An indicator light steady state response circuit for a power supply
By designing a steady-state response circuit and utilizing the coordinated operation of optocouplers and field-effect transistors, the problems of traditional indicator light flickering and delayed extinguishing after power failure were solved, achieving instant response and stable power supply for the indicator lights, thus improving user experience and device safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGYIN WONDER ELECTRONIC CO LTD
- Filing Date
- 2025-05-21
- Publication Date
- 2026-06-09
AI Technical Summary
Traditional indicator lights flicker due to their current and voltage pulse characteristics, which can affect eyesight and sleep, generate electromagnetic interference, and cause delayed extinguishing after power failure, leading to misoperation.
A steady-state response circuit was designed, comprising a power detection circuit, a power conversion circuit, a PWM transformer control circuit, and a synchronous rectification circuit. Through the coordinated operation of an optocoupler and a field-effect transistor, the instantaneous response and stable power supply of the indicator light are achieved.
The indicator light flashing has been eliminated, ensuring that it turns off immediately in the event of a power outage, improving the user experience and device safety, and enhancing the stability and reliability of the circuit.
Smart Images
Figure CN224343418U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of steady-state response circuit technology, specifically to a steady-state response circuit for an indicator light in a power supply device. Background Technology
[0002] Traditional power indicator lights are ubiquitous in daily life and work, including in ordinary household appliances, laboratory appliances, fixed sockets, and mobile sockets. Because most of them use conventional half-wave or full-wave AC rectification to drive the lights, the pulse characteristics of the current and voltage cause the indicator lights to flicker for extended periods. This can cause visual interference at night, potentially damaging eyesight and affecting sleep quality. Furthermore, it generates electromagnetic interference, which can be difficult to detect with highly sensitive detection equipment, and also increases the cumulative impact of electromagnetic radiation on the human body. In addition, because these indicator lights typically use high-capacity electrolytic capacitors as filtering components, they do not immediately turn off after power is cut off; some remain lit for more than 10 seconds, leading to inaccurate judgment of the switch status and resulting in misoperation or repeated operation. Flicker-free indicator light design is also a crucial aspect for high-quality, high-performance electrical products. Summary of the Invention
[0003] The core objective of this invention is to provide an innovative charging power indicator circuit structure and a device equipped with the circuit, aiming to solve the problems of flashing AC power indicator lights and delayed extinguishing of DC power indicator lights when power is cut off in the prior art, so as to achieve synchronous and real-time response of indicator lights and AC power supply, significantly improve the user experience, enhance the safety and reliability of the product, and meet the market demand for high-quality charging power supplies.
[0004] To achieve the above objectives, this utility model designs a steady-state response circuit for an indicator light in a power supply device. The steady-state response circuit includes a power detection circuit, a power conversion circuit, a PWM transformer control circuit, and a synchronous rectification circuit connected in sequence. The output terminal of the synchronous rectification circuit is simultaneously connected to an indicator light circuit and a feedback circuit.
[0005] The power detection circuit consists of a 5th diode, a 29th resistor, a 6th optocoupler LED, and a 30th resistor connected in series in sequence, and this series branch is connected in parallel between the two input terminals of the AC power supply.
[0006] The power detection circuit is used to detect the input status of AC power in real time. When there is AC power input, the 29th resistor and the 30th resistor are used to limit the current and divide the voltage of the electrical signal to ensure that the electrical signal input to the light-emitting diode of the 6th optocoupler is within a suitable range, so that the light-emitting diode of the 6th optocoupler can emit a light signal of corresponding intensity according to the state of AC power, thereby realizing effective detection of AC power.
[0007] The power conversion circuit includes a bridge rectifier, the output of which is connected to the PWM transformer control circuit via a third inductor.
[0008] When an AC signal enters the circuit, the bridge rectifier rectifies the input AC power and converts it into DC power; the third inductor is used to suppress sudden changes in current and smooth the current waveform, while working in conjunction with the subsequent PWM transformer control circuit to further adjust and convert the voltage.
