Power-on time sequence control circuit
By using a single-control-signal power-on timing control circuit, and utilizing level conversion and auxiliary power supply circuits, the high cost and startup sequence issues caused by multiple control signals after LED bipolar drive dimming and shutdown are solved, achieving low-cost circuit stability and efficiency improvement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- GUANGDONG LYFORD TECH CO LTD
- Filing Date
- 2025-04-21
- Publication Date
- 2026-05-01
AI Technical Summary
Existing technologies require multiple control signals and hardware coordination after LED bipolar drive dimming is turned off, resulting in high costs and difficulty in achieving APFC power correction and sequential startup of subsequent circuits, which can easily lead to voltage pull-down and multiple startup problems.
A power-on timing control circuit with a single control signal is used. The dimming signal is converted into a level signal through a level conversion control circuit, which controls the high-precision constant current LED control circuit to perform delay processing. The high-precision constant current LED control circuit is powered by an auxiliary power supply circuit, thus realizing the delay control of two power supplies.
It achieves low-cost single-signal control, ensures the sequential startup of APFC power correction and subsequent circuits, avoids voltage pull-down and multiple startup issues, and improves circuit stability and efficiency.
Smart Images
Figure CN224191838U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of electronic circuit technology, and in particular to a power-on timing control circuit. Background Technology
[0002] After the LED bipolar driver dimming is turned off, it must meet the European ERP standard of ≤0.5W. Usually, the main power supply is cut off. When dimming is turned on from off, it is necessary to ensure that APFC power correction starts first, and then the subsequent circuit starts. If the subsequent stage starts first, it will pull down the voltage of the previous stage, which will lead to multiple starts.
[0003] Traditional methods use microcontroller control, such as Figure 1 As shown, the APFC power correction circuit is started first, and then the subsequent circuit is started after a delay. This requires two control signals. This method involves many components, is costly, and requires the cooperation of software and hardware development.
[0004] Therefore, it is necessary to provide a power-on timing control circuit. Utility Model Content
[0005] This utility model provides a power-on timing control circuit, which provides a single control signal to control two power supplies with a delay between the two power supplies. When dimming changes from off to on, the dimming signal is first converted into a level signal by a level conversion control circuit, so that the high-precision constant current LED control circuit performs delay processing, and the auxiliary power supply circuit is controlled to supply power to the high-precision constant current LED control circuit.
[0006] This utility model provides a power-on timing control circuit, including: a rectifier and filter circuit, a high-precision constant current LED control circuit, an auxiliary power supply circuit, a level conversion control circuit, a power supply circuit, and a physical shutdown and constant current circuit; the rectifier and filter circuit is connected to the high-precision constant current LED control circuit; the high-precision constant current LED control circuit is connected to the physical shutdown and constant current circuit; the power supply circuit is connected to the high-precision constant current LED control circuit; the auxiliary power supply circuit is connected to the high-precision constant current LED control circuit and the level conversion control circuit; the level conversion control circuit is connected to the physical shutdown and constant current circuit.
[0007] Furthermore, the rectifier filter circuit is used to rectify the AC signal input from the power grid into a smooth DC signal based on rectifier bridges BD1 and BD2, while filtering out noise signals in the power grid.
[0008] Furthermore, the high-precision constant current LED control circuit includes a PFC power correction circuit, a BUCK step-down circuit, and a dimming control unit; the PFC power correction circuit is connected to the BUCK step-down circuit; the dimming control unit is connected to the BUCK step-down circuit; the dimming control unit is used to convert the input signal into a PWM signal.
[0009] Furthermore, the auxiliary power supply circuit provides a 12V constant voltage output to ensure the power supply voltage required by the level conversion control circuit and the dimming control unit.
