CN219204363U

CN219204363U - Switching power supply constant current circuit and switching power supply

Info

Publication number: CN219204363U
Application number: CN202320119457.9U
Authority: CN
Inventors: 赵凯鹏; 唐继魁; 何浩; 昃萌
Original assignee: Guangzhou Mingde Power Technology Co ltd
Current assignee: Guangzhou Mingde Power Technology Co ltd
Priority date: 2023-01-12
Filing date: 2023-01-12
Publication date: 2023-06-16
Anticipated expiration: 2033-01-12

Abstract

The utility model discloses a constant-current circuit of a switching power supply and the switching power supply, which comprise a flyback energy conversion circuit, an output rectifying and filtering circuit, a constant-voltage control circuit and a constant-current control circuit, wherein the flyback energy conversion circuit is connected with the output rectifying and filtering circuit, the output rectifying and filtering circuit is connected with the constant-voltage control circuit, and the flyback energy conversion circuit is wirelessly connected with the constant-voltage control circuit.

Description

Switching power supply constant current circuit and switching power supply

Technical Field

The utility model relates to the technical field of switching power supplies, in particular to a switching power supply constant current circuit and a switching power supply.

Background

In a power electronic system, a constant-voltage output switching power supply is mostly adopted to supply power to the system, but the starting of the constant-voltage output switching power supply is difficult and even abnormal due to larger capacitive load, so that the stability and reliability of the power supply of the whole system are affected; meeting the capacity of carrying a large capacitive load, a buffer circuit is additionally added to adjust the starting time sequence, so that the cost is increased.

Disclosure of Invention

In order to solve the problems of the switching power supply, the utility model designs a switching power supply constant current circuit and a switching power supply, and the switching power supply has the functions of input undervoltage protection and output overcurrent short-circuit protection, and particularly has reliable and stable starting when in a large capacitive load, and the specific technical scheme is as follows:

the utility model provides a switching power supply constant current circuit and switching power supply, includes flyback energy conversion circuit, output rectification filter circuit, constant voltage control circuit, constant current control circuit, flyback energy conversion circuit connects output rectification filter circuit, output rectification filter circuit connects constant voltage control circuit, output rectification filter circuit connects constant current control circuit, flyback energy conversion circuit and constant voltage control circuit wireless connection.

Preferably, the flyback energy conversion circuit includes a dc input positive electrode Vin, a dc input negative electrode GND, a resistor R0, a resistor R1, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a capacitor C3, a capacitor C11, a capacitor C12, a capacitor C13, a capacitor C14, a capacitor C15, a capacitor C16, a capacitor C20, a diode D4, a zener diode VZ1, a switching tube VM1, a high-frequency transformer T1, an optocoupler receiving tube U2A, and a flyback control chip U1; the high-frequency transformer T1 is characterized in that the 8 pin of the high-frequency transformer T1 is connected with a direct current input positive pole Vin, the 12 pin of the high-frequency transformer T1 is connected with the 2 pin of the switch tube VM1, the 3 pin of the switch tube VM1 is connected with one end of a resistor R1, the other end of the resistor R1 is connected with a direct current input negative pole GND, the resistor R0 is connected with a capacitor C3 in parallel, one end of the resistor R0 is connected with the 8 pin of the high-frequency transformer T1, the other end of the resistor R0 is connected with the 12 pin of the high-frequency transformer T1 through a diode D4, one end of the resistor R16 is connected with the 1 pin of the switch tube VM1, the other end of the resistor R16 is connected with the 3 pin of the switch tube VM1, one end of the resistor R11 is connected with the direct current input positive pole Vin, the other end of the resistor R11 is connected with a direct current input negative pole GND through a voltage stabilizing diode VZ1, the capacitor C11, the capacitor C12 and the voltage stabilizing diode VZ1 are connected in parallel, and the diode Z1 is connected with the flyback control chip U1.