[0009] The PWM transformer control circuit includes a PWM control circuit and a transformer circuit. The PWM control circuit is mainly composed of a power management chip, whose feedback pin is connected to the photosensitive element of the first optocoupler. The signal source of the photosensitive element is the light-emitting diode of the first optocoupler in the feedback circuit. The output signal of the power management chip is connected to one end of the primary winding of the transformer circuit through the drain pin.
[0010] The photosensitive element of the first optocoupler is used to receive the light emitted by the light-emitting diode of the first optocoupler in the feedback circuit, and convert the intensity of the emitted light into an electrical signal and transmit it to the power management chip. The power management chip analyzes the feedback signal in real time, adjusts the duty cycle of its switching pin, and then controls the energy transmission of the primary winding of the transformer.
[0011] The synchronous rectification circuit is based on a synchronous rectification controller. Its power input pin is electrically connected to the output of the PWM transformer control circuit via a capacitor. The output signal of its drain pin is filtered by a capacitor and then transmitted to the feedback circuit and the indicator circuit respectively. The feedback circuit is composed of a resistor and an optocoupler light-emitting diode.
[0012] The synchronous rectifier circuit is used to rectify and regulate the input signal. Through its internal control circuit, it adjusts its operating state in real time according to changes in the input signal, improving rectification efficiency and reducing energy loss. The output signal of the synchronous rectifier controller is filtered by a capacitor and then transmitted to the indicator light circuit and feedback circuit. The filtered DC power provides a stable operating power supply for the indicator light circuit, ensuring stable operation of the indicator light.
[0013] The feedback circuit is used to transmit the received rectified electrical signal to the light-emitting diode of the first optocoupler. The light-emitting diode of the first optocoupler works in conjunction with the photosensitive element of the first optocoupler in the PWM control circuit to provide real-time feedback on the fluctuation of the output power to the power management chip. The power management chip adjusts the duty cycle of its switching pin accordingly, thereby controlling the energy transmission of the primary winding of the transformer and maintaining the stability of the output power.
[0014] The indicator light circuit block includes a photosensitive element of the 6th optocoupler, a resistor, a capacitor, a field-effect transistor, and an LED indicator light. The input signal is transmitted to the gate of the field-effect transistor after passing through the photosensitive element of the 6th optocoupler and then through an RC filter circuit. The source of the field-effect transistor is grounded, and the drain is connected to the cathode of the LED indicator light through the 28th resistor. The anode of the LED indicator light is connected to the 4th pin of the 6th optocoupler, and the signal is connected to the indicator light circuit through the 4th pin of the photosensitive element of the 6th optocoupler.
[0015] The photosensitive element of the sixth optocoupler cooperates with the light-emitting diode of the sixth optocoupler in the power detection circuit. In the power detection circuit, when the light-emitting diode of the sixth optocoupler senses the AC power supply, it will emit light of corresponding intensity according to the characteristics of the AC power supply. The photosensitive element of the sixth optocoupler in the indicator light circuit can keenly sense the light and accurately convert the received light signal into an electrical signal through the internal photoelectric conversion mechanism. The electrical signal is then transmitted to the gate of the field-effect transistor.
[0016] As a key controllable switching element in the indicator light circuit, the field-effect transistor (FET) conducts upon receiving an electrical signal from the photosensitive element of the sixth optocoupler if the signal meets its conduction condition. Once the FET is on, the indicator light circuit forms a closed loop, allowing current to flow smoothly and illuminating the LED indicator, clearly and intuitively showing the user that the track socket is in operation. Conversely, when the LED of the sixth optocoupler does not detect AC power input, it will not emit light. In this case, the photosensitive element of the sixth optocoupler cannot receive light and therefore cannot generate the electrical signal to turn on the FET, preventing the indicator light circuit from forming a closed loop. Simultaneously, because the circuit cannot form a closed loop, the stored charge in the capacitor cannot maintain the LED indicator's illumination, effectively preventing the LED indicator from delaying its extinguishing, thus intuitively demonstrating the operating status of the power supply equipment to the user.
