2 is electrically connected to the DRAIN terminal of the starter chip U1; one end of the secondary winding of the transformer L2 is electrically connected to the positive terminal of the diode D1, the negative terminal of the diode D1 is electrically connected to one end of the resistor R15, the other end of the resistor R15 is electrically connected to the VDD terminal of the control chip U2, and the other end of the secondary winding of the transformer L2 is grounded.

[0032] Optionally, the power supply module S2 also includes a Zener diode D2; the positive terminal of the Zener diode D2 is electrically connected to the VDD terminal of the control chip U2 via capacitor C6, and the negative terminal of the Zener diode D2 is electrically connected to the other end of resistor R9 and resistor R15.

[0033] Optionally, the starting unit M3 further includes a signal output terminal and an electrolytic capacitor CE3; the signal output terminal is electrically connected to the lamp load; the signal output terminal includes a positive output terminal D+ and a negative output terminal D-; the positive output terminal D+ and the positive terminal of the electrolytic capacitor CE3 are both electrically connected to the output terminal of the rectifier and filter unit M1; the negative output terminal D- and the negative terminal of the electrolytic capacitor CE3 are both electrically connected to one end of the main winding of the transformer L2.

[0034] Specifically, in this embodiment, the startup unit M3 further includes an electrolytic capacitor CE4, a capacitor C2, and resistors R2, R4, R5, R6, and R10; the positive terminal of the electrolytic capacitor CE4 is electrically connected to the negative terminal of the Zener diode D2, and the negative terminal of the electrolytic capacitor CE4 is grounded; one end of the capacitor C2 is electrically connected to the negative output terminal D-, and the other end is grounded; one end of the resistor R2 is electrically connected to the ROVP terminal of the startup chip U1, and the other end is grounded; one end of the resistor R10 is electrically connected to the positive output terminal D+, and the other end is electrically connected to the negative output terminal D-; one end of the resistor R4 is electrically connected to the PWM terminal of the startup chip U1, and the other end is grounded; one end of each of the resistors R5 and R6 is electrically connected to the CS terminal of the startup chip U1, and the other end of each of the resistors R5 and R6 is grounded.

[0035] Specifically, the working principle of the driving circuit in this embodiment is as follows:

[0036] When the lights are off, the drive circuit is in standby mode, and the average current consumption of the control chip U2 is approximately 50uA. At this time, the DC voltage output from the rectifier and filter unit M1 is divided by resistors R19, R11, R3, R17, R7, and R8 in the power supply module S1 to supply power to the control chip U2. The resistance values ​​of R7 and R8 can be designed to be quite large, as long as they meet the power supply current requirements of the control chip U2; this will significantly reduce the standby power consumption. In this embodiment, it is preferable that the resistance values ​​of R19, R11, R3, and R17 are all 82kΩ, and the resistance value of R7 and R8 is 1.2MΩ. The standby power consumption is then... It is approximately 39mW.

[0037] When an object touches the Touch module Touch1, Touch1 sends a touch detection signal to the control chip U2. At this time, the drive circuit enters the "touch detection mode". In this mode, the control chip U2 requires a supply current of about 1mA. Since the startup chip U1 of the back-end startup unit M3 is not working, the transformer L2 will also have no mutual inductance voltage, and the supply current in the above-mentioned standby light-off mode is insufficient. At this time, the control chip U2 will turn on the MOSFET Q1, and then the DC voltage output by the rectifier and filter unit M1 is divided by resistors R19, R11, R3, and R17 and then supplied to the control chip U2 through the MOSFET Q1.

[0038] If the touch signal detected by the control chip U2 is valid, it will drive the startup chip U1 at the back end to turn on the lamp load. At this time, the drive circuit enters the "lighting mode" and the control chip U2 turns off the MOSFET Q1 to reduce circuit loss. If the control chip U2 does not detect a valid touch signal, it will immediately turn off the MOSFET Q1 to make the drive circuit re-enter the "standby light-off mode".

[0039] In the lighting mode, the transformer L2 in the power supply module S2 transforms the DC voltage output by the rectifier and filter unit M1, and generates a voltage of about 8V through the coupling of the secondary winding and the main winding. After passing through diode D1, resistor R15, and being regulated by Zener diode D2, the voltage is supplied to the control chip U2. This power supply method is stable and reliable.

[0040] Preferably, in this embodiment, the power supply chip U2 is model HS16F321, and the signal for starting the chip U1 is BP2881B.