[0010] Furthermore, the power supply circuit includes a BUCK power supply delay start-up circuit and a PFC power supply circuit. The BUCK power supply delay start-up circuit is used to delay the charging time of capacitor C16 through resistor R60. When the voltage reaches the clamping voltage of Zener diode ZD3, transistor Q20 turns on and pulls down the base voltage of transistor Q18. Resistor R4 and Zener diode ZD1 form a basic voltage regulator circuit, and the voltage is stabilized at the Zener value of Zener diode ZD1. Zener diode ZD1 is connected to the base of transistor Q10, and the emitter of transistor Q10 outputs, forming a transistor emitter follower to output a stable voltage VCC2. The PFC power supply circuit outputs a stable voltage VCC1 based on the emitter of transistor Q17.
[0011] Furthermore, the PFC power supply circuit is connected to the PFC power correction circuit; the BUCK power supply delay start circuit is connected to the BUCK step-down circuit; the level conversion control circuit is connected to the PFC power supply circuit, the BUCK power supply delay start circuit, and the physical shutdown and constant current circuit respectively; and the dimming control unit is connected to the level conversion control circuit.
[0012] Furthermore, the stabilizing voltage VCC2 is used to power the control chip U8 in the BUCK step-down circuit; the stabilizing voltage VCC1 is used to power the control chip U1 in the PFC power correction circuit.
[0013] Furthermore, a physical shutdown and constant current circuit is used to output rectified current and to physically shut off the LED light through relay K1, resulting in no afterglow.
[0014] Furthermore, the level conversion control circuit, when the dimming control unit changes from off to on, converts the PWM1 signal input from the dimming control unit into an equivalent DC level signal using a filter component composed of diode D8, resistor R64, resistor R8, and capacitor C8. This equivalent DC level signal is then input to the base of transistor Q3, causing Q3 to conduct. Through the transmission of optocoupler U2, the auxiliary winding power supply VCC / A, via diode D7, generates BVCC to power the BUCK power supply delay start circuit; the auxiliary winding power supply VCC / A, via diode D13, generates PVCC to power the PFC power supply circuit. Resistor R75 provides bias current to transistor Q11, causing Q11 to conduct. A WYH grounding loop is provided, which, combined with VCC / A, enables the physical shutdown and the activation of relay K1 in the constant current circuit.
[0015] Furthermore, when the dimming control unit is turned off, the level conversion control circuit outputs a low level, and the power supply to the control chip U1 in the PFC power correction circuit and the control chip U8 in the BUCK step-down circuit is cut off, stopping their operation. When the dimming control unit goes from dimming off to dimming on, the control chip U3 in the dimming control unit sends a PWM1 signal with an amplitude of 5V. Part of the PWM1 signal is converted into a DC high level by the level conversion control circuit, and the main power supply and relay K1 are powered through the optocoupler. The other part of the PWM1 signal is transmitted to the control chip U8 in the BUCK step-down circuit through the optocoupler as a dimming signal.
[0016] Compared with the prior art, this utility model has the following advantages and beneficial effects: it provides a control method that uses a single control signal to control two power supplies with a delay between the two power supplies; firstly, the dimming signal is converted into a level signal through a level conversion control circuit, so that the high-precision constant current LED control circuit performs delay processing, and controls the auxiliary power supply circuit to supply power to the high-precision constant current LED control circuit.
[0017] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.
[0018] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0019] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:
[0020] Figure 1 A schematic diagram of a traditional microcontroller timing control method;
[0021] Figure 2 This is a schematic diagram of the power-on timing control circuit.
[0022] Figure 3 This is a schematic diagram showing the connection structure of the rectifier filter circuit and the high-precision constant current LED control circuit.
[0023] Figure 4 This is a schematic diagram showing the structure and connection of a high-precision constant current LED control circuit, a level conversion control circuit, a power supply circuit, a physical shutdown circuit, and a constant current circuit.
[0024] Figure 5 This is a schematic diagram of the auxiliary power supply circuit structure. Detailed Implementation
[0025] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.
[0026] This utility model provides a power-on timing control circuit, such as Figure 2 As shown, it includes: a rectifier and filter circuit, a high-precision constant current LED control circuit, an auxiliary power supply circuit, a level conversion control circuit, a power supply circuit, and a physical shutdown and constant current circuit; the rectifier and filter circuit is connected to the high-precision constant current LED control circuit; the high-precision constant current LED control circuit is connected to the physical shutdown and constant current circuit; the power supply circuit is connected to the high-precision constant current LED control circuit; the auxiliary power supply circuit is connected to the high-precision constant current LED control circuit and the level conversion control circuit; the level conversion control circuit is connected to the physical shutdown and constant current circuit.