[0017] Furthermore, the negative output terminal of the power conversion circuit is connected to the negative terminal of the first electrolytic capacitor and grounded through the second fuse; the positive terminal of the first electrolytic capacitor is interconnected with the positive output terminal of the bridge rectifier and the third inductor, and the third inductor is grounded through the second electrolytic capacitor.
[0018] The second electrolytic capacitor works in conjunction with the first electrolytic capacitor to enhance the filtering effect of the power conversion circuit, ensuring a stable and reliable power signal input to the PWM transformer control circuit. The electrolytic capacitor has a large capacitance value, capable of storing a certain amount of charge, and acts as a buffer when the power supply voltage fluctuates. To ensure circuit safety, the negative output terminal of the bridge rectifier is grounded through a fuse. When an abnormally large current occurs in the circuit, the fuse will blow, thereby cutting off the circuit and preventing excessive current from damaging other components, thus protecting the safe operation of the entire circuit.
[0019] Furthermore, in the transformer circuit, one end of the primary winding of the transformer is electrically connected to the drain pin of the power management chip in the PWM control circuit, and one end of the auxiliary winding of the transformer is electrically connected to the switch pin of the power management chip. An RCD clamping circuit consisting of a second diode, a ninth resistor, a fourth resistor, and a fifth capacitor is connected in parallel across the two ends of the primary winding of the transformer. The output signal of the PWM transformer control circuit is transmitted to the synchronous rectification circuit through the secondary winding of the transformer.
[0020] It should be noted that the transformer auxiliary winding generates a stable voltage after being filtered by a capacitor. This voltage provides the operating power to the power management chip through the drain pin. The drain pin also works in conjunction with the switching pin to compensate for voltage fluctuations by adjusting the conduction timing of the field-effect transistors inside the power management chip, thereby further regulating the energy transfer of the transformer primary winding.
[0021] In the PWM control circuit, when the MOSFET inside the power management chip is turned off, the reverse spike voltage generated by the transformer leakage inductance will form a conduction path through D2. At this time, D2 acts as a clamping diode to guide the spike energy to the RC absorption network, thereby limiting the drain voltage amplitude and protecting the MOSFET inside the power management chip from being broken down.
[0022] Furthermore, in the PWM control circuit, the feedback pin of the power management chip is also connected to a second capacitor, the other end of which is grounded, and a sixth transient diode is connected in parallel across the second capacitor.
[0023] Furthermore, the PWM control circuit also includes a third resistor, a first diode, and a first fuse connected in series between the power management chip's switch pin and the transformer's auxiliary winding; the first diode is grounded through a parallel-connected 19th capacitor and a 20th capacitor.
[0024] Furthermore, the synchronous rectification circuit also includes a fourth electrolytic capacitor, a fifth electrolytic capacitor, and a ninth capacitor connected in parallel between a drain pin of the synchronous rectification controller and ground.
[0025] Furthermore, in the indicator light circuit, the photosensitive element of the sixth optocoupler is grounded through a low-pass filter circuit composed of the third resistor and the second capacitor connected in parallel.
[0026] The steady-state response circuit also includes a USB control output module, which mainly consists of a Type-C connector and a USB-A interface element connected to the USB port controller. The input terminal of the USB control output module is connected to the output terminal of the synchronous rectification circuit, and the output terminal of the USB control output module is connected to the power-consuming device.
[0027] The advantages and beneficial effects of this utility model are as follows:
[0028] 1. Solve the problem of indicator light flickering: The power conversion circuit converts AC power to DC power, and the feedback mechanism of the PWM transformer control circuit and the synchronous rectification circuit further stabilize the power supply of the input indicator light circuit without fluctuations, eliminating flickering when drawing AC power and improving the nighttime user experience.