[0041] Optionally, the rectifier-filter unit M1 includes a fuse F1, a rectifier bridge B1, an inductor L1, a resistor R1, and electrolytic capacitors CE1 and CE3. The first input terminal of the rectifier bridge B1 is electrically connected to the neutral terminal N, and the second input terminal of the rectifier bridge B1 is electrically connected to the live terminal L via the fuse F1. One end of the inductor L1, one end of the resistor R1, and the positive terminal of the electrolytic capacitor CE1 are all electrically connected to the first output terminal of the rectifier bridge B1. The other end of the inductor L1 and the other end of the resistor R1 are all electrically connected to the positive terminal of the electrolytic capacitor EC3. The second output terminal of the rectifier bridge B1, the negative terminal of the electrolytic capacitor CE1, and the negative terminal of the electrolytic capacitor EC3 are all grounded. The first output terminal of the rectifier bridge B1 is the output terminal of the rectifier-filter unit M1.

[0042] In another embodiment, a driving control method for a touch-sensitive dimmable desk lamp is provided, which is implemented based on the driving circuit described in any of the above embodiments. The method specifically includes:

[0043] The mains power is converted into DC power by the rectifier and filter unit M1 and output to the drive control unit M2 and the starter unit M3.

[0044] When the driving circuit is in standby mode, the MOSFET Q1 in the power supply module S1 is turned off. The DC voltage output by the rectifier and filter unit M1 is divided by resistors R19, R11, R3, R17, R7 and R8 to supply power to the control chip U2.

[0045] When the control chip U2 receives the touch signal sent by the touch module Touch1, the driving circuit enters the touch detection mode. The control chip U2 turns on the MOSFET Q1, and the DC voltage output by the rectifier filter unit M1 is divided by resistors R19, R11, R3, and R17 and then powered by the MOSFET Q1.

[0046] If the touch signal detected by the control chip U2 is invalid, the control chip U2 will turn off the MOSFET Q1, and the working state of the drive circuit will return to the standby mode with the lights off.

[0047] If the touch signal detected by the control chip U2 is a valid signal, the control chip U2 will drive the start chip U1 and turn off the MOSFET Q1, so that the working state of the drive circuit enters the light-up mode.

[0048] Optionally, when the driving circuit is in the lighting mode, the DC voltage output by the rectifier and filter unit M1 is coupled through transformer L2 and then supplied to the control chip U2 via diode D1 and resistor R15 in the power supply module S2.

[0049] The driving circuit of the touch-sensitive dimmable lamp of the present invention achieves multi-mode power supply by using simple components, taking into account the loss of the driving circuit in three modes. In particular, the loss in the standby off mode is reduced from 400mW to 39mW, a reduction of 10 times, effectively reducing energy consumption. In the on mode, a transformer is used for power supply, which effectively improves efficiency. Furthermore, by reducing the power supply chip dedicated to powering the control chip and the matching color ring inductor, the cost of the driving circuit is effectively reduced.

[0050] The above descriptions are merely preferred embodiments of this application, and the present invention is not limited to the above embodiments. It is understood that other improvements and variations directly derived or conceived by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included within the protection scope of the present invention.

Claims

1. A driving circuit of a touch dimmable light fixture, characterized in that, The drive circuit comprises a rectification filter unit M1, a drive control unit M2 and a starting unit M3; output ends of the rectification filter unit M1 are connected to the drive control unit M2 and the starting unit M3 respectively; the drive control unit M2 and the starting unit M3 are electrically connected; the drive control unit M2 comprises a control chip U2 and a power supply module S1; the starting unit M3 comprises a starting chip U1 and a power supply module S2; the power supply module S1 is used for supplying power to the control chip U2 when the drive circuit is in a standby light-off mode or a touch detection mode, and the power supply module S2 is used for supplying power to the control chip U2 when the drive circuit is in a light-on mode; The drive control unit M2 further comprises a touch module Touch1, and the touch module Touch1 and a PB0 end of the control chip U2 are electrically connected; the touch module Touch1 is used for sending a detected touch signal to the control chip U2. The power supply module S1 comprises MOS tubes Q1 and resistors R3, R7, R8, R11, R17 and R19; resistors R19 and R11 are connected in parallel, resistors R3 and R17 are connected in parallel, and the two groups of parallel resistors are connected in series with resistors R7 and R8; the series connection of resistors R7 and R8 and the MOS tube Q1 are connected in parallel; a PB1 end of the control chip U2 and a gate of the MOS tube Q1 are electrically connected, and are used for controlling on-off of the MOS tube Q1. The power supply module S2 comprises a transformer L2, a diode D1 and a resistor R15; one end of a main winding of the transformer L2 is electrically connected to an output end of the rectification filter unit M1, and the other end of the main winding of the transformer L2 is electrically connected to a DRAIN end of the starting chip U1; one end of a secondary winding of the transformer L2 is electrically connected to a positive electrode of the diode D1, a negative electrode of the diode D1 is electrically connected to one end of the resistor R15, the other end of the resistor R15 is electrically connected to a VDD end of the control chip U2, and the other end of the secondary winding of the transformer L2 is grounded.

