CN215221704U

CN215221704U - Overcurrent protection circuit with self-recovery function

Info

Publication number: CN215221704U
Application number: CN202120511124.1U
Authority: CN
Inventors: 徐东海; 刘建刚
Original assignee: Changzhou Wujin Hgpower Co ltd
Current assignee: Changzhou Hongguang Power Technology Co ltd
Priority date: 2021-03-10
Filing date: 2021-03-10
Publication date: 2021-12-17
Anticipated expiration: 2031-03-10

Abstract

The utility model relates to an overcurrent protection circuit with self-recovery function, which comprises an NA555 main circuit and an optical coupling switch circuit; the NA555 main body circuit is used for receiving the current signal OIP and the driving signal PWMAL output by the power control chip and outputting a corresponding level signal from an output end according to the received current signal OIP and the driving signal PWMAL; and the optical coupling switch circuit is connected with the output end of the NA555 main body circuit and used for acquiring a level signal and controlling a driving signal of the power MOS tube according to the level signal. The utility model aims at overcoming the defect that prior art exists, providing one kind and can protecting, can resume automatically and need not the overcurrent protection circuit of outage under the overcurrent state.

Description

Overcurrent protection circuit with self-recovery function

Technical Field

The utility model relates to a current protection and self recovery control field in the power field especially relate to a take overcurrent protection circuit of self recovery function.

Background

Most current protection is currently self-healing in hiccup mode or controlled by a single-chip microcomputer. The control of the current protection function in the hiccup mode is rough, and when the high-power supply is used, a switching tube is possibly damaged when the high-power supply is used for a long time; the singlechip control needs to add a singlechip and software writing work, and material and labor cost is increased. Therefore, it is necessary to design an over-current protection circuit which can protect under an over-current condition, can automatically recover and does not need to be powered off.

Disclosure of Invention

The utility model aims at overcoming the defect that prior art exists, providing one kind and can protecting, can resume automatically and need not the overcurrent protection circuit of outage under the overcurrent state.

Realize the utility model discloses the technical scheme of purpose is: an overcurrent protection circuit with a self-recovery function comprises an NA555 main body circuit and an optocoupler switch circuit; the NA555 main body circuit is used for receiving the current signal OIP and the driving signal PWMAL output by the power control chip and outputting a corresponding level signal from an output end according to the received current signal OIP and the driving signal PWMAL; and the optical coupling switch circuit is connected with the output end of the NA555 main body circuit and used for acquiring a level signal and controlling a driving signal of the power MOS tube according to the level signal.

Further, the optical coupling switch circuit comprises an optical coupling switch U1; the model of the optocoupler switch U1 is HCPL-4504.

Furthermore, while the pin No. 2 of the optocoupler switch U1 is connected with the output end of the NA555 main body circuit, the optocoupler switch U1 is grounded through a capacitor C4; the No. 7 pin and the No. 8 pin of the optocoupler switch U1 are connected with a 15V power supply connected with a filter capacitor C3; no. 6 pin of the optical coupling switch U1 is connected with the 15V power supply connected with the filter capacitor C3 through the resistor R3 on one path, is connected with the VN end on the other path, and is connected with the No. 5 pin of the optical coupling switch U1 through the capacitor C6 on one path and is grounded.

Further, the NA555 main body circuit comprises a NA555 chip; the trigger end of the NA555 chip is connected with the PWMAL end of the driving signal output by the power control chip through a diode V1 and a capacitor C5 in sequence; the positive end of the diode V1 is connected with a 5V power supply through a resistor R2; the negative terminal of the diode V1 is connected with a 5V power supply through a resistor R4.

Furthermore, one path of the threshold end of the NA555 chip is connected with the current signal OIP end through a resistor R5, one path of the threshold end is grounded through a capacitor C7, and the other path of the threshold end is connected with a 5V power supply through a resistor R1 and a resistor R1 in sequence; the resistor R1 is also connected with a resistor R14 in parallel; the resistor R1 and the resistor R1 are grounded through a capacitor C1.

Furthermore, the grounding end of the NA555 chip is grounded, the power supply end is connected with a 5V power supply with a filter capacitor C2, the reset end is connected with the 5V power supply, and the control voltage end is grounded through a capacitor C8.

After the technical scheme is adopted, the utility model discloses following positive effect has: the utility model discloses the simple circuit of accessible realizes power drive part's overcurrent protection function and can automatic recovery, need not the outage and reduces material and cost of labor. More specifically, the utility model discloses direct mos pipe through control power reaches protection circuit, and reaction rate is fast, can protect the mos pipe, can not have that kind of life-span's of relay problem, and the voltage spike is also very little, does not need additionally to increase the relay moreover, the cost is reduced.

Drawings

In order that the present invention may be more readily and clearly understood, the following detailed description of the present invention is given in conjunction with the accompanying drawings, in which

Fig. 1 is a circuit diagram of the present invention.

Detailed Description

As shown in fig. 1, the utility model comprises an NA555 main body circuit and an optical coupling switch circuit; the NA555 main body circuit is used for receiving the current signal OIP and the driving signal PWMAL output by the power control chip and outputting a corresponding level signal from an output end (namely a No. 3 pin and a Q end of the NA555 chip) according to the received current signal OIP and the driving signal PWMAL; the optical coupling switch circuit is connected with the output end of the NA555 main body circuit and used for acquiring a level signal and controlling a driving signal of a power MOS tube according to the level signal, namely VN in a circuit diagram.

