Electric power low voltage DC power supply control system

Abstract

The present invention provides an electric low-voltage direct current power supply control system, wherein the overvoltage detection circuit is used to detect the input voltage of the power supply control circuit and output a control signal to the first control circuit when the input voltage is overvoltage; the control output end of the first control circuit is connected to the base of the transistor Q2, and the control input end of the first control circuit is connected to the control output end of the overvoltage detection circuit; the control output end of the second control circuit is connected to the gate of the PMOS tube M1, the first detection input end of the second control circuit is connected to the detection end of the first control circuit, the second detection input end of the second control circuit is connected to the collector of the transistor Q2, the second control circuit controls the conduction and shutdown of the PMOS tube M1 according to the voltage signals of the first detection input end and the second detection input end, and the detection output end con1 and the detection output end con2 of the second control circuit are both connected to the detection input end of the controller; the controller is communicatively connected to the monitoring host through a wireless transmission circuit.

Description

Technical Field

[0001] The present invention relates to a power supply control circuit, and more particularly to a low-voltage DC power supply control system for electricity. Background Art

[0002] When supplying power with low-voltage DC, such as for devices like sensors in a power system, a rectifier circuit is generally used to rectify and filter the commercial power and then supply working DC power to subsequent loads. To ensure the stability of power supply, a switch circuit is needed to turn on and off the power supply path for the electrical appliances. Of course, an overvoltage detection circuit and a switching element are provided in the switch circuit. However, in the prior art, the switch circuit has a single-loop power supply mode. Once the switch circuit is turned off, the subsequent devices cannot be powered. For some application scenarios, such as in power machine rooms and substations where it is necessary to continuously and real-time obtain monitoring data, once the power supply terminal of electrical appliances such as sensors is interrupted, it will cause data interruption.

[0003] Therefore, in order to solve the above technical problems, it is urgent to propose a new technical means. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a low-voltage DC power supply control system for electricity, which uses a dual-channel power supply method to supply power to low-voltage DC electrical appliances. When the main-channel power supply circuit is interrupted, it can automatically switch to the bypass circuit for power supply, and when the main channel resumes, it automatically cuts off the bypass power supply, thus effectively ensuring the continuity of power consumption of low-voltage DC devices.

[0005] A low-voltage DC power supply control system for electricity provided by the present invention includes a controller, a wireless transmission circuit, a P-type triode Q2, a PMOS transistor M1, a diode D1, a first control circuit, an overvoltage detection circuit, and a second control circuit;

[0006] The emitter of the triode Q2 serves as the input end of the power supply control circuit, and the collector of the triode Q2 is connected to the positive pole of the diode D1, and the negative pole of the diode D1 serves as the output end of the power supply control circuit;

[0007] The source of the PMOS transistor M1 is connected to the emitter of the triode Q2, and the drain of the PMOS transistor M1 is connected to the negative pole of the diode D1;

[0008] The overvoltage detection circuit is used to detect the input voltage of the power supply control circuit and output a control signal to the first control circuit when the input voltage is overvoltage;

[0009] The control output end of the first control circuit is connected to the base of the triode Q2, and the control input end of the first control circuit is connected to the control output end of the overvoltage detection circuit;

[0010] The control output terminal of the second control circuit is connected to the gate of PMOS transistor M1. The first detection input terminal of the second control circuit is connected to the detection terminal of the first control circuit. The second detection input terminal of the second control circuit is connected to the collector of triode Q2. The second control circuit controls the on and off of PMOS transistor M1 according to the voltage signals of the first detection input terminal and the second detection input terminal. The detection output terminals con1 and con2 of the second control circuit are both connected to the detection input terminal of the controller. The controller is communicatively connected to the monitoring host through a wireless transmission circuit.

[0011] Further, the first control circuit includes resistor R5, resistor R6, triode Q4, triode Q3, and zener diode ZD4.

[0012] The collector of triode Q3 is connected to the emitter of triode Q2 through resistor R6. The emitter of triode Q3 is grounded. The collector of triode Q3 serves as the control output terminal of the first control circuit and is connected to the base of triode Q2. The base of triode Q3 is connected to the negative electrode of zener diode ZD4. The positive electrode of zener diode ZD4 is grounded. The collector of triode Q4 is connected to the emitter of triode Q2 through resistor R6. The collector of triode Q4 is connected to the base of triode Q3. The emitter of triode Q4 is grounded. The base of triode Q4 serves as the control input terminal of the first control circuit and is connected to the control output terminal of the overvoltage detection circuit.

[0013] Further, the overvoltage detection circuit includes zener diode ZD2, zener diode ZD3, resistor R2, resistor R3, resistor R4, triode Q1, and capacitor C2.

