Power supply control circuit

Abstract

The utility model relates to a power supply control circuit which comprises an input filter circuit, a transformer circuit, an output filter circuit, a PWM control circuit, a photoelectric isolation feedback circuit, a power supply circuit, a thermistor circuit and a detection circuit. The detection circuit is used for performing overcurrent compensation on the input high / low voltage; the input filter circuit is connected with a power input end and is sequentially connected with the transformer circuit, the output filter circuit and a power output end; the PWM control circuit comprises a power supply management chip U1; a first control port of the power management chip U1 is connected with the thermistor circuit; a second control port of the power management chip U1 is connected with the detection circuit and a first end of the optoelectronic isolation feedback circuit; a fifth control port of the power management chip U1 is connected with the transformer circuit; the power supply circuit is connected with a sixth control port of the power management chip U1; the second end of the optoelectronic isolation feedback circuit is connected with the output filter circuit. And the low standby power consumption power supply requirement with high and low over-current compensation is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of signal processing, in particular to a power supply control circuit. Background Art

[0002] The power control circuits of some electrical devices typically include a main power circuit and a standby power circuit. In standby mode, the standby power circuit provides auxiliary power to maintain the device's state. To power the device, an external controller outputs a control signal to the main power output control circuit to turn the main power on and off. For example, this control circuit can be used to control electrical devices such as height-adjustable desks and electric fans. However, this power control approach requires a separate auxiliary standby power circuit, as well as an external controller and main power output control circuit, resulting in a complex circuit structure and high cost.

[0003] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the Invention

[0004] The utility model provides a power supply control circuit, which can reduce circuit complexity and production costs, and effectively overcome the defects in the prior art.

[0005] Other features and advantages of the present invention will become apparent from the following detailed description, or may be learned in part by the practice of the present disclosure.

[0006] According to the first aspect of the present invention, a power supply control circuit is provided, comprising: an input filter circuit, a transformer circuit, an output filter circuit, a PWM control circuit, an optoelectronic isolation feedback circuit, a power supply circuit, a thermistor, and a detection circuit; wherein the detection circuit is used to perform overcurrent compensation for the input high / low voltage

[0007] The input filter circuit is connected to the power input terminal, and is sequentially connected to the transformer circuit, the output filter circuit, and the power output terminal;

[0008] The PWM control circuit includes: a power management chip U1; a first control port of the power management chip U1 is connected to the thermistor circuit; a second control port of the power management chip U1 is connected to the detection circuit and the first end of the photoelectric isolation feedback circuit; a fifth control port of the power management chip U1 is connected to the transformer circuit; the power supply circuit is connected to the sixth control port of the power management chip U1; and the second end of the photoelectric isolation feedback circuit is connected to the output filter circuit.

[0009] In some exemplary embodiments, the detection circuit includes: a resistor R71, a resistor R72, a resistor R74, a resistor R75, a filter electrolytic capacitor C33, and a transistor Q10;

[0010] The second control port of the power management chip U1 is connected to the first end of the resistor R71, the second end of the resistor R71 is connected to the first end of the resistor R72, the first end of the filter electrolytic capacitor C33, and the base of the transistor Q10; the second end of the resistor R72 and the second end of the filter electrolytic capacitor C33 are connected to the ground end; the emitter of the transistor Q10 is connected to the third control port of the power management chip U1; the collector of the transistor Q10 is connected to the first end of the resistor R75, the second end of the resistor R75 is connected to the first end of the resistor R74, and the second end of the transistor R74 is connected to the input filter circuit.

[0011] In some exemplary embodiments, the input filter circuit includes an EMC filter circuit and a rectifier filter circuit connected in sequence; wherein the EMC filter circuit is connected to the power input terminal; and the rectifier filter circuit is connected to the input terminal of the transformer circuit.

[0012] In some exemplary embodiments, the eighth control port of the power management chip U1 is connected to the EMC filter circuit and the rectifier filter circuit.

[0013] In some exemplary embodiments, the transformer circuit is connected to the power supply circuit.

[0014] In some exemplary embodiments, the transformer circuit includes a power switch tube and a high-frequency isolation transformer circuit.