[0027] The working principle of the above technical solution is as follows: In order to realize the power-on timing control circuit, this utility model proposes a rectifier filter circuit, a high-precision constant current LED control circuit, an auxiliary power supply circuit, a level conversion control circuit, a power supply circuit, a physical shutdown and constant current circuit; the rectifier filter circuit is connected to the high-precision constant current LED control circuit; the high-precision constant current LED control circuit is connected to the physical shutdown and constant current circuit; the power supply circuit is connected to the high-precision constant current LED control circuit; the auxiliary power supply circuit is connected to the high-precision constant current LED control circuit and the level conversion control circuit; the level conversion control circuit is connected to the physical shutdown and constant current circuit.
[0028] The beneficial effects of the above technical solution are as follows: By adopting the solution provided in this embodiment, through the connection structure of the rectifier filter circuit, the high-precision constant current LED control circuit, the auxiliary power supply circuit, the level conversion control circuit, the power supply circuit, the physical shutdown and the constant current circuit, a control method can be provided that controls two power supplies with a single control signal and the two power supplies have a delay; when dimming changes from off to on, the dimming signal is first converted into a level signal through the level conversion control circuit, so that the high-precision constant current LED control circuit performs delay processing, and the auxiliary power supply circuit is controlled to supply power to the high-precision constant current LED control circuit.
[0029] In one embodiment, such as Figure 3 As shown, the rectifier and filter circuit is used to rectify the AC signal input from the power grid into a smooth DC signal based on rectifier bridges BD1 and BD2, while filtering out noise signals in the power grid.
[0030] The working principle of the above technical solution is as follows: The rectifier and filter circuit in this utility model is based on rectifier bridge BD1 and rectifier bridge BD2, which rectifies the AC signal input from the power grid into a smooth DC signal, while filtering out noise signals in the power grid.
[0031] The beneficial effects of the above technical solution are as follows: by adopting the solution provided in this embodiment, a smooth DC signal can be obtained through the setting of the rectifier and filter circuit.
[0032] In one embodiment, such as Figure 3 As shown, the high-precision constant current LED control circuit includes a PFC power correction circuit, a BUCK step-down circuit, and a dimming control unit; the PFC power correction circuit is connected to the BUCK step-down circuit; the dimming control unit is connected to the BUCK step-down circuit; the dimming control unit is used to convert the input signal into a PWM signal.
[0033] The working principle of the above technical solution is as follows: The high-precision constant current LED control circuit in this utility model includes a PFC power correction circuit, a BUCK step-down circuit, and a dimming control unit; the PFC power correction circuit is connected to the BUCK step-down circuit; the dimming control unit is connected to the BUCK step-down circuit; the dimming control unit is used to convert the input signal into a PWM signal.
[0034] The beneficial effects of the above technical solution are as follows: by using the solution provided in this embodiment, the high-precision constant current LED control circuit can be divided into a PFC power correction circuit, a BUCK step-down circuit and a dimming control unit, which can achieve efficient control of the dimming signal.
[0035] In one embodiment, such as Figure 5 As shown, the auxiliary power supply circuit is used to provide a 12V constant voltage output to ensure the power supply voltage required by the level conversion control circuit and the dimming control unit.
[0036] The working principle of the above technical solution is as follows: The auxiliary power supply circuit in this utility model is used to provide a 12V constant voltage output to ensure the power supply voltage required by the level conversion control circuit and the dimming control unit.
[0037] The beneficial effects of the above technical solution are as follows: by adopting the solution provided in this embodiment, the stable operation of the level conversion control circuit and the dimming control unit can be guaranteed through the auxiliary power supply circuit.