Further, the cathode of the zener diode VZ1 is connected with the 7 pin of the flyback control chip U1, the 5 pin of the flyback control chip U1 is connected with the direct current input negative pole GND, the 2 pin of the flyback control chip U1 is connected with the direct current input negative pole GND, the 1 pin of the flyback control chip U1 is connected with the 8 pin of the flyback control chip U1 through the resistor R15, the 8 pin of the flyback control chip U1 is connected with the 4 pin of the flyback control chip U1 through the resistor R14, the 4 pin of the flyback control chip U1 is connected with the direct current input negative pole GND through the capacitor C14, the 4 pin of the flyback control chip U1 is connected with the 3 pin of the flyback control chip U1 through the capacitor C15, the 3 pin of the flyback control chip U1 is connected with the 3 pin of the switch tube VM1 through the resistor R13, the 6 pin of the flyback control chip U1 is connected with the 3 pin of the flyback control chip U1 through the resistor R12, and the 4 pin of the flyback control chip is connected with the direct current input negative pole GND through the capacitor C1, and the 3 pin of the flyback control chip U1 is connected with the negative pole GND.

Preferably, the output rectifying and filtering circuit comprises a rectifying diode D1, a rectifying diode D2, a filtering capacitor C1, a filtering capacitor C2, a capacitor C8, a resistor R3, a resistor R4, a resistor R17, a piezoresistor RV1, a rectifying output ground GND1, a direct current output positive pole Vout, and a direct current output negative pole GND2, the rectifying diode D1 and the rectifying diode D2 are connected in series, the positive pole of the rectifying diode D1 is connected with a flyback energy conversion circuit, the negative pole of the rectifying diode D2 is connected with a direct current output positive pole Vout, the negative pole of the rectifying diode D2 is connected with a rectifying output ground GND1 through the filtering capacitor C1, the negative pole of the rectifying diode D2 is connected with the direct current output negative pole GND2 through the filtering capacitor C2, one end of the resistor R17 is connected with the positive pole of the rectifying diode D1, the other end of the resistor R17 is connected with the capacitor C8, the other end of the resistor R8 is connected with the negative pole of the rectifying diode D2, one end of the piezoresistor RV1 is connected with the direct current output positive pole Vout, the other end of the resistor RV is connected with the direct current output negative pole GND2 through the resistor R3.

Preferably, the constant voltage control circuit includes a rectifier diode D3, a filter capacitor C4, a filter capacitor C5, a capacitor C21, a capacitor C22, a resistor R8, a resistor R9, a resistor R10, a resistor R20, a resistor R21, a resistor R22, an optocoupler emission tube U2B, a reference voltage chip U3, and a rectification output ground GND1, wherein an anode of the rectifier diode D3 is connected to the flyback energy conversion circuit, a cathode of the rectifier diode D3 is connected to the rectification output ground GND1 through the filter capacitor C4, the filter capacitor C4 and the filter capacitor C5 are connected in parallel, a cathode of the rectifier diode D3 is connected to a pin 1 of the optocoupler emission tube U2B through a resistor R20, a cathode of the rectifier diode D3 is connected to a pin 2 of the optocoupler emission tube U2B through a resistor R21, a pin 2 of the reference voltage chip U3 is connected to the reference voltage chip U3, a pin 3 of the reference voltage chip U3 is connected to the rectification output ground GND1, a cathode of the rectifier diode D3 is connected to the reference voltage chip C3 through a pin 2, and a resistor R2 is connected to one end of the reference voltage chip R2 through a resistor R8, and the other end of the rectifier diode D2 is connected to the reference voltage chip R2 through a resistor R8.

Preferably, the constant current control circuit includes a zener diode VZ2, a zener diode VZ3, a capacitor C6, a capacitor C7, a resistor R2, a resistor R5, a resistor R6, a resistor R7, a switch tube VM2, a reference voltage chip U4, a rectification output ground GND1, a direct current output negative pole GND2, one end of the resistor R5 is connected with an output rectification filter circuit, the other end of the resistor R5 is connected with a 1 pin of the switch tube VM2 through the resistor R6, a 2 pin of the switch tube VM2 is connected with the direct current output negative pole GND2, the capacitor C6 is connected with the zener diode VZ2 in parallel, a cathode of the zener diode VZ2 is connected with a 1 pin of the switch tube VM2, an anode of the zener diode VZ2 is connected with a 3 pin of the switch tube VM2, a 3 pin of the reference voltage chip U4 is connected with the rectification output ground GND1, a 3 pin of the reference voltage chip U4 is connected with a 2 pin of the reference voltage chip U4 through the capacitor C7, a 2 pin of the reference voltage chip U4 is connected with the resistor R7, and the cathode of the switch tube VZ2 is connected with the cathode of the switch tube VZ 2.