[0015] The power control circuit provided in an embodiment of the present invention utilizes a power management chip and connects the second control port of the power management chip to a detection circuit and the first end of an optoelectronic isolation feedback circuit. This ensures that when the main power supply is unloaded and the voltage at pin 2, COMP, of the power management chip U1 is less than 1.8V, the compensation circuit is open, resulting in no power loss. When the output load increases to >3A and the voltage at pin 2, COMP, of the power management chip U1 is greater than 2.5V, the compensation circuit is turned on, and the high- and low-voltage compensation circuits operate. This ensures consistency between the high- and low-voltage input overcurrent protection points. By controlling the difference between the unloaded and loaded COMP output voltages of the power management chip, the high- and low-voltage input overcurrent compensation circuits are turned on and off. When the output is unloaded, the high- and low-voltage compensation circuits are turned off, and when the output current is greater than a set value, the high- and low-voltage compensation circuits are turned on, achieving a low standby power supply with high and low overcurrent compensation. This eliminates the need for additional standby power supply circuits and control circuits, reducing circuit complexity and saving costs.

[0016] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0018] Figure 1 A schematic diagram schematically illustrates the module composition of a power control circuit in an exemplary embodiment of the present utility model;

[0019] Figure 2 Schematically shows a detection circuit diagram of a power control circuit in an exemplary embodiment of the present utility model;

[0020] Figure 3 The figure schematically shows a power control circuit according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0021] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be embodied in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0022] In addition, the accompanying drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings represent the same or similar parts, and thus their repeated description will be omitted.

[0023] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be understood that in the disclosure of the present invention, the orientation or positional relationship indicated by the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore the above terms cannot be understood as limitations on the present invention. Unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," "coupled," and the like should be interpreted broadly. For example, they may refer to fixed or detachable connections, or integration; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components, unless otherwise expressly limited. A person of ordinary skill in the art should be able to understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0024] In view of the shortcomings and deficiencies of the prior art, this exemplary embodiment provides a power supply control circuit that can be used to achieve high and low voltage overcurrent compensation. Figure 1 As shown, the power supply control circuit may include: an input terminal 11, an input filter circuit 12, a transformer circuit 13, an output filter circuit 14, an optoelectronic isolation feedback circuit 15, a PWM control circuit 16, a power supply circuit 17, a thermistor circuit 18, a detection circuit 19, and an output terminal 20. The input filter circuit 12 includes an EMC filter (electromagnetic compatibility filter) circuit 121 and a rectifier filter circuit 122. The transformer circuit 13 includes a power switch and a high-frequency isolation transformer circuit. The detection circuit is used to compensate for overcurrent of the input high / low voltage.

[0025] Specifically, the input end 11 of the power supply is connected to the EMC filter circuit 121, the rectifier filter circuit 122, the transformer circuit 13, the output filter circuit 14, and the output end 20 in sequence; each control port of the PWM control circuit is connected to the power supply circuit 17, the optoelectronic isolation feedback circuit 15, the thermistor circuit 18, and the detection circuit 19 respectively.

[0026] Exemplarily, the PWM control circuit includes a power management chip U1. For example, the power management chip may be an LD5760EGR power management chip.

[0027] For example, the first control port of the power management chip U1 is connected to the thermistor circuit; the second control port of the power management chip U1 is connected to the detection circuit and the first end of the optoelectronic isolation feedback circuit; the fifth control port of the power management chip U1 is connected to the transformer circuit; the power supply circuit is connected to the sixth control port of the power management chip U1; the second end of the optoelectronic isolation feedback circuit is connected to the output filter circuit. The eighth control port of the power management chip U1 is connected to the EMC filter circuit and the rectifier filter circuit. The transformer circuit is connected to the power supply circuit.

[0028] Exemplary, reference Figure 2 As shown, the thermistor circuit 18 includes a resistor RJ2, a thermistor RT2, and a resistor R27 connected in series, wherein one end of the resistor RJ2 is connected to the first control port of the power management chip U1; and one end of the resistor R27 is connected to the ground.

[0029] Exemplary, reference Figure 3 As shown, the detection circuit includes: a resistor R71, a resistor R72, a resistor R74, a resistor R75, a filter electrolytic capacitor C33, and a transistor Q10.