[0014] The negative electrode of zener diode ZD2 is connected to the emitter of triode Q2. The positive electrode of zener diode ZD2 is grounded through resistor R2. The positive electrode of zener diode ZD2 is connected to the base of triode Q1 through resistor R3. The emitter of triode Q1 is grounded through capacitor C2. The collector of triode Q1 is connected to the emitter of triode Q2. The emitter of triode Q1 is connected to one end of resistor R4. The other end of resistor R4 serves as the control output terminal of the overvoltage detection circuit.

[0015] Further, the second control circuit includes zener diode ZD5, resistor R7, resistor R8, resistor R9, resistor R10, resistor R11, resistor R12, resistor R13, resistor R14, resistor R15, resistor R16, triode Q5, triode Q6, triode Q7, triode Q8, triode Q9, triode Q10, diode D2, diode D3, optocoupler G1, optocoupler G2, and capacitor C3.

[0016] The negative electrode of the voltage stabilizing diode ZD5 is connected to the collector of the triode Q2, the positive electrode of the voltage stabilizing diode ZD5 is grounded, one end of the resistor R14 is connected to the negative electrode of the voltage stabilizing diode ZD5 as the second detection input end of the second control circuit, the other end of the resistor R14 is grounded through the capacitor C3, the common connection point between the resistor R14 and the capacitor C4 is connected to the base of the triode Q9, the collector of the triode Q9 is connected to the direct current VCC, the emitter of the triode Q9 is connected to the emitter of the triode Q7, the collector of the triode Q7 is grounded through the resistor R8, the collector of the triode Q8 is connected to the direct current VCC through the resistor R7, the collector of the triode Q8 is connected to the base of the triode Q7, the emitter of the triode Q8 is grounded, the base of the triode Q8 is connected to one end of the resistor R12, the other end of the resistor R12 is connected to the collector of the triode Q4 as the first detection input end of the second control circuit, the collector of the triode Q7 is connected to the base of the triode Q6 through the resistor R13, the emitter of the triode Q6 is grounded, the collector of the triode Q6 is connected to the base of the triode Q5, the emitter of the triode Q5 is grounded, the collector of the triode Q5 is connected to one end of the resistor R11 through the resistor R10, the other end of the resistor R10 is connected to the source of the PMOS transistor M1, the common connection point between the resistor R10 and the resistor R11 is connected to the gate of the PMOS transistor M1 as the control output end of the second control circuit, and the base of the triode Q5 is connected to the source of the PMOS transistor M1 through the resistor R9;

[0017] The base of the triode Q10 is connected to the base of the triode Q8, the emitter of the triode Q10 is connected to the source of the PMOS transistor M1 through the resistor R15, and the collector of the triode Q10 is connected to the common connection point between the resistor R13 and the collector of the triode Q7;

[0018] The positive electrode of the light-emitting diode of the optocoupler G2 is connected to the negative electrode of the voltage stabilizing diode ZD5 through the resistor R16, the negative electrode of the light-emitting diode of the optocoupler G2 is grounded, the collector of the photosensitive triode of the optocoupler G2 is connected to the negative electrode of the diode D3, the positive electrode of the diode D3 is used as the detection output end con1 of the second control circuit, and the emitter of the photosensitive triode of the optocoupler G2 is grounded;

[0019] The positive electrode of the light-emitting diode of the optocoupler G1 is connected to the common connection point between the resistor R12 and the triode Q3, the negative electrode of the light-emitting diode of the optocoupler G1 is grounded, the collector of the photosensitive triode of the optocoupler G1 is connected to the negative electrode of the diode D3, the positive electrode of the diode D3 is used as the detection output end con2 of the second control circuit, and the emitter of the photosensitive triode of the optocoupler G1 is grounded;

[0020] Among them, the triodes Q7 and Q10 are P-type triodes.

[0021] Further, a power supply circuit is further included, and the power supply module outputs direct current VCC;

[0022] The power supply circuit includes a resistor R1, a voltage regulator diode ZD1, and a capacitor C1;

[0023] One end of the resistor R1 is connected to the emitter of the triode Q2, the other end of the resistor R1 is connected to the negative electrode of the voltage regulator diode ZD1, the positive electrode of the voltage regulator diode ZD1 is grounded, the negative electrode of the voltage regulator diode ZD1 is grounded through the capacitor C1, and the common connection point between the negative electrode of the voltage regulator diode ZD1 and the capacitor C1 serves as the output end of the power supply circuit to output direct current VCC.

[0024] Furthermore, the controller is a single-chip microcomputer.

[0025] Furthermore, the wireless transmission circuit is a 4G or 5G communication module.