More specifically in this embodiment, the optocoupler switch circuit includes an optocoupler switch U1; the model of the optocoupler switch U1 is HCPL-4504.

More specifically, in this embodiment, while the pin No. 2 of the optocoupler switch U1 is connected to the output terminal of the NA555 main circuit, it is also grounded through a capacitor C4; a No. 3 pin of the optocoupler switch U1 is connected with a PWMBL signal end, wherein PWMBL is also a driving signal and is a driving signal complementary with PWMAL; the No. 7 pin and the No. 8 pin of the optocoupler switch U1 are connected with a 15V power supply connected with a filter capacitor C3; no. 6 pin of the optical coupling switch U1 is connected with the 15V power supply connected with the filter capacitor C3 through the resistor R3 on one path, is connected with the VN end on the other path, and is connected with the No. 5 pin of the optical coupling switch U1 through the capacitor C6 on one path and is grounded.

More specifically, in this embodiment, the NA555 main body circuit includes a NA555 chip; the trigger end (namely a No. 2 pin and a TRIG end) of the NA555 chip is connected with the PWMAL end of a driving signal output by the power control chip through a diode V1 (from positive to negative) and a capacitor C5 in sequence; the positive end of the diode V1 is connected with a 5V power supply through a resistor R2; the negative terminal of the diode V1 is connected with a 5V power supply through a resistor R4.

More specifically, in this embodiment, one path of the threshold end (i.e., pin No. 6, THR end) of the NA555 chip is connected to the current signal OIP end through the resistor R5, one path is grounded through the capacitor C7, and the other path is connected to the 5V power supply through the resistor R × 1 and the resistor R1 in sequence; the resistor R1 is also connected with a resistor R14 in parallel; the resistor R1 and the resistor R1 are grounded through a capacitor C1, and the resistor R1 is used for adjusting a current protection threshold.

More specifically, in this embodiment, the ground terminal (i.e., pin No. 1, GND terminal) of the NA555 chip is grounded, the power supply terminal (i.e., pin No. 8, VCC terminal) is connected to the 5V power supply with the filter capacitor C2, the reset terminal (i.e., pin No. 4, R terminal) is connected to the 5V power supply, and the control voltage terminal (i.e., pin No. 5, CVolt terminal) is grounded through the capacitor C8.

The utility model discloses a theory of operation does: when the current signal OIP end receives an overcurrent signal, the output end of the NA555 chip outputs a high level, and the drive signal of the power supply MOS tube is turned off through the optical coupling switch U1, so that the purpose of protecting the power supply is achieved. Meanwhile, after the power control chip releases the fault signal, the drive signal PWMAL is output again by the drive signal PWMAL end output by the power control chip, at this moment, the trigger end of the NA555 receives a high level, and the output end of the NA555 chip outputs a low level, so that the drive of the power MOS tube is recovered to be normal.

The above-mentioned embodiments, further detailed description of the objects, technical solutions and advantages of the present invention, it should be understood that the above-mentioned embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. The utility model provides a take overcurrent protection circuit of self-resuming function which characterized in that: the circuit comprises an NA555 main body circuit and an optical coupling switch circuit; the NA555 main body circuit is used for receiving the current signal OIP and the driving signal PWMAL output by the power control chip and outputting a corresponding level signal from an output end according to the received current signal OIP and the driving signal PWMAL; and the optical coupling switch circuit is connected with the output end of the NA555 main body circuit and used for acquiring a level signal and controlling a driving signal of the power MOS tube according to the level signal.

2. The overcurrent protection circuit with the self-recovery function as claimed in claim 1, wherein: the optical coupling switch circuit comprises an optical coupling switch U1; the model of the optocoupler switch U1 is HCPL-4504.

3. The overcurrent protection circuit with the self-recovery function as claimed in claim 2, wherein: the No. 2 pin of the optocoupler switch U1 is connected with the output end of the NA555 main body circuit, and is grounded through a capacitor C4; the No. 7 pin and the No. 8 pin of the optocoupler switch U1 are connected with a 15V power supply connected with a filter capacitor C3; no. 6 pin of the optical coupling switch U1 is connected with the 15V power supply connected with the filter capacitor C3 through the resistor R3 on one path, is connected with the VN end on the other path, and is connected with the No. 5 pin of the optical coupling switch U1 through the capacitor C6 on one path and is grounded.

4. The overcurrent protection circuit with the self-recovery function as recited in claim 1, 2, or 3, wherein: the NA555 main body circuit comprises an NA555 chip; the trigger end of the NA555 chip is connected with the PWMAL end of the driving signal output by the power control chip through a diode V1 and a capacitor C5 in sequence; the positive end of the diode V1 is connected with a 5V power supply through a resistor R2; the negative terminal of the diode V1 is connected with a 5V power supply through a resistor R4.

5. The overcurrent protection circuit with the self-recovery function as recited in claim 4, wherein: one path of a threshold end of the NA555 chip is connected with a current signal OIP end through a resistor R5, one path of the threshold end is grounded through a capacitor C7, and the other path of the threshold end is connected with a 5V power supply through a resistor R1 and a resistor R1 in sequence; the resistor R1 is also connected with a resistor R14 in parallel; the resistor R1 and the resistor R1 are grounded through a capacitor C1.

6. The overcurrent protection circuit with the self-recovery function as recited in claim 4, wherein: the grounding end of the NA555 chip is grounded, the power supply end is connected with a 5V power supply with a filter capacitor C2, the reset end is connected with the 5V power supply, and the control voltage end is grounded through a capacitor C8.