[0030] The second control port of the power management chip U1 is connected to the first end of the resistor R71, the second end of the resistor R71 is connected to the first end of the resistor R72, the first end of the filter electrolytic capacitor C33, and the base of the transistor Q10; the second end of the resistor R72 and the second end of the filter electrolytic capacitor C33 are connected to the ground end; the emitter of the transistor Q10 is connected to the third control port of the power management chip U1; the collector of the transistor Q10 is connected to the first end of the resistor R75, the second end of the resistor R75 is connected to the first end of the resistor R74, and the second end of the resistor R74 is connected to the output end (BUS port) of the rectifier and filter circuit.

[0031] Exemplary, reference Figure 3 As shown, the EMC filter circuit includes: an inductor L1, an inductor L2, a filter capacitor CX1, a winding resistor RX1, a winding resistor RX2, a winding resistor RX3, and a winding resistor RX4.

[0032] Specifically, the first end of the input switch is connected in series with the fuse F1 and the thermistor NTC1 in sequence, and the two ends of the varistor VDR1 are connected to the thermistor NTC1 and the third end of the input switch, respectively. After the winding resistor RX1 is connected in series with the winding resistor RX4, and the winding resistor RX2 is connected in series with the winding resistor RX3, they are connected in parallel to realize mixed resistance, and are connected in parallel with the filter capacitor CX1 between the inductor L1 and the inductor L2. The first end of the inductor L2 is connected in series with the diode D9, the resistor R60, and the resistor R59, and then connected to the eighth control port (HV) of the power management chip U1. The second end of the inductor L2 is connected in series with the resistor R60 and the resistor R59 through the diode D12, and then connected to the eighth control port (HV) of the power management chip U1. After the first and second ends of the inductor L2 are connected in series with the rectifier and filter circuit, they are connected to the power switch tube and the high-voltage isolation transformer circuit.

[0033] Exemplary, reference Figure 3 As shown, the power supply circuit includes: capacitor C6, diode D2, resistor R17, and capacitor V7. Specifically, the sixth control port (VCC) of the power management chip U1 is connected to the first end of capacitor C6 and the cathode of diode D2. The second end of capacitor C6 is connected to the second end of capacitor C7 and then to ground. The anode of diode D2 is connected to the first end of resistor R17, and the second end of resistor R17 is connected to the first end of capacitor C7 and port T1. Port T1 is connected to the T1 port of the output rectifier and filter circuit. Capacitor C7 is connected in parallel with the power switch tube and the transformer of the high-frequency isolation transformer circuit.

[0034] Exemplary, reference Figure 3 As shown, the photoelectric isolation feedback circuit includes: resistor R13, resistor R14, resistor R15, resistor R19, resistor R24, resistor R24, potentiometer PC1, capacitor C14, Zener diode U2, and Zener diode ZD2.

[0035] Specifically, refer to Figure 3 As shown, the second control port (COMP) of the power management chip U1 is connected in series with resistor R19 and then connected to the collector of the transistor in potentiometer PC1. The emitter of the transistor is connected to ground. After the light-emitting diode in potentiometer PC1 is connected in parallel with resistor R13, its positive electrode is connected in series with resistor R15 and Zener diode ZD2 and then connected to the output rectifier and filter circuit. Its negative electrode is connected to the first end of capacitor C14 and the negative electrode of Zener diode U2. The second end of capacitor C14 is connected to the second end of resistor R16, the first end of resistor R24, the first end of resistor R25, and the negative electrode of Zener diode U2. The second end of resistor R25, the second end of resistor R24, and the negative electrode of Zener diode U2 are connected to ground. The negative electrode of Zener diode ZD2 is connected to the output rectifier and filter circuit and the first end of resistor R16.

[0036] For example, the power switch tube and high frequency isolation transformer circuit includes an isolation transformer component and a power switch tube component, and is connected to the fifth control port (DRV) of the power management chip U1; the specific circuit structure is as follows: Figure 3 shown.