2. The drive circuit according to claim 1, characterized by The power supply module S1 comprises MOS tubes Q1 and resistors R3, R7, R8, R11, R17 and R19; one end of each of the resistors R19 and R11 is electrically connected to an output end of the rectification filter unit M1, the other end of each of the resistors R19 and R11 and one end of the resistor R17 are electrically connected to one end of the resistor R3, the other end of each of the resistors R3 and R17 and one end of the resistor R7 are electrically connected to a drain of the MOS tube Q1, the other end of the resistor R7 is electrically connected to one end of the resistor R8, the other end of the resistor R8 and a source of the MOS tube Q1 are electrically connected to a VDD end of the control chip U2; a PB1 end of the control chip U2 and a gate of the MOS tube Q1 are electrically connected, and are used for controlling on-off of the MOS tube Q1.

3. The drive circuit according to claim 1, characterized by The power supply module S2 further comprises a voltage stabilizing diode D2; a positive electrode of the voltage stabilizing diode D2 is electrically connected to a VDD end of the control chip U2 through a capacitor C6, and a negative electrode of the voltage stabilizing diode D2 is electrically connected to the other end of the resistor R15 through a resistor R9.

4. The drive circuit according to claim 1, characterized by The starting unit M3 further comprises a signal output end and an electrolytic capacitor CE2; the signal output end is electrically connected with the lamp load; the signal output end comprises a positive output end D+ and a negative output end D-; the positive output end D+ and the positive electrode of the electrolytic capacitor CE2 are both electrically connected with the output end of the rectifier filter unit M1; the negative output end D- and the negative electrode of the electrolytic capacitor CE2 are both electrically connected with one end of the main winding of the transformer L2.

5. The drive circuit according to any one of claims 1 to 4, characterized in that, The rectifier filter unit M1 comprises a fuse F1, a rectifier bridge B1, an inductor L1, a resistor R1, and electrolytic capacitors CE1 and CE3; a first input end of the rectifier bridge B1 is electrically connected with a neutral line end N, and a second input end of the rectifier bridge B1 is electrically connected with a live line end L through the fuse F1; one end of the inductor L1, one end of the resistor R1, and the positive electrode of the electrolytic capacitor CE1 are all electrically connected with a first output end of the rectifier bridge B1; the other end of the inductor L1 and the other end of the resistor R1 are both electrically connected with the positive electrode of the electrolytic capacitor EC3; the second output end of the rectifier bridge B1, the negative electrode of the electrolytic capacitor CE1, and the negative electrode of the electrolytic capacitor EC3 are all grounded; and the first output end of the rectifier bridge B1 is the output end of the rectifier filter unit M1.

6. The drive circuit according to any one of claims 1 to 4, characterized by The PB2 end of the control chip U2 is electrically connected with the PWM end of the starting chip U1; the control chip U2 transmits the generated PWM signal to the PWM end of the starting chip U1 through the PB2 end, so as to drive the starting chip U1 to control the brightness of the lamp.

7. A driving control method of a touch-adjustable light table lamp, the method is implemented based on the driving circuit of any one of claims 1-6, characterized in that, The method comprises: The mains is converted into direct current by the rectifier filter unit M1 and output to the driving control unit M2 and the starting unit M3; When the working state of the driving circuit is in the standby light-off mode, the MOS tube Q1 in the power supply module S1 is disconnected, and the direct current voltage output by the rectifier filter unit M1 is divided by the resistors R19, R11, R3, R17, R7, and R8 to supply power to the control chip U2; When the control chip U2 receives the touch signal sent by the touch module Touch1, the working state of the driving circuit enters the touch detection mode; the MOS tube Q1 is turned on by the control chip U2, and the direct current voltage output by the rectifier filter unit M1 is divided by the resistors R19, R11, R3, and R17 to supply power to the control chip U2 through the MOS tube Q1; If the touch signal detected by the control chip U2 is an invalid signal, the MOS tube Q1 is turned off by the control chip U2, and the working state of the driving circuit returns to the standby light-off mode; If the touch signal detected by the control chip U2 is a valid signal, the starting chip U1 is driven by the control chip U2, and the MOS tube Q1 is turned off, so that the working state of the driving circuit enters the light-on mode.

8. The drive control method according to claim 7, characterized by, When the working state of the driving circuit is in the light-on mode, the direct current voltage output by the rectifier filter unit M1 is transformed and coupled by the transformer L2, and then supplied to the control chip U2 through the diode D1 and the resistor R15 in the power supply module S2.

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