[0029] 2. Eliminating delayed power-off extinguishing: This invention utilizes the coordinated operation of the LED of the sixth optocoupler in the power detection circuit and the photosensitive element of the sixth optocoupler in the indicator light circuit. When the AC power is disconnected, the LED of the sixth optocoupler immediately stops working, synchronously triggering the photosensitive element of the sixth optocoupler to cut off the drive signal of the field-effect transistor, causing the LED indicator to quickly extinguish. This allows users to accurately determine whether the socket is powered off, avoiding misunderstandings caused by delayed extinguishing of the indicator light, and significantly improving the safety and convenience of using the track socket.
[0030] 3. Improved circuit stability and reliability: The circuit is equipped with multiple protective components, including fuses, transient diodes, and filter circuits composed of various capacitors and resistors. The fuses promptly disconnect the circuit during overcurrent to protect other components; the transient diodes quickly clamp the voltage during momentary overvoltage to protect chips and devices; the capacitor and resistor filter circuit effectively filters out noise interference, improving the overall stability and reliability of the circuit and extending the service life of the power supply equipment. Attached Figure Description
[0031] Figure 1 This is a circuit block diagram of this utility model;
[0032] Figure 2 This is the schematic diagram of the power detection circuit of this utility model.
[0033] Figure 3 This is a schematic diagram of the power conversion circuit of this utility model;
[0034] Figure 4 This is a schematic diagram of the PWM transformer control circuit of this utility model;
[0035] Figure 5 This is a schematic diagram of the synchronous rectifier circuit of this utility model;
[0036] Figure 6 This is the circuit diagram of the indicator light of this utility model;
[0037] Figure 7 This is the schematic diagram of the feedback circuit of this utility model;
[0038] Figure 8 This is a circuit schematic diagram of the USB control output module of this utility model;
[0039] Figure 9 This is a system schematic diagram of this utility model. Detailed Implementation
[0040] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solution of this utility model and should not be construed as limiting the scope of protection of this utility model.
[0041] Example 1:
[0042] This embodiment details the circuit connection and operation of the power detection circuit and indicator light circuit.
[0043] like Figure 2 As shown, the power detection circuit consists of the 5th diode D5, the 29th resistor R29, the 6th optocoupler LED U6A, and the 30th resistor R30 connected in series in sequence, and this series branch is connected in parallel between the two input terminals of the AC power supply.
[0044] The power detection circuit is used to detect the input status of AC power in real time. When there is AC power input, resistors R29 (29th) and R30 (30th) are used to limit the current and divide the voltage of the electrical signal to ensure that the electrical signal input to the LED U6A of the 6th optocoupler is within a suitable range. This enables the LED U6A of the 6th optocoupler to emit a light signal of corresponding intensity according to the state of the AC power, thereby achieving effective detection of the AC power.
[0045] like Figure 6As shown, the indicator circuit includes a photosensitive element U6B of the sixth optocoupler, a resistor, a capacitor, a field-effect transistor Q1, and an LED indicator LED1. The input signal is transmitted to the gate of the field-effect transistor Q1 through the photosensitive element U6B of the sixth optocoupler via an RC filter circuit. The source of the field-effect transistor Q1 is grounded, and the drain is connected to the cathode of the LED indicator LED1 via the 28th resistor R28. The anode of the LED indicator LED1 is connected to the 4th pin of the photosensitive element U6B of the sixth optocoupler. The signal is input to the indicator circuit through the 4th pin of the photosensitive element U6B of the sixth optocoupler, and the photosensitive element U6B of the sixth optocoupler is grounded through a low-pass filter circuit composed of the 32nd resistor R32 and the 22nd capacitor C22 connected in parallel.
[0046] As a key controllable switching element in the indicator light circuit, the field-effect transistor Q1 conducts when it receives an electrical signal from the photosensitive element U6B of the sixth optocoupler if the signal meets its conduction condition. In this embodiment, when the AC power is on, the primary side of the photosensitive element of the sixth optocoupler conducts, and the secondary side outputs a high level to the gate of the field-effect transistor Q1, causing Q1 to conduct and the LED indicator LED1 to light up. When the AC power is off, the primary current of the photosensitive element of the sixth optocoupler is interrupted, the secondary side immediately cuts off, the gate voltage of Q1 drops sharply to 0V, Q1 quickly cuts off, and the LED indicator LED1 turns off instantly due to the lack of current flow (response time < 50μs). In this way, the on / off state of the LED indicator LED1 is precisely controlled according to the input signal, avoiding the problem of delayed indicator light extinguishing, thus intuitively showing the user the working status of the track socket.