[0037] In the power control circuit of the present invention, the second control port (COMP) of the power management chip U1 is connected to resistors R71, R72, and C33, and then to the base of transistor Q10. One end of resistor R74 is connected to the positive electrode of input filter electrolytic capacitor C3, and the other end is connected to resistor R75. The other end of resistor R75 is connected to the collector of transistor Q10, and the emitter of transistor Q10 is connected to the third control port (CS) of the power management chip U1, providing different compensation currents for high and low voltage inputs. When the main power supply is unloaded, the voltage at the second control port of the power management chip U1 is less than 1.8V, causing transistor Q10 to be cut off. The overcurrent compensation resistors R74 and R75 are equivalent to an open circuit. At this time, the overcurrent compensation resistors R74 and R75 are not activated, and no power is consumed. When the output load increases to more than 3A, the voltage at the second control port of the power management chip U1 is greater than 2.5V, and transistor Q10 is turned on, activating the high and low voltage compensation circuits. At this time, consistency of the overcurrent protection points of the high and low voltage inputs can be achieved.

[0038] For example, this circuit implements a flyback topology design by using a power management chip with an X-capacitor discharge function, achieving a full-voltage input to achieve low standby power consumption and a power supply with consistent overcurrent protection points. By detecting the voltage on the voltage feedback control pin (COMP) of the power management chip, the power supply's no-load and loaded operating states are distinguished. When the output is no-loaded, the COMP output voltage is approximately 1.7V, and when the output is loaded with a 3A load, the COMP output voltage is >2.5V. The difference in no-load and loaded COMP output voltages is used to control the on and off of the overcurrent high and low input compensation circuits. When the output is no-loaded, the high and low voltage compensation circuits are turned off, and when the output loaded current is greater than a certain set value, the high and low voltage compensation circuits are turned on, achieving the low standby power consumption power supply requirements with high and low overcurrent compensation.

[0039] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow from the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the claims.

[0040] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A power supply control circuit, characterized in that: The power supply control circuit includes: an input filter circuit, a transformer circuit, an output filter circuit, a PWM control circuit, a photoelectric isolation feedback circuit, a power supply circuit, a thermistor circuit, and a detection circuit; wherein the detection circuit is used to perform overcurrent compensation for the input high / low voltage; The input filter circuit is connected to the power input terminal, and is sequentially connected to the transformer circuit, the output filter circuit, and the power output terminal; The PWM control circuit includes: a power management chip U1; a first control port of the power management chip U1 is connected to the thermistor circuit; a second control port of the power management chip U1 is connected to the detection circuit and the first end of the photoelectric isolation feedback circuit; a fifth control port of the power management chip U1 is connected to the transformer circuit; the power supply circuit is connected to the sixth control port of the power management chip U1; and the second end of the photoelectric isolation feedback circuit is connected to the output filter circuit.

2. The power supply control circuit according to claim 1, wherein: The detection circuit includes: a resistor R71, a resistor R72, a resistor R74, a resistor R75, a filter electrolytic capacitor C33, and a transistor Q10; The second control port of the power management chip U1 is connected to the first end of the resistor R71, the second end of the resistor R71 is connected to the first end of the resistor R72, the first end of the filter electrolytic capacitor C33, and the base of the transistor Q10; the second end of the resistor R72 and the second end of the filter electrolytic capacitor C33 are connected to the ground end; the emitter of the transistor Q10 is connected to the third control port of the power management chip U1; the collector of the transistor Q10 is connected to the first end of the resistor R75, the second end of the resistor R75 is connected to the first end of the resistor R74, and the second end of the transistor R74 is connected to the input filter circuit.

3. The power supply control circuit according to claim 1, wherein: The input filter circuit includes an EMC filter circuit and a rectifier filter circuit connected in sequence; wherein the EMC filter circuit is connected to the power input end; and the rectifier filter circuit is connected to the input end of the transformer circuit.

4. The power supply control circuit according to claim 3, wherein: The eighth control port of the power management chip U1 is connected to the EMC filter circuit and the rectifier filter circuit.

5. The power control circuit according to claim 1, wherein: The transformer circuit is connected to the power supply circuit.

6. The power supply control circuit according to claim 1 or 5, characterized in that: The transformer circuit includes a power switch tube and a high-frequency isolation transformer circuit.

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