Compared with the prior art, the utility model has the beneficial effects that:

1. the utility model can output stable constant current and constant voltage, and meets the requirement of stable and reliable starting with large capacitive load;

2. the circuit scheme of the utility model has the advantages of simple used devices, low cost, high cost performance and good practicability and economy;

3. the utility model has stable performance, easy parameter adjustment, realization of input under-voltage protection function, output over-current short-circuit protection function, better voltage and load adjustment rate, smaller temperature drift and high efficiency.

Drawings

Fig. 1 is a schematic diagram of a circuit connection structure according to the present utility model.

In the figure: 1. a flyback energy conversion circuit; 2. an output rectifying and filtering circuit; 3. a constant voltage control circuit; 4. and a constant current control circuit.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

Referring to fig. 1, an embodiment of the present utility model is as follows:

as shown in a circuit schematic diagram of the utility model in fig. 1, a switching power supply constant current circuit and a switching power supply comprise a flyback energy conversion circuit 1, an output rectifying and filtering circuit 2, a constant voltage control circuit 3 and a constant current control circuit 4, wherein the flyback energy conversion circuit 1 is connected with the output rectifying and filtering circuit 2, the output rectifying and filtering circuit 2 is connected with the constant voltage control circuit 3, the output rectifying and filtering circuit 2 is connected with the constant current control circuit 4, and the flyback energy conversion circuit 1 is in wireless connection with the constant voltage control circuit 3.

As shown in fig. 1, the flyback energy conversion circuit 1 includes a dc input positive electrode Vin, a dc input negative electrode GND, a resistor R0, a resistor R1, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a capacitor C3, a capacitor C11, a capacitor C12, a capacitor C13, a capacitor C14, a capacitor C15, a capacitor C16, a capacitor C20, a diode D4, a zener diode VZ1, a switching tube VM1, a high-frequency transformer T1, an optocoupler receiving tube U2A, and a flyback control chip U1; the high-frequency transformer T1 is connected with a direct-current input positive pole Vin at the 8 pin, the high-frequency transformer T1 is connected with the 2 pin of a switching tube VM1 at the 12 pin, the switching tube VM1 is connected with one end of a resistor R1 at the 3 pin, the other end of the resistor R1 is connected with a direct-current input negative pole GND, the resistor R0 is connected with a capacitor C3 in parallel, one end of the resistor R0 is connected with the 8 pin of the high-frequency transformer T1, the other end of the resistor R0 is connected with the 12 pin of the high-frequency transformer T1 through a diode D4, one end of the resistor R16 is connected with the 1 pin of the switching tube VM1, the other end of the resistor R16 is connected with the 3 pin of the switching tube VM1, one end of the resistor R11 is connected with the direct-current input negative pole GND through a voltage stabilizing diode VZ1, the capacitor C11, the capacitor C12 and the voltage stabilizing diode VZ1 are connected in parallel, the cathode of the diode Z1 is connected with the pin 7 of a flyback control chip U1, the other end of the resistor R0 is connected with the flyback control chip U1 through the 3 pin of the diode C1, the flyback chip is connected with the 3 pin of the flyback chip U1 through the 3, the 3 pin of the flyback chip is connected with the 3 through the resistor R1, the flyback chip through the 3U 1 is connected with the 3 pin of the 3, the flyback chip through the 3, the flyback chip is connected with the 3 through the 3 pin of the 3 chip through the 3, and the flyback chip through the 3, and the 3 is connected with the 3 through the flyback chip through the voltage stabilizing diode VZ1, the 1 foot of flyback control chip U1 passes through electric capacity C16 and connects direct current input negative pole GND, the 4 feet of opto-coupler receiver tube U2A are connected to 1 foot of flyback control chip U1, the 3 feet of opto-coupler receiver tube U2A connect direct current input negative pole GND.

