Anti-reverse-connection and anti-overvoltage slow start combination circuit

Abstract

The utility model relates to the technical field of interactive machine power supply control, in particular to an anti-reverse-connection and anti-overvoltage slow start combination circuit, which comprises an input end, an anti-reverse-connection control circuit, an anti-overvoltage control circuit and a slow start control circuit. The input end is provided with a positive electrode connecting end and a negative electrode connecting end; the anti-reverse connection control circuit comprises a switch tube Q1, and the negative electrode connecting end is connected to a load through the switch tube Q1; a grounding end PGND is connected between the negative electrode connecting end and the switch tube Q1; the anti-overvoltage control circuit comprises a voltage stabilizing diode D4; the slow start control circuit comprises a switch tube Q2, a switch tube Q3, a capacitor C2, a capacitor C4, a resistor R4, a resistor R5, a resistor R7 and a voltage stabilizing diode D1. According to the utility model, load damage caused by artificial mistaken reverse connection of the energy storage battery can be prevented, the problem of load damage caused by power supply fluctuation caused by high load and large current when the mobile equipment is started can be solved, the structure is novel, and the design is ingenious.

Description

TECHNICAL FIELD

[0001] The utility model relates to interactive machine power supply control technical field especially is a kind of anti-reverse connection, overvoltage protection's slow start combination circuit. BACKGROUND

[0002] Now, there are many kinds of switches on the market, but basically all are placed in fixed position indoor, using 220V AC power supply, this power supply mode is not too suitable when used on mobile equipment, at this time, energy storage battery power supply needs to be used.For preventing the case that equipment is damaged when power polarity is reversed artificially during energy storage battery power supply, a small impedance and safe and reliable anti-reverse connection circuit needs to be introduced, and at the same time, when mobile equipment starts, due to large current, energy storage battery output voltage can be extremely unstable, at this time, overvoltage protection and slow start circuit need to be introduced to protect equipment from being damaged by impact current during startup;At present, traditional power supply control circuit is three independent circuits, namely anti-reverse connection circuit, overvoltage protection circuit and slow start circuit, which are independent;But three circuit combinations have redundant and complex structure. SUMMARY

[0003] The utility model provides a kind of anti-reverse connection, overvoltage protection's slow start combination circuit to the problems of prior art, can prevent load damage caused by energy storage battery artificial mis-reverse connection, can prevent load damage caused by power fluctuation due to high load and large current during mobile equipment startup, with novel structure and ingenious design.

[0004] To solve the above technical problems, the utility model adopts the following technical solutions:

[0005] The utility model provides a kind of anti-reverse connection, overvoltage protection's slow start combination circuit, it includes input, anti-reverse connection control circuit, overvoltage protection control circuit and slow start control circuit;

[0006] The input is provided with positive electrode connecting end and negative electrode connecting end;The anti-reverse connection control circuit includes switch tube Q1, and the negative electrode connecting end is connected to load by the switch tube Q1;Ground terminal PGND is connected between the negative electrode connecting end and the switch tube Q1.

[0007] The overvoltage protection control circuit includes voltage stabilizing diode D4.

[0008] The soft-start control circuit includes switching transistors Q2 and Q3, capacitors C2 and C4, resistors R4, R5, and R7, and a Zener diode D1. The positive terminal of the Zener diode D1 is connected to the cathode of the Zener diode D1, the gate of the switching transistor Q1, one end of capacitor C2, the source of the switching transistor Q2, and the emitter of the transistor Q3. The positive terminal of the Zener diode D1, the other end of capacitor C2, and the source of the switching transistor Q1 are grounded. The drain of the switching transistor Q2 is connected to the load. The collector of the transistor Q3 is connected to one end of resistor R7 and one end of resistor R5. The other end of resistor R5 is connected to the gate of the switching transistor Q2, and the other end of resistor R7 is grounded. Capacitor C4 is connected between the base and collector of the transistor Q3. The base of the transistor Q3 is connected to one end of resistor R4, and the other end of resistor R4 is connected to the negative terminal of the Zener diode D4. The anode of the Zener diode D4 is connected to the ground terminal PGND.

[0009] The input terminal also includes inductor L1, inductor L2, resistor R1 and capacitor C1. One end of inductor L1 is connected to one end of resistor R1 and the source of switch Q2. The other end of resistor R1 is connected to one end of capacitor C1 and the other end of capacitor C1 is connected to the drain of switch Q1.

[0010] The soft-start combination circuit further includes a transient voltage suppressor D2, the two ends of which are respectively connected between the positive terminal and the negative terminal.

