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CN-122000832-A - Self-recovery protection circuit for output short circuit of direct-current stabilized power supply and design method

CN122000832ACN 122000832 ACN122000832 ACN 122000832ACN-122000832-A

Abstract

The invention discloses a self-recovery protection circuit for a direct current stabilized power supply output short circuit, which comprises a voltage detection circuit and a voltage maintenance circuit, wherein signals of the voltage detection circuit and the voltage maintenance circuit enter a voltage comparison circuit, signals of the voltage comparison circuit enter a short circuit signal generation circuit, the short circuit signal generation circuit is connected with a pulse timing circuit and a short circuit recovery signal generation circuit, and signals of the short circuit recovery signal generation circuit enter the voltage comparison circuit And 4) selecting a voltage division network of the short-circuit recovery signal generation circuit. The invention can greatly improve the safety performance of the circuit and has the characteristic of timely and effectively carrying out output short-circuit protection on the stabilized power supply.

Inventors

  • ZHONG MINGHANG

Assignees

  • 西安理工大学

Dates

Publication Date
20260508
Application Date
20260127

Claims (10)

  1. 1. The self-recovery protection circuit for the output short circuit of the direct-current stabilized power supply is characterized by comprising a voltage detection circuit (2) and a voltage maintenance circuit (1), wherein signals of the voltage detection circuit (2) and the voltage maintenance circuit (1) enter a voltage comparison circuit (3), signals of the voltage comparison circuit (3) enter a short circuit signal generation circuit (6), the short circuit signal generation circuit (6) is connected with a pulse timing circuit (5) and a short circuit recovery signal generation circuit (4), and signals of the short circuit recovery signal generation circuit (4) enter the voltage comparison circuit (3).
  2. 2. The self-recovery protection circuit for a dc stabilized power supply output short circuit according to claim 1, wherein the voltage maintaining circuit (1) includes a diode D1 and a capacitor C1, the positive electrode of the diode D1 is connected to the positive electrode of the circuit, the negative electrode of the diode D1 is connected to the capacitor C1, the other end of the capacitor C1 is connected to the negative electrode of the circuit, the voltage maintaining circuit (1) further includes a resistor R5 and a resistor R7, the left end of the resistor R5 is connected between the diode D1 and the capacitor C1, the right end of the resistor R5 is connected to the upper end of the resistor R7, and the lower end of the resistor R7 is connected to the negative electrode of the circuit.
  3. 3. The self-recovery protection circuit for the output short circuit of the direct current stabilized power supply according to claim 1, wherein the voltage detection circuit (2) comprises a resistor R2 and a resistor R8, the upper end of the resistor R2 is connected to the positive electrode of the circuit, the lower end of the resistor R2 is connected to the upper end of the resistor R8, and the lower end of the resistor R8 is connected to the negative electrode of the circuit.
  4. 4. The self-recovery protection circuit for a dc regulated power supply output short circuit according to claim 1, wherein the voltage comparison circuit (3) comprises a comparator U1, an input IN-of the comparator U1 is connected between a resistor R5 and a resistor R7, an input in+ of the comparator U1 is connected between a resistor R2 and a resistor R8, and an output Vout of the comparator U1 is connected to a pin 2 of NE555 IN the short circuit signal generation circuit (6).
  5. 5. The self-recovery protection circuit for a dc stabilized power supply output short circuit according to claim 1, wherein the short-circuit recovery signal generating circuit (4) includes a diode D2, a resistor R9 and a resistor R10, an upper end of the resistor R9 is connected to a circuit of the resistor R6 and the capacitor C2, a lower end of the resistor R9 is connected to an upper end of the resistor R10, a lower end of the resistor R10 is grounded, an anode of the diode D2 is connected to a circuit between the resistor R9 and the resistor R10, a cathode of the diode D2 is connected to a circuit between the resistor R2 and the resistor R8, and a circuit connection point between the resistor R2 and the resistor R8 is closer than an input terminal in+ of the comparator U1.
  6. 6. The self-recovery protection circuit for output short circuit of a direct current stabilized power supply according to claim 1, wherein the pulse timing circuit (5) comprises a resistor R3 and a capacitor C3, the upper end of the resistor R3 is connected to the positive electrode of the circuit, the lower end of the resistor R3 is connected to the capacitor C3, and the other end of the capacitor C3 is connected to the negative electrode of the self-recovery protection circuit.
  7. 7. The self-recovery protection circuit for a dc regulated power supply output short circuit according to claim 4 or 5, wherein the short circuit signal generating circuit (6) further comprises a capacitor C4, a pin 3 of a NE555 outputs a high level, a pin 4 of the NE555 is connected to an upper end of the capacitor C2, a pin 5 of the NE555 is connected to an upper end of the capacitor C4, a lower end of the capacitor C4 is connected to a negative electrode of the self-recovery protection circuit, a pin 6 of the NE555 is connected to a lower end of a resistor R3, and a pin 7 of the NE555 is connected to a lower end of the resistor R3 and a connection position remote from the connection position of the pin 6.
  8. 8. The design method of the self-recovery protection circuit for the output short circuit of the direct current stabilized power supply according to any one of claims 1 to 7, characterized by comprising the following steps: step 1, selecting resistance and capacitance parameters in a voltage detection circuit (2); step2, selecting a comparator U1 parameter; step 3, selecting the time of the monostable trigger U2 to set the values of the resistor R3 and the capacitor C3, and determining the time of the monostable circuit to output high level ; And 4, selecting a voltage division network of the short-circuit recovery signal generation circuit (4).
  9. 9. The method for designing a self-recovery protection circuit for a dc voltage-stabilized power supply output short circuit according to claim 8, wherein the resistance and capacitance parameters selected in step 1 satisfy the formula: , Wherein V 1 is the voltage divided by the resistor R5 and the resistor R7, and V 2 is the voltage divided by the resistor R2 and the resistor R8; the parameters of the comparator U1 in the step 2 satisfy the following formula: , Where V cc is the supply voltage, U oH identifies an active high level for NE555, I oH is the leakage current at the high level of NE555, and I oL is the maximum current sink of the comparator.
  10. 10. The method for designing a self-recovery protection circuit for a dc voltage-stabilized power supply output short circuit according to claim 8, wherein the output high level time of the monostable trigger U2 and the parameters of the resistor R3 and the capacitor C3 in the step 3 satisfy the following formulas: , in the formula, The time of outputting the high level for the monostable flip-flop U2; The parameters of the circuit elements in the voltage dividing network in the step 4 satisfy the following formulas: , Wherein V 2 is the voltage divided by the resistor R2 and the resistor R8, and V 3 is the voltage divided by the resistor R9 and the resistor R10.