[0047] Example 2:
[0048] This embodiment describes in detail the circuit connection and operation of the power conversion circuit.
[0049] like Figure 3 As shown, the power conversion circuit includes a bridge rectifier BD1, and the output terminal of the bridge rectifier BD1 is connected to the PWM transformer control circuit via the third inductor L3.
[0050] In this embodiment, the negative output terminal of the power conversion circuit is connected to the negative terminal of the first electrolytic capacitor and grounded through the second fuse; the positive terminal of the first electrolytic capacitor is interconnected with the positive output terminal of the bridge rectifier and the third inductor, and the third inductor is grounded through the second electrolytic capacitor.
[0051] The second electrolytic capacitor EC2 works in conjunction with the first electrolytic capacitor EC1 to enhance the filtering effect of the power conversion circuit, ensuring a stable and reliable power signal input to the PWM transformer control circuit. Electrolytic capacitors have a large capacitance value, capable of storing a certain amount of charge, which acts as a buffer when the power supply voltage fluctuates. To ensure circuit safety, the negative output terminal of the bridge rectifier is grounded through the second fuse L2. When an abnormally large current occurs in the circuit, the second fuse L2 will melt, thereby cutting off the circuit and preventing excessive current from damaging other components, thus protecting the safe operation of the entire circuit.
[0052] When an AC signal enters the circuit, the bridge rectifier BD1 rectifies the input AC power and converts it into DC power. The third inductor L3 is used to suppress sudden changes in current and smooth the current waveform. At the same time, it works in conjunction with the subsequent PWM transformer control circuit to further adjust and convert the voltage. The signal output from the power conversion circuit through the third inductor L3 is first filtered by the second electrolytic capacitor EC2 to further remove high-frequency noise and interference from the signal before being transmitted to the PWM transformer control circuit.
[0053] In this embodiment, an ABS210 bridge rectifier BD1 is used. Based on the unidirectional conductivity of diodes, the ABS210 bridge rectifier BD1 achieves efficient rectification through the bridge connection of four rectifier silicon chips. The ABS210 bridge rectifier BD1 has a high reverse withstand voltage of 1000V, can adapt to voltage fluctuations, and has strong impact resistance, capable of withstanding transient large currents. These advantages enable it to stably rectify AC power into pulsating DC power in the circuit, providing a stable DC foundation for subsequent circuits, improving circuit reliability, reducing the occurrence of faults, and ensuring stable circuit operation.
[0054] The AC power is rectified into pulsating DC by the ABS210 bridge rectifier BD1. After being filtered by the third inductor L3, the first electrolytic capacitor EC1, and the second electrolytic capacitor EC2, a stable DC voltage is output to power the PWM transformer control circuit to drive the transformer T1, thus realizing the primary and secondary energy conversion.
[0055] Example 3:
[0056] like Figure 4 and Figure 7 As shown, this embodiment specifically illustrates the circuit connection and operation details of the PWM transformer control circuit and the feedback circuit.
[0057] The PWM transformer control circuit includes a PWM control circuit and a transformer circuit. The PWM control circuit is mainly based on the power management chip U2, whose feedback pin FB is connected to the photosensitive element U1B of the first optocoupler. The signal source of the photosensitive element is the light-emitting diode U1A of the first optocoupler in the feedback circuit. The output signal of the power management chip is connected to one end of the primary winding of the transformer circuit through the drain pin Drain.