As shown in fig. 1, the output rectifying and filtering circuit 2 includes a rectifying diode D1, a rectifying diode D2, a filter capacitor C1, a filter capacitor C2, a capacitor C8, a resistor R3, a resistor R4, a resistor R17, a piezoresistor RV1, a rectifying output ground GND1, a direct current output positive electrode Vout, and a direct current output negative electrode GND2, the rectifying diode D1 and the rectifying diode D2 are connected in series, the positive electrode of the rectifying diode D1 is connected to the flyback energy conversion circuit 1, the negative electrode of the rectifying diode D2 is connected to the direct current output positive electrode Vout, the negative electrode of the rectifying diode D2 is connected to the rectifying output ground GND1 through the filter capacitor C1, the negative electrode of the rectifying diode D2 is connected to the direct current output negative electrode GND2 through the filter capacitor C2, one end of the resistor R17 is connected to the positive electrode of the rectifying diode D1, the other end of the resistor R17 is connected to the capacitor C8, the other end of the resistor C8 is connected to the negative electrode of the rectifying diode D2, one end of the piezoresistor RV1 is connected to the direct current output positive electrode Vout, and the other end of the resistor R3 is connected to the direct current output negative electrode GND2 through the filter capacitor R2.

As shown in fig. 1, the constant voltage control circuit 3 includes a rectifying diode D3, a filter capacitor C4, a filter capacitor C5, a capacitor C21, a capacitor C22, a resistor R8, a resistor R9, a resistor R10, a resistor R20, a resistor R21, a resistor R22, an optocoupler emission tube U2B, a reference voltage chip U3, and a rectifying output ground GND1, wherein an anode of the rectifying diode D3 is connected to the flyback energy conversion circuit 1, a cathode of the rectifying diode D3 is connected to the rectifying output ground GND1 through the filter capacitor C4, the filter capacitor C4 and the filter capacitor C5 are connected in parallel, a cathode of the rectifying diode D3 is connected to a pin 1 of the optocoupler emission tube U2B through a resistor R20, a cathode of the rectifying diode D3 is connected to a pin 2 of the optocoupler emission tube U2B through a resistor R21, a pin 2 of the optocoupler emission tube U2B is connected to a pin 1 of the reference voltage chip U3, a pin 3 of the reference voltage chip U3 is connected to the rectifying output ground GND1, a cathode of the rectifying diode D3 is connected to the reference voltage chip U2C 2 is connected to the reference voltage chip C2 through a pin 2, and a pin 2 of the reference voltage chip R2 is connected to one end of the resistor R2 is connected to the reference voltage chip 2R 2 through a resistor R8.

As shown in fig. 1, the constant current control circuit 4 includes a voltage stabilizing diode VZ2, a voltage stabilizing diode VZ3, a capacitor C6, a capacitor C7, a resistor R2, a resistor R5, a resistor R6, a resistor R7, a switch tube VM2, a reference voltage chip U4, a rectification output ground GND1, and a direct current output negative electrode GND2, one end of the resistor R5 is connected with the output rectification filter circuit 2, the other end of the resistor R5 is connected with a 1 pin of the switch tube VM2 through the resistor R6, a 2 pin of the switch tube VM2 is connected with the direct current output negative electrode GND2, the capacitor C6 is connected with the voltage stabilizing diode VZ2 in parallel, a cathode of the voltage stabilizing diode VZ2 is connected with the 1 pin of the switch tube VM2, an anode of the voltage stabilizing diode VZ2 is connected with the 3 pin of the switch tube VM2, the 3 pin of the reference voltage chip U4 is connected with the rectification output ground GND1, the 3 pin of the reference voltage chip U4 is connected with the reference voltage chip U4 through the capacitor C7, and the voltage stabilizing diode VZ2 is connected with the 3 pin of the switch tube VM 2.