Description

Self-recovery protection circuit for output short circuit of direct-current stabilized power supply and design method Technical Field The invention belongs to the technical field of power supplies, and particularly relates to a self-recovery protection circuit for output short circuit of a direct-current stabilized power supply and a design method of the self-recovery protection circuit. Background The output short-circuit protection of the stabilized power supply is a troublesome problem possibly encountered by a linear power supply or a switching power supply in practical application, and how to effectively protect the short circuit in time is one content of the very necessary research. The power supply is used as a key part of the system, and plays a very important role in electronic equipment from daily electrical appliances such as mobile phones, computers and the like to equipment such as large-scale airplanes, ships and the like, and is generally divided into an alternating current power supply and a direct current power supply. The power supply provides reliable and stable working voltage for other working systems, and is in a normal working state in general, but in some abnormal operation or special application environments, output short circuit conditions can occur, so that very large short circuit current can be generated, and if the power supply cannot be timely protected, serious consequences such as power supply self-frying machine, burning back-stage system and the like can be generated, so that huge losses are caused. The DC voltage-stabilized power supply provides stable DC working voltage for the system, and is divided into a series voltage-stabilized power supply and a parallel voltage-stabilized power supply according to the connection mode of the voltage-stabilized power supply and a load, and is divided into a linear voltage-stabilized power supply and a switching voltage-stabilized power supply according to the working state of an adjusting tube, and is divided into a simple voltage-stabilized power supply, a feedback adjusting voltage-stabilized power supply and the like according to the adjusting mode. The current implementation mode of the direct current stabilized power supply with more applications is linear adjustment and switching power supply adjustment, the linear adjustment adjusts the output voltage through the adjustment pipeline characteristic, the direct current stabilized power supply has the advantages of small output voltage ripple, simple adjustment circuit, narrow output voltage adjustment range, limited output power and the like, the switching power supply converts the input voltage into high-frequency pulses through a Pulse Width Modulation (PWM) technology, and then the high-frequency pulses pass through an output filter circuit to obtain the required direct current voltage, and the direct current stabilized power supply has the advantages of flexible adjustment, wide output voltage range, high power density and the like, and also has the advantages of larger output ripple voltage, more complex parameter design and the like. The output short-circuit protection circuit is used in all-digital control power supply system, the equivalent resistance of the self-recovery fuse tube is changed and is not easy to carry out later stage matching, and the analog protection circuit has good application in the power supply of the analog-digital hybrid system due to the advantages of simple, stable and reliable circuit, but also has the problems of complex whole circuit and no self-recovery or poor self-recovery effect. Disclosure of Invention The invention aims to provide a self-recovery protection circuit for output short circuit of a direct-current stabilized power supply, which has the characteristic of timely and effectively carrying out output short circuit protection on the stabilized power supply. The invention also provides a design method of the self-recovery protection circuit for the output short circuit of the direct current stabilized power supply. The technical scheme adopted by the invention is that the self-recovery protection circuit for the output short circuit of the direct-current stabilized power supply comprises a voltage detection circuit and a voltage maintenance circuit, wherein signals of the voltage detection circuit and the voltage maintenance circuit enter a voltage comparison circuit, signals of the voltage comparison circuit enter a short circuit signal generation circuit, the short circuit signal generation circuit is connected with a pulse timing circuit and a short circuit recovery signal generation circuit, and signals of the short circuit recovery signal generation circuit enter the voltage comparison circuit. The invention is also characterized in that: The voltage maintaining circuit comprises a diode D1 and a capacitor C1, wherein the positive electrode of the diode D1 is connected with the positive electrode of the circuit, the negative