[0038] In one embodiment, such as Figure 3 , Figure 4As shown, the power supply circuit includes a BUCK power supply delay start-up circuit and a PFC power supply circuit. The BUCK power supply delay start-up circuit is used to delay the charging time of capacitor C16 through resistor R60. When the voltage reaches the clamping voltage of Zener diode ZD3, transistor Q20 turns on and pulls down the base voltage of transistor Q18. Resistor R4 and Zener diode ZD1 form a basic voltage regulator circuit, and the voltage is stabilized at the Zener value of Zener diode ZD1. Zener diode ZD1 is connected to the base of transistor Q10, and the emitter of transistor Q10 outputs, forming a transistor emitter follower to output a stable voltage VCC2. The PFC power supply circuit outputs a stable voltage VCC1 based on the emitter of transistor Q17.
[0039] The working principle of the above technical solution is as follows: The power supply circuit in this utility model includes a BUCK power supply delay start circuit and a PFC power supply circuit; the BUCK power supply delay start circuit is used to delay the charging time of capacitor C16 through resistor R60. When the voltage reaches the clamping voltage of Zener diode ZD3, transistor Q20 is turned on and pulls down the base voltage of transistor Q18. Resistor R4 and Zener diode ZD1 form a basic voltage regulator circuit, and the voltage is stabilized at the Zener value of Zener diode ZD1. Zener diode ZD1 is connected to the base of transistor Q10, and the emitter of transistor Q10 outputs, forming a transistor emitter follower to output a stable voltage VCC2; the PFC power supply circuit outputs a stable voltage VCC1 based on the emitter of transistor Q17.
[0040] The beneficial effects of the above technical solution are as follows: by using the solution provided in this embodiment, the power supply circuit can be divided into a BUCK power supply delay start circuit and a PFC power supply circuit, which can ensure different power supply operations.
[0041] In one embodiment, such as Figure 4 As shown, the PFC power supply circuit is connected to the PFC power correction circuit; the BUCK power supply delay start circuit is connected to the BUCK step-down circuit; the level conversion control circuit is connected to the PFC power supply circuit, the BUCK power supply delay start circuit, and the physical shutdown and constant current circuit respectively; the dimming control unit is connected to the level conversion control circuit.
[0042] The working principle of the above technical solution is as follows: the PFC power supply circuit in this utility model is connected to the PFC power correction circuit; the BUCK power supply delay start circuit is connected to the BUCK step-down circuit; the level conversion control circuit is connected to the PFC power supply circuit, the BUCK power supply delay start circuit and the physical shutdown and constant current circuit respectively; and the dimming control unit is connected to the level conversion control circuit.
[0043] The beneficial effects of the above technical solution are as follows: By adopting the solution provided in this embodiment, the normal and stable operation of the PFC power correction circuit and the BUCK power supply delay start circuit and the BUCK step-down circuit can be guaranteed through the connection of the PFC power supply circuit and the PFC power correction circuit, as well as the connection of the BUCK power supply delay start circuit and the BUCK step-down circuit.
[0044] In one embodiment, such as Figure 4 As shown, the stabilizing voltage VCC2 is used to power the control chip U8 in the BUCK step-down circuit; the stabilizing voltage VCC1 is used to power the control chip U1 in the PFC power correction circuit.
[0045] The working principle of the above technical solution is as follows: the stable voltage VCC2 in this utility model supplies power to the control chip U8 in the BUCK step-down circuit; the stable voltage VCC1 supplies power to the control chip U1 in the PFC power correction circuit.
[0046] The beneficial effects of the above technical solution are as follows: by adopting the solution provided in this embodiment, the stable operation of the BUCK step-down circuit and the PFC power correction circuit can be guaranteed through two stable voltages.
[0047] In one embodiment, such as Figure 3 As shown, the physical shutdown and constant current circuit is used to output rectified current and to physically shut off the LED light through relay K1, resulting in no afterglow.
[0048] The working principle of the above technical solution is as follows: The physical shutdown and constant current circuit of this utility model is used to output rectified current and to physically shut off the LED lamp through relay K1, so that there is no afterglow.
[0049] The beneficial effects of the above technical solution are as follows: by adopting the solution provided in this embodiment, direct control of LED lights can be achieved through physical shutdown and constant current circuit.