[0011] The soft-start control circuit further includes a resistor R3, a capacitor C3, and a Zener diode D5. One end of the capacitor C3, one end of the resistor R3, and the cathode of the Zener diode D5 are connected to the positive terminal. The other end of the resistor R3 is connected to the cathode of the Zener diode D4. The other end of the capacitor C3 and the positive terminal of the Zener diode D5 are connected to the gate of the switching transistor Q2.

[0012] The breakdown voltage of the Zener diode D5 is 9.1V.

[0013] The breakdown voltage of the Zener diode D4 is 12V.

[0014] The breakdown voltage of the Zener diode D1 is 9.1V.

[0015] Among them, capacitor C4 is 0.1uF.

[0016] The beneficial effects of this utility model are:

[0017] The utility model discloses can prevent the load damage caused by the artificial mistake reverse connection of energy storage battery, can prevent the load damage caused by power fluctuation when the mobile device starts, solve high load, the structure novel, clever design of big current, novel structure, ingenious design. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a circuit diagram of the slow start combination circuit of anti-reverse connection and anti-overvoltage of the utility model. DETAILED DESCRIPTION

[0019] In order to facilitate the understanding of those skilled in the art, the utility model is further explained below in combination with examples and drawings, and the content mentioned in the embodiment is not the limitation of the utility model. The utility model is described in detail below in combination with drawings.

[0020] An anti-reverse connection and anti-overvoltage slow start combination circuit includes an input end, an anti-reverse connection control circuit, an anti-overvoltage control circuit and a slow start control circuit.

[0021] The input end is provided with a positive connection end and a negative connection end; the anti-reverse connection control circuit includes a switch tube Q1, and the negative connection end is connected to a load through the switch tube Q1; a grounding end PGND is connected between the negative connection end and the switch tube Q1.

[0022] The anti-overvoltage control circuit includes a voltage stabilizing diode D4.

[0023] The slow start control circuit includes a switch tube Q2, a switch tube Q3, a capacitor C2, a capacitor C4, a resistor R4, a resistor R5, a resistor R7 and a voltage stabilizing diode D1, the positive connection end is connected with the cathode of the voltage stabilizing diode D1, the gate of the switch tube Q1, one end of the capacitor C2, the source of the switch tube Q2 and the emitter of the triode Q3, the anode of the voltage stabilizing diode D1, the other end of the capacitor C2 and the source of the switch tube Q1 are grounded respectively, the drain of the switch tube Q2 is connected with a load, the collector of the triode Q3 is connected with one end of the resistor R7 and one end of the resistor R5 respectively, the other end of the resistor R5 is connected with the gate of the switch tube Q2, the other end of the resistor R7 is grounded, the capacitor C4 is connected between the base of the triode Q3 and the collector of the triode Q3, the base of the triode Q3 is connected with one end of the resistor R4, the other end of the resistor R4 is connected with the negative electrode of the voltage stabilizing diode D4, the anode of the voltage stabilizing diode D4 is connected with the grounding end PGND; the breakdown voltage of the voltage stabilizing diode D5 is 9.1V; the breakdown voltage of the voltage stabilizing diode D4 is 12V; the breakdown voltage of the voltage stabilizing diode D1 is 9.1V; the capacitor C4 is 0.1UF.

[0024] In the embodiment of the present application, the slow start control circuit further comprises a resistor R3, a capacitor C3 and a voltage stabilizing diode D5, one end of the capacitor C3, one end of the resistor R3 and the cathode of the voltage stabilizing diode D5 are connected with the positive terminal, the other end of the resistor R3 is connected with the cathode of the voltage stabilizing diode D4, the other end of the capacitor C3 and the anode of the voltage stabilizing diode D5 are connected with the gate of the switch tube Q2. Specifically, under the above setting, the capacitor C3 is a gate-source capacitor, which is used to cooperate with the switch tube Q2 (PMOS) to work and stabilize its state; the resistor R5 is a current-limiting resistor, which is used to protect the switch tube Q2 (PMOS); when VIN> UZ+0.7V, the transistor Q3 is turned on, and the switch tube Q2 (PMOS) is turned off.