[0058] The photosensitive element U1B of the first optocoupler is used to receive the light emitted by the light-emitting diode U1A of the first optocoupler in the feedback circuit, and convert the intensity of the emitted light into an electrical signal and transmit it to the power management chip U2. The power management chip U2 analyzes the feedback signal in real time and adjusts the duty cycle of its switching pin SW, thereby controlling the energy transmission of the primary winding of the transformer T1.
[0059] Furthermore, in the transformer circuit, one end of the primary winding of the transformer T1 is electrically connected to the drain pin (Drain) of the power management chip U2 in the PWM control circuit, and one end of the auxiliary winding of the transformer T1 is electrically connected to the switch pin (SW) of the power management chip U2. An RCD clamping circuit consisting of a second diode (D2), a ninth resistor (R9), a fourth resistor (R4), and a fifth capacitor (C5) is connected in parallel across the primary winding of the transformer T1. The output signal of the PWM transformer control circuit is transmitted to the synchronous rectification circuit via the secondary winding of the transformer T1.
[0060] It should be noted that the auxiliary winding of transformer T1 generates a stable voltage after being filtered by a capacitor. This voltage provides the operating power to the power management chip through the drain pin Drain. The drain pin Drain also works in conjunction with the switch pin SW to compensate for voltage fluctuations by adjusting the conduction timing of the field-effect transistor inside the power management chip U2, thereby further regulating the energy transfer of the primary winding of transformer T1.
[0061] In the PWM control circuit, when the MOSFET inside the power management chip U2 is turned off, the reverse spike voltage generated by the leakage inductance of the transformer T1 will form a conduction path through the second diode D2. At this time, the second diode D2 acts as a clamping diode to guide the spike energy to the RC absorption network, thereby limiting the drain voltage amplitude and protecting the MOSFET inside the power management chip U2 from being broken down.
[0062] Furthermore, in the PWM control circuit, the feedback pin FB of the power management chip U2 is also connected to a second capacitor C2, the other end of the second capacitor C2 is grounded, and a sixth transient diode D6 is connected in parallel across the two ends of the second capacitor C2.
[0063] The second capacitor C2 is used to smooth voltage fluctuations and filter high-frequency noise, providing a stable DC voltage for the circuit; the sixth transient diode D6, through rectification and protection, prevents reverse current flow and limits the voltage fluctuation range; the second capacitor C2 and the sixth transient diode D6 work together to ensure the stability and reliability of the circuit.
[0064] Furthermore, the PWM control circuit also includes a third resistor R3, a first diode D1, and a first fuse LB1 connected in series between the power management chip U2 switch pin SW and the transformer T1 auxiliary winding; the first diode D1 is grounded through the parallel-connected 19 capacitor C19 and 20 capacitor C20.
[0065] The third resistor, R3, is a current-limiting resistor used to limit the current and protect the switching pin SW of the power management chip U2. The first diode, D1, has the advantages of low forward voltage drop and fast switching speed, acting as a unidirectional conductor to prevent reverse current flow. The first fuse, LB1, also provides overcurrent protection, promptly cutting off the circuit in case of abnormally high current, protecting the entire PWM control circuit. The first diode, D1, is grounded through the parallel capacitors C19 (19) and C20 (20). The filter circuit formed by these two capacitors further filters out noise across the first diode, D1, improving circuit stability.
[0066] In this embodiment, the KP22080WGA power management chip U2 is used. This chip utilizes an integrated enhanced gallium nitride (GaN) switch for high-frequency switching, employing quasi-resonant operation technology to precisely control energy conversion and transmission. During operation, a feedback loop monitors output voltage, current, and other parameters in real time, dynamically adjusting the on and off times of the switch to ensure the output voltage remains stable within the set range. In this embodiment, when the output voltage deviates from the set value, the feedback signal prompts the chip to adjust the switching frequency or duty cycle, thereby maintaining voltage stability. Simultaneously, multiple built-in protection functions continuously monitor the circuit status. Upon detecting abnormalities such as overvoltage or overcurrent, corresponding measures are immediately taken, such as shutting down the switch or adjusting the output, achieving precise control and protection of the circuit and ensuring the efficient, stable, and safe operation of the entire power system.