[0050] In one embodiment, the level shifting control circuit, when the dimming control unit changes from off to on, converts the PWM1 signal input from the dimming control unit into an equivalent DC level signal using a filter component composed of diode D8, resistor R64, resistor R8, and capacitor C8. This equivalent DC level signal is then input to the base of transistor Q3, causing Q3 to conduct. Through the transmission of optocoupler U2, the auxiliary winding power supply VCC / A, via diode D7, generates BVCC to power the BUCK power supply delay start circuit; the auxiliary winding power supply VCC / A, via diode D13, generates PVCC to power the PFC power supply circuit; and through resistor R75, it provides bias current to transistor Q11, causing Q11 to conduct. A WYH grounding loop is provided, which, combined with VCC / A, enables the physical shutdown and the relay K1 in the constant current circuit to turn on.
[0051] The working principle of the above technical solution is as follows: The level conversion control circuit, when the dimming control unit changes from off to on, converts the PWM1 signal input from the dimming control unit into an equivalent DC level signal using a filter component composed of diode D8, resistor R64, resistor R8, and capacitor C8. The equivalent DC level signal is then input to the base of transistor Q3, turning on transistor Q3. Through the transmission of optocoupler U2, the auxiliary winding power supply VCC / A, through diode D7, generates BVCC to power the BUCK power supply delay start circuit; the auxiliary winding power supply VCC / A, through diode D13, generates PVCC to power the PFC power supply circuit, and through resistor R75, provides bias current to transistor Q11, turning on transistor Q11; a WYH grounding loop is provided, which, combined with VCC / A, enables the physical shutdown and the relay K1 in the constant current circuit to turn on.
[0052] The beneficial effects of the above technical solution are as follows: By adopting the solution provided in this embodiment, the PWM1 signal input from the dimming control unit can be converted and processed when the dimming control unit is turned off to on, thereby realizing the control of the physical shutdown and the relay K1 in the constant current circuit.
[0053] In one embodiment, when the dimming control unit is turned off, the level conversion control circuit outputs a low level, and the power supply to the control chip U1 in the PFC power correction circuit and the control chip U8 in the BUCK step-down circuit is cut off, stopping their operation. When the dimming control unit goes from dimming off to dimming on, the control chip U3 in the dimming control unit sends a PWM1 signal with an amplitude of 5V. Part of the PWM1 signal is converted into a DC high level by the level conversion control circuit and controlled by the optocoupler to power the main power supply and the relay K1. The other part of the PWM1 signal is transmitted to the control chip U8 in the BUCK step-down circuit as a dimming signal through the optocoupler.
[0054] The working principle of the above technical solution is as follows: When the dimming control unit is turned off, the level conversion control circuit outputs a low level, and the power supply to the control chip U1 in the PFC power correction circuit and the control chip U8 in the BUCK step-down circuit is cut off, and they stop working; when the dimming control unit goes from dimming off to dimming on, the control chip U3 in the dimming control unit sends a PWM1 signal with an amplitude of 5V; part of the PWM1 signal is converted into a DC high level by the level conversion control circuit, and the main power supply and relay K1 are controlled by the optocoupler; the other part of the PWM1 signal is transmitted to the control chip U8 in the BUCK step-down circuit as a dimming signal through the optocoupler.
[0055] The beneficial effects of the above technical solution are as follows: by using the solution provided in this embodiment, the different working modes of the PFC power correction circuit and the BUCK step-down circuit can be realized by turning the dimming control unit off and on, thereby realizing the function of the control circuit.
[0056] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.
Claims
1. A power-on timing control circuit, characterized by comprising: include: Rectifier and filter circuit, high-precision constant current LED control circuit, auxiliary power supply circuit, level conversion control circuit, power supply circuit, physical shutdown and constant current circuit; The rectifier and filter circuit is connected to the high-precision constant current LED control circuit; the high-precision constant current LED control circuit is connected to the physical shutdown and constant current circuit; the power supply circuit is connected to the high-precision constant current LED control circuit; the auxiliary power supply circuit is connected to the high-precision constant current LED control circuit and the level conversion control circuit; the level conversion control circuit is connected to the physical shutdown and constant current circuit.