[0025] Specifically, when the input power supply 12V is connected to the input terminal with correct polarity, the voltage stabilizing diode D4 is set to 12V, so that the D4 (12V) will not be reversely broken down at the moment of starting, and due to the body diode effect of the switch tube Q2, the current charges the capacitor C4 (0.1UF) through the transistor Q3 (PNP) EB pole, the capacitor C4 and the resistor R7, at this time, the charging current is maximum, the Vce of the transistor Q3 is about 0, that is, the Vgs of the switch tube Q2 (PMOS) is about 0; obviously, the switch tube Q2 (PMOS) cannot be turned on, and the load circuit cannot work; as the charging of the capacitor C4 is completed, the charging current decreases, and the Vgs of the switch tube Q2 is determined by the voltage stabilizing diode D5 (9.1V), at this time, because the input 12V power supply is higher than 9.1V, the voltage stabilizing diode D5 is broken down, Vgs=9.1V, obviously, at this time, the Vgs (gate-source voltage) is greater than the Vgsth (threshold voltage), the switch tube Q2 (PMOS) starts to be turned on, and the current passes through the switch tube Q2 (PMOS) to reach the switch tube Q1 (NMOS) through the load, and due to the body diode effect of the switch tube Q1 (NMOS), the ground loop current is conducted through the body diode of the switch tube Q1 (NMOS).

[0026] At this time, the Vgs (gate-source voltage) of the switch tube Q1 (NMOS) is also greater than the Vgsth (threshold voltage), the switch tube Q1 (NMOS) is turned on, the power supply returns to the ground terminal PGND through the switch tube Q1 (NMOS), and then returns to the negative electrode (negative terminal) of the power supply through the inductor L2 to form a closed loop, the load is normally powered, and the equipment works normally; from the operation of the circuit of the embodiment of the present application, it can be seen that the switch tube Q2 (PMOS) is turned on after the capacitor C4 is charged, and the curvature of the capacitor C4 charging will affect the turn-on time of the switch tube Q2 (PMOS), changing the capacity of the capacitor C4 will affect the charging curvature, so the circuit can achieve the purpose of slow start; the capacitor C3 is a gate-source capacitor, which is used to cooperate with the switch tube Q2 (PMOS) to work and stabilize its state; the resistor R5 is a current-limiting resistor, which is used to protect the switch tube Q2 (PMOS).

[0027] When the input power 12V is connected reversely, the power flows from the ground terminal PGND to the load, at this time, the body diode of the switch tube Q1 (NMOS) is not conductive, and the switch tube Vgs (gate-source voltage) does not meet the requirement, the switch tube Q1 (NMOS) is not conductive, and there is no current loop in the circuit, the load is disconnected and does not work, thereby achieving the purpose of protecting the load; only when the power is normally connected, the 12V power flows through the load, and then the current flows through the source (S) of the switch tube Q1 (NMOS) to the drain (D) of the switch tube Q1 (NMOS) to return to the ground terminal PGND to form a complete loop; it can be seen from the operation of the circuit that when the input power is reversely connected, the circuit cannot work, thereby playing the role of preventing reverse connection.

[0028] Because the Vgs voltage of the switch tube Q1 cannot exceed the maximum rated value of the switch tube Q1 (NMOS), a stabilizing diode D1 (9.1V) needs to be connected to the S pole to stabilize the voltage within the maximum rated value of the switch tube Q1 (NMOS), and a capacitor is connected as a buffer for protecting the MOS tube during starting.

[0029] When the input power 12V is connected reversely, the power flows from the ground terminal PGND to the load, at this time, the body diode of the switch tube Q1 (NMOS) is not conductive, and the switch tube Vgs (gate-source voltage) does not meet the requirement, the switch tube Q1 (NMOS) is not conductive, and there is no current loop in the circuit, the load is disconnected and does not work, thereby achieving the purpose of protecting the load; only when the power is normally connected, the 12V power flows through the load, and then the current flows through the source (S) of the switch tube Q1 (NMOS) to the drain (D) of the switch tube Q1 (NMOS) to return to the ground terminal PGND to form a complete loop; it can be seen from the operation of the circuit that when the input power is reversely connected, the circuit cannot work, thereby playing the role of preventing reverse connection.

[0030] The embodiment of the application can prevent the load damage caused by the artificial mis-reverse connection of the energy storage battery, can prevent the load damage caused by the power fluctuation caused by the high load and large current during the starting of the mobile device, and has novel structure and ingenious design.

[0031] In the embodiment of the application, the input end further comprises an inductor L1, an inductor L2, a resistor R1 and a capacitor C1, one end of the inductor L1 is connected with one end of the resistor R1 and the source of the switch tube Q2, the other end of the resistor R1 is connected with one end of the capacitor C1, and the other end of the capacitor C1 is connected with the drain of the switch tube Q1. Specifically, under the above setting, when the input power 12V is correctly connected by the positive connection end of the input end, it will be filtered by the inductor L1, the resistor R1 and the capacitor C1 first, because the voltage stabilizing value of the voltage stabilizing diode D4 is set to 12V, so the voltage stabilizing diode D4 (12V) will not be reversely broken down at the moment of starting, and because of the body diode effect of the switch tube Q2, the current charges the capacitor C4 (0.1UF) through the triode Q3 (PNP) EB, the capacitor C4 and the resistor R7.