The utility model adopts the reference voltage chip and the resistor to construct the constant current charging circuit, and is matched with the power-on delay circuit formed by the switching tubes, thereby improving the capacity of the switching power supply with large capacitive load and increasing the stability and reliability of the starting of the switching power supply.

It will be evident to those skilled in the art that the utility model is not limited to the details of the foregoing illustrative embodiments, and that the present utility model may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the utility model being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims

1. The utility model provides a switching power supply constant current circuit and switching power supply, its characterized in that includes flyback energy conversion circuit (1), output rectification filter circuit (2), constant voltage control circuit (3), constant current control circuit (4), flyback energy conversion circuit (1) connect output rectification filter circuit (2), constant voltage control circuit (3) are connected to output rectification filter circuit (2), constant current control circuit (4) are connected to output rectification filter circuit (2), flyback energy conversion circuit (1) and constant voltage control circuit (3) wireless connection.

2. The switching power supply constant current circuit and the switching power supply according to claim 1, wherein the flyback energy conversion circuit (1) comprises a direct current input positive electrode Vin, a direct current input negative electrode GND, a resistor R0, a resistor R1, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a capacitor C3, a capacitor C11, a capacitor C12, a capacitor C13, a capacitor C14, a capacitor C15, a capacitor C16, a capacitor C20, a diode D4, a zener diode VZ1, a switching tube VM1, a high-frequency transformer T1, an optocoupler receiving tube U2A, and a flyback control chip U1; the high-frequency transformer T1 is characterized in that the 8 pin of the high-frequency transformer T1 is connected with a direct current input positive pole Vin, the 12 pin of the high-frequency transformer T1 is connected with the 2 pin of the switch tube VM1, the 3 pin of the switch tube VM1 is connected with one end of a resistor R1, the other end of the resistor R1 is connected with a direct current input negative pole GND, the resistor R0 is connected with a capacitor C3 in parallel, one end of the resistor R0 is connected with the 8 pin of the high-frequency transformer T1, the other end of the resistor R0 is connected with the 12 pin of the high-frequency transformer T1 through a diode D4, one end of the resistor R16 is connected with the 1 pin of the switch tube VM1, the other end of the resistor R16 is connected with the 3 pin of the switch tube VM1, one end of the resistor R11 is connected with the direct current input positive pole Vin, the other end of the resistor R11 is connected with a direct current input negative pole GND through a voltage stabilizing diode VZ1, the capacitor C11, the capacitor C12 and the voltage stabilizing diode VZ1 are connected in parallel, and the diode Z1 is connected with the flyback control chip U1.

3. The switching power supply constant current circuit and the switching power supply according to claim 2, wherein the cathode of the zener diode VZ1 is connected to the 7 pin of the flyback control chip U1, the 5 pin of the flyback control chip U1 is connected to the 3 pin of the flyback control chip U1 through the capacitor C15, the 1 pin of the flyback control chip U1 is connected to the 8 pin of the flyback control chip U1 through the resistor R15, the 8 pin of the flyback control chip U1 is connected to the 4 pin of the flyback control chip U1 through the resistor R14, the 4 pin of the flyback control chip U1 is connected to the 3 pin of the flyback control chip U1 through the capacitor C14, the 3 pin of the flyback control chip U1 is connected to the 3 pin of the flyback control chip U1 through the capacitor C13, the 3 pin of the flyback control chip U1 is connected to the 8 pin of the flyback control chip U1 through the resistor R13, the 4 pin of the flyback control chip U1 is connected to the 3 pin of the flyback control chip U1 through the capacitor C12, and the 3 pin of the flyback control chip U1 is connected to the 3 pin of the flyback control chip U1 through the capacitor C1 is connected to the 3 pin of the negative resistor VM 1.