[0067] Example 4:
[0068] like Figure 5 As shown, this embodiment specifically illustrates the circuit connection and operating details of the synchronous rectification circuit.
[0069] The synchronous rectification circuit is based on a synchronous rectification controller. Its power input pin is electrically connected to the output terminal of the PWM transformer control circuit via a capacitor. The output signal of its drain pin is filtered by a capacitor and then transmitted to the feedback circuit and the indicator circuit respectively. The feedback circuit is composed of a resistor and the light-emitting diode U1A of the first optocoupler.
[0070] The synchronous rectifier circuit is used to rectify and regulate the input signal. Through its internal control circuit, it adjusts its operating state in real time according to changes in the input signal, improving rectification efficiency and reducing energy loss. The output signal of the synchronous rectifier controller is filtered by a capacitor and then transmitted to the indicator light circuit and feedback circuit. The filtered DC power provides a stable operating power supply for the indicator light circuit, ensuring stable operation of the indicator light.
[0071] The feedback circuit is used to transmit the received rectified electrical signal to the light-emitting diode U1A of the first optocoupler. The light-emitting diode U1A of the first optocoupler works in conjunction with the photosensitive element U1B of the first optocoupler in the PWM control circuit to provide real-time feedback on the fluctuation of the output power to the power management chip U2. The power management chip U2 adjusts the duty cycle of its switching pin SW accordingly, thereby controlling the energy transmission of the primary winding of the transformer T1 and maintaining the stability of the output power.
[0072] Furthermore, the synchronous rectification circuit also includes a fourth electrolytic capacitor EC4, a fifth electrolytic capacitor EC5, and a ninth capacitor C9 connected in parallel between a drain pin of the synchronous rectification controller and ground.
[0073] In this embodiment, a KP40661BSGA synchronous rectifier controller U3 is used. This controller manages the input power through its internal circuitry. First, it monitors the input voltage and current. Based on the set output target, such as a stable Vout, it adjusts energy transfer using the high-frequency switching of internal transistors. In this embodiment, when the input voltage changes, the chip obtains the output voltage information in real time through a feedback loop and dynamically adjusts the duty cycle of the switching transistors to ensure the output voltage remains stable at the set value. Simultaneously, the built-in protection module continuously monitors circuit parameters. If overvoltage, overcurrent, or overheating is detected, corresponding measures are immediately taken, such as shutting down the output or adjusting the power, to protect the circuit safety. This achieves precise conversion, distribution, and protection of electrical energy, ensuring that subsequent circuits stably obtain the required power.
[0074] The steady-state response circuit also includes a USB control output module, which mainly consists of a Type-C connector USB1 and a USB-A interface element USB2 connected to the USB port controller U5. The input terminal of the USB control output module is connected to the output terminal of the synchronous rectification circuit, and the output terminal of the USB control output module is connected to the power supply device.
[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.
Claims
1. A steady-state response circuit for an indicator light in a power supply device, characterized in that, The steady-state response circuit includes a power detection circuit, a power conversion circuit, a PWM transformer control circuit, and a synchronous rectification circuit connected in sequence; the output terminal of the synchronous rectification circuit is simultaneously connected to an indicator light circuit and a feedback circuit. The power detection circuit consists of a 5th diode (D5), a 29th resistor (R29), a 6th optocoupler LED (U6A), and a 30th resistor (R30) connected in series in sequence, and this series branch is connected in parallel between the two input terminals of the AC power supply. The power conversion circuit includes a bridge rectifier (BD1), the output of which is connected to the PWM transformer control circuit via a third inductor (L3). The PWM transformer control circuit includes a PWM control circuit and a transformer circuit. The PWM control circuit is mainly composed of a power management chip (U2), whose feedback pin (FB) is connected to the photosensitive element (U1B) of the first optocoupler. The signal source of the photosensitive element is the light-emitting diode (U1A) of the first optocoupler in the feedback circuit. The output signal of the power management chip is connected to one end of the primary winding of the transformer circuit through the drain pin. The synchronous rectification circuit is based on the synchronous rectification controller (U3). Its power input pin (VDD) is electrically connected to the output terminal of the PWM transformer control circuit via a capacitor. Its drain pin (Drain) is connected to the feedback circuit and indicator circuit via a capacitor. The feedback circuit consists of a resistor and the light-emitting diode (U1A) of the first optocoupler. The indicator circuit includes a photosensitive element (U6B) of the sixth optocoupler, a resistor, a capacitor, a field-effect transistor (Q1), and an LED indicator (LED1). The input signal is transmitted to the gate of the field-effect transistor (Q1) after passing through the photosensitive element (U6B) of the sixth optocoupler and then through an RC filter circuit. The source of the field-effect transistor (Q1) is grounded, and the drain is connected to the cathode of the LED indicator (LED1) through the 28th resistor (R28). The anode of the LED indicator (LED1) is connected to the 4th pin of the photosensitive element (U6B) of the sixth optocoupler. The signal is input to the indicator circuit through the 4th pin of the photosensitive element (U6B) of the sixth optocoupler.