[0032] In the embodiment of the application, the slow start combination circuit further comprises a transient voltage suppressor D2, two ends of the transient voltage suppressor D2 are connected between the positive connection end and the negative connection end respectively. Preferably, the model of the transient voltage suppressor D2 is CP0640SC, which can provide a fast response time to turn on and shunt harmful transient current, thereby protecting the slow start combination circuit of the application.

[0033] The above is only the preferred embodiment of the application, and does not limit the application in any form. Although the application is disclosed as above in the preferred embodiment, it is not intended to limit the application. Any skilled person in the art can make some changes or modifications to the above disclosed technical content without departing from the technical solution of the application, and any simple modification, equivalent change and modification of the above embodiment within the technical solution of the application are all within the scope of the technical solution of the application.

Claims

1. A soft-start combination circuit that protects against reverse connection and overvoltage, characterized in that: The input end, the reverse connection prevention control circuit, the overvoltage prevention control circuit and the slow start control circuit are included. The input end is provided with a positive connection end and a negative connection end; the reverse connection prevention control circuit includes a switch tube Q1, and the negative connection end is connected to a load through the switch tube Q1; a grounding end PGND is connected between the negative connection end and the switch tube Q1. The overvoltage prevention control circuit includes a voltage stabilizing diode D4. The slow start control circuit includes a switch tube Q2, a switch tube Q3, a capacitor C2, a capacitor C4, a resistor R4, a resistor R5, a resistor R7 and a voltage stabilizing diode D1, the positive connection end is connected with a cathode of the voltage stabilizing diode D1, a gate of the switch tube Q1, one end of the capacitor C2, a source of the switch tube Q2 and an emitter of the transistor Q3, the anode of the voltage stabilizing diode D1, the other end of the capacitor C2 and the source of the switch tube Q1 are grounded respectively, the drain of the switch tube Q2 is connected with a load, the collector of the transistor Q3 is connected with one end of the resistor R7 and one end of the resistor R5 respectively, the other end of the resistor R5 is connected with the gate of the switch tube Q2, the other end of the resistor R7 is grounded, the capacitor C4 is connected between the base of the transistor Q3 and the collector of the transistor Q3, the base of the transistor Q3 is connected with one end of the resistor R4, the other end of the resistor R4 is connected with the negative electrode of the voltage stabilizing diode D4, and the anode of the voltage stabilizing diode D4 is connected with the grounding end PGND.

2. A reverse connection and overvoltage protection slow start combination circuit according to claim 1, characterized in that: The input end further includes an inductor L1, an inductor L2, a resistor R1 and a capacitor C1, one end of the inductor L1 is connected with one end of the resistor R1 and the source of the switch tube Q2, the other end of the resistor R1 is connected with one end of the capacitor C1, and the other end of the capacitor C1 is connected with the drain of the switch tube Q1.

3. A reverse connection and overvoltage protection slow start combination circuit according to claim 1, characterized in that: The slow start combination circuit further includes a transient voltage suppressor D2, and the transient voltage suppressor D2 is connected between the positive connection end and the negative connection end.

4. The reverse connection and overvoltage protection slow start combination circuit according to claim 1, characterized in that: The slow start control circuit further includes a resistor R3, a capacitor C3 and a voltage stabilizing diode D5, one end of the capacitor C3, one end of the resistor R3 and the cathode of the voltage stabilizing diode D5 are connected with the positive connection end, the other end of the resistor R3 is connected with the cathode of the voltage stabilizing diode D4, and the other end of the capacitor C3 and the anode of the voltage stabilizing diode D5 are connected with the gate of the switch tube Q2.

5. A reverse connection and overvoltage protection slow start combination circuit according to claim 4, characterized in that: The breakdown voltage of the voltage stabilizing diode D5 is 9.1V.

6. A reverse connection and overvoltage protection slow start combination circuit according to claim 1, characterized in that: The breakdown voltage of the voltage stabilizing diode D4 is 12V.

7. A reverse connection and overvoltage protection slow start combination circuit according to claim 1, characterized in that: The breakdown voltage of the voltage stabilizing diode D1 is 9.1V.

8. A reverse connection and overvoltage protection slow start combination circuit according to claim 1, characterized in that: The capacitor C4 is 0.1UF.

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