[0026] Advantages of the present invention: Through the present invention, when supplying power to low-voltage DC electrical devices, a dual-channel power supply method is adopted for power supply. When the main channel power supply circuit is interrupted, it can automatically switch to the bypass circuit for power supply, and when the main channel resumes, it automatically cuts off the bypass power supply, thereby effectively ensuring the power supply continuity of low-voltage DC devices, and can also upload the switching information in real time, which is conducive to taking timely maintenance and inspection measures. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The following describes the present invention in further detail with reference to the drawings and embodiments:

[0028] Figure 1 is a structural schematic diagram of the present invention.

[0029] Figure 2 is a circuit schematic diagram of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] The following further elaborates on the present invention in detail with reference to the accompanying drawings of the specification:

[0031] A low-voltage DC power supply control system provided by the present invention includes a controller, a wireless transmission circuit, a P-type triode Q2, a PMOS transistor M1, a diode D1, a first control circuit, an overvoltage detection circuit, and a second control circuit;

[0032] The emitter of the triode Q2 serves as the input end of the power supply control circuit, and the collector of the triode Q2 is connected to the positive electrode of the diode D1, and the negative electrode of the diode D1 serves as the output end of the power supply control circuit;

[0033] The source of the PMOS transistor M1 is connected to the emitter of the triode Q2, and the drain of the PMOS transistor M1 is connected to the negative electrode of the diode D1;

[0034] The overvoltage detection circuit is used to detect the input voltage of the power supply control circuit and output a control signal to the first control circuit when the input voltage is overvoltage;

[0035] The control output end of the first control circuit is connected to the base of the triode Q2, and the control input end of the first control circuit is connected to the control output end of the overvoltage detection circuit;

[0036] The control output end of the second control circuit is connected to the gate of the PMOS transistor M1. The first detection input end of the second control circuit is connected to the detection end of the first control circuit. The second detection input end of the second control circuit is connected to the collector of the triode Q2. The second control circuit controls the on and off of the PMOS transistor M1 according to the voltage signals at the first detection input end and the second detection input end. The detection output ends con1 and con2 of the second control circuit are both connected to the detection input end of the controller; The controller is communicatively connected to the monitoring host through a wireless transmission circuit. With the above structure, a dual-channel power supply method is adopted to supply power to low-voltage DC electrical devices. When the main-channel power supply circuit is interrupted, it can automatically switch to the bypass circuit for power supply, and automatically cut off the bypass power supply when the main channel resumes, thus effectively ensuring the power continuity of low-voltage DC devices, and can upload the switching information in real time, which is conducive to timely making maintenance and inspection measures.

[0037] Among them, the wireless transmission circuit uses existing 4G or 5G communication modules, and the controller uses existing single-chip microcomputers, such as: 89C51 series single-chip microcomputers, STM32 series single-chip microcomputers.

[0038] In this embodiment, the first control circuit includes a resistor R5, a resistor R6, a triode Q4, a triode Q3, and a zener diode ZD4;

[0039] The collector of the triode Q3 is connected to the emitter of the triode Q2 through the resistor R6. The emitter of the triode Q3 is grounded. The collector of the triode Q3 is used as the control output end of the first control circuit and is connected to the base of the triode Q2. The base of the triode Q3 is connected to the negative pole of the zener diode ZD4. The positive pole of the zener diode ZD4 is grounded. The collector of the triode Q4 is connected to the emitter of the triode Q2 through the resistor R6. The collector of the triode Q4 is connected to the base of the triode Q3. The emitter of the triode Q4 is grounded. The base of the triode Q4 is used as the control input end of the first control circuit and is connected to the control output end of the overvoltage detection circuit; With the above structure, the on and off of the triode Q4 controls the off and on of the triode Q3, thereby ensuring the stability of the off and on of the triode Q2.

[0040] In this embodiment, the overvoltage detection circuit includes a zener diode ZD2, a zener diode ZD3, a resistor R2, a resistor R3, a resistor R4, a triode Q1, and a capacitor C2;

[0041] The negative electrode of the voltage stabilizing diode ZD2 is connected to the emitter of the triode Q2. The positive electrode of the voltage stabilizing diode ZD2 is grounded through the resistor R2, and the positive electrode of the voltage stabilizing diode ZD2 is connected to the base of the triode Q1 through the resistor R3. The emitter of the triode Q1 is grounded through the capacitor C2. The collector of the triode Q1 is connected to the emitter of the triode Q2. One end of the emitter of the triode Q1 is connected to one end of the resistor R4, and the other end of the resistor R4 serves as the control output end of the overvoltage detection circuit.

[0042] Under the above structure, when the input voltage is normal, the triode Q1 is cut off, the triode Q4 is cut off, the conduction voltage is provided to the triode Q3 through the resistor R5, the triode Q3 is