4. The switching power supply constant current circuit and the switching power supply according to claim 1, wherein the output rectifying and filtering circuit (2) comprises a rectifying diode D1, a rectifying diode D2, a filtering capacitor C1, a filtering capacitor C2, a capacitor C8, a resistor R3, a resistor R4, a resistor R17, a piezoresistor RV1, a rectifying output ground GND1, a direct current output positive pole Vout and a direct current output negative pole GND2, the rectifying diode D1 and the rectifying diode D2 are connected in series, the positive pole of the rectifying diode D1 is connected with a flyback energy conversion circuit (1), the negative pole of the rectifying diode D2 is connected with a direct current output positive pole Vout, the negative pole of the rectifying diode D2 is connected with a rectifying output ground GND1 through the filtering capacitor C1, the negative pole of the rectifying diode D2 is connected with a direct current output negative pole GND2 through the filtering capacitor C2, one end of the resistor R17 is connected with the positive pole of the rectifying diode D1, the other end of the resistor R17 is connected with the capacitor C8, the other end of the rectifying diode D8 is connected with the other end of the rectifying diode D2 is connected with the positive pole RV, the other end of the resistor R2 is connected with the direct current output negative pole of the direct current output positive pole of the resistor R3, and the other end of the resistor RV is connected with the direct current output negative pole of the resistor R2 is connected with the positive pole of the direct current output voltage resistor 3.

5. The constant current circuit of a switching power supply and the switching power supply according to claim 1, wherein the constant voltage control circuit (3) comprises a rectifying diode D3, a filter capacitor C4, a filter capacitor C5, a capacitor C21, a capacitor C22, a resistor R8, a resistor R9, a resistor R10, a resistor R20, a resistor R21, a resistor R22, an optocoupler emission tube U2B, a reference voltage chip U3, a rectifying output ground GND1, wherein the positive electrode of the rectifying diode D3 is connected with the flyback energy conversion circuit (1), the negative electrode of the rectifying diode D3 is connected with the rectifying output ground GND1 through the filter capacitor C4, the filter capacitor C4 is connected with the filter capacitor C5 in parallel, the negative electrode of the rectifying diode D3 is connected with the 1 pin of the optocoupler emission tube U2B through the resistor R20, the negative pole of rectifier diode D3 passes through 2 feet of resistance R21 connection opto-coupler emission pipe U2B, reference voltage chip U3's 1 foot is connected to opto-coupler emission pipe U2B's 2 feet, reference voltage chip U3's 3 feet connect rectification output ground GND1, reference voltage chip U3's 2 feet pass through electric capacity C21 and connect reference voltage chip U3's 1 foot, reference voltage chip U3's 2 feet pass through electric capacity C22 and connect resistance R22's one end, reference voltage chip U3's 1 foot is connected to resistance R22's the other end, resistance R8 and resistance R9 are established ties mutually, output rectification filter circuit (2) are connected to resistance R8's one end, resistance R9 connects reference voltage chip U3's 2 feet, reference voltage chip U3's 2 feet pass through resistance R10 and connect rectification output ground GND1.

6. The constant current circuit and the switching power supply according to claim 1, wherein the constant current control circuit (4) comprises a zener diode VZ2, a zener diode VZ3, a capacitor C6, a capacitor C7, a resistor R2, a resistor R5, a resistor R6, a resistor R7, a switching transistor VM2, a reference voltage chip U4, a rectifying output ground GND1, and a direct current output negative GND2, one end of the resistor R5 is connected to an output rectifying filter circuit (2), the other end of the resistor R5 is connected to a pin 1 of the switching transistor VM2 through the resistor R6, a pin 2 of the switching transistor VM2 is connected to a direct current output negative GND2, the capacitor C6 is connected to the zener diode VZ2 in parallel, an anode of the zener diode VZ2 is connected to a pin 1 of the switching transistor VM2, a pin 3 of the reference voltage chip U4 is connected to a rectifying output ground GND1, a pin 3 of the reference voltage chip U4 is connected to a pin 3 of the switching transistor VM 4 through the capacitor C4, and a pin 3 of the switching transistor VZ2 is connected to the reference voltage chip v 2 is connected to the pin 3 of the switching transistor VM2 through the resistor VM 2.