2. The steady-state response circuit for an indicator light in a power supply device according to claim 1, characterized in that, The negative output terminal of the power conversion circuit is connected to the negative terminal of the first electrolytic capacitor (EC1) and grounded through the second fuse (L2); the positive terminal of the first electrolytic capacitor (EC1) is interconnected with the positive output terminal of the bridge rectifier (BD1) and the third inductor (L3), and the third inductor is grounded through the second electrolytic capacitor (EC2).
3. The steady-state response circuit for an indicator light in a power supply device according to claim 1, characterized in that, In the transformer circuit, one end of the primary winding of the transformer (T1) is electrically connected to the drain pin of the power management chip (U2) in the PWM control circuit, and one end of the auxiliary winding of the transformer (T1) is electrically connected to the switch pin (SW) of the power management chip (U2). An RCD clamping circuit consisting of a second diode (D2), a ninth resistor (R9), a fourth resistor (R4), and a fifth capacitor (C5) is connected in parallel across the primary winding of the transformer (T1). The output signal of the PWM transformer control circuit is transmitted to the synchronous rectification circuit through the secondary winding of the transformer (T1).
4. The steady-state response circuit for an indicator light in a power supply device according to claim 1, characterized in that, In the PWM control circuit, the feedback pin (FB) of the power management chip (U2) is also connected to a second capacitor (C2), the other end of the second capacitor (C2) is grounded, and a sixth transient diode (D6) is connected in parallel across the two ends of the second capacitor (C2).
5. A steady-state response circuit for an indicator light in a power supply device according to claim 1, characterized in that, The PWM control circuit also includes a third resistor (R3), a first diode (D1), and a first fuse (LB1) connected in series between the power management chip (U2) switch pin (SW) and the transformer (T1) auxiliary winding; the first diode (D1) is grounded through the parallel-connected 19th capacitor (C19) and 20th capacitor (C20).
6. The steady-state response circuit for an indicator light in a power supply device according to claim 1, characterized in that, The synchronous rectification circuit also includes a fourth electrolytic capacitor (EC4), a fifth electrolytic capacitor (EC5), and a ninth capacitor (C9) connected in parallel between a drain pin of the synchronous rectification controller (U3) and ground.
7. A steady-state response circuit for an indicator light in a power supply device according to claim 1, characterized in that, In the indicator light circuit, the photosensitive element (U6B) of the sixth optocoupler is grounded through a low-pass filter circuit consisting of the third resistor (R32) and the second capacitor (C22) connected in parallel.
8. A steady-state response circuit for an indicator light in a power supply device according to claim 1, characterized in that, The steady-state response circuit also includes a USB control output module, which mainly consists of a Type-C connector (USB1) and a USB-A interface element (USB2) connected to the USB port controller (U5). The input terminal of the USB control output module is connected to the output terminal of the synchronous rectification circuit, and the output terminal of the USB control output module is connected to the power-consuming device.