2. The power-on timing control circuit according to claim 1, characterized in that, The rectifier and filter circuit is used to rectify the AC signal input from the power grid into a smooth DC signal based on rectifier bridges BD1 and BD2, while filtering out noise signals in the power grid.
3. The power-on timing control circuit of claim 1, wherein, The high-precision constant current LED control circuit includes a PFC power correction circuit, a BUCK step-down circuit, and a dimming control unit; the PFC power correction circuit is connected to the BUCK step-down circuit; the dimming control unit is connected to the BUCK step-down circuit; the dimming control unit is used to convert the input signal into a PWM signal.
4. The power-on timing control circuit of claim 3, wherein, The auxiliary power supply circuit provides a 12V constant voltage output to ensure the power supply voltage required by the level conversion control circuit and the dimming control unit.
5. The power-on timing control circuit of claim 3, wherein, The power supply circuit includes a BUCK power supply delay start-up circuit and a PFC power supply circuit. The BUCK power supply delay start-up circuit is used to delay the charging time of capacitor C16 through resistor R60. When the voltage reaches the clamping voltage of Zener diode ZD3, transistor Q20 turns on and pulls down the base voltage of transistor Q18. Resistor R4 and Zener diode ZD1 form a basic voltage regulator circuit, and the voltage is stabilized at the Zener value of Zener diode ZD1. Zener diode ZD1 is connected to the base of transistor Q10, and the emitter of transistor Q10 outputs, forming a transistor emitter follower to output a stable voltage VCC2. The PFC power supply circuit outputs a stable voltage VCC1 based on the emitter of transistor Q17.
6. The power-on timing control circuit according to claim 5, characterized in that, The PFC power supply circuit is connected to the PFC power correction circuit; the BUCK power supply delay start circuit is connected to the BUCK step-down circuit; the level conversion control circuit is connected to the PFC power supply circuit, the BUCK power supply delay start circuit, and the physical shutdown and constant current circuit respectively; the dimming control unit is connected to the level conversion control circuit.
7. The power-on timing control circuit according to claim 5, characterized in that, The stabilizing voltage VCC2 is used to power the control chip U8 in the BUCK step-down circuit; the stabilizing voltage VCC1 is used to power the control chip U1 in the PFC power correction circuit.
8. The power-on timing control circuit of claim 1, wherein, The physical shutdown and constant current circuit is used to output rectified current and to physically shut off the LED light through relay K1, resulting in no afterglow.
9. A power-on timing control circuit according to claim 5, characterized in that, The level conversion control circuit, when the dimming control unit changes from off to on, converts the PWM1 signal input from the dimming control unit into an equivalent DC level signal using a filter component composed of diode D8, resistor R64, resistor R8, and capacitor C8. This equivalent DC level signal is then input to the base of transistor Q3, turning on Q3. Through optocoupler U2, the auxiliary winding power supply VCC / A, via diode D7, generates BVCC to power the BUCK power supply delay start circuit; the auxiliary winding power supply VCC / A, via diode D13, generates PVCC to power the PFC power supply circuit. Resistor R75 provides bias current to transistor Q11, turning it on. A grounding loop (WYH) is provided, which, combined with VCC / A, enables the physical shutdown and the activation of relay K1 in the constant current circuit.
10. A power-on timing control circuit according to claim 9, characterized in that, When the dimming control unit is turned off, the level conversion control circuit outputs a low level, and the power supply to the control chip U1 in the PFC power correction circuit and the control chip U8 in the BUCK step-down circuit is cut off, stopping their operation. When the dimming control unit goes from dimming off to dimming on, the control chip U3 in the dimming control unit sends a PWM1 signal with an amplitude of 5V. Part of the PWM1 signal is converted into a DC high level by the level conversion control circuit, and the main power supply and relay K1 are powered through the optocoupler. The other part of the PWM1 signal is transmitted to the control chip U8 in the BUCK step-down circuit through the optocoupler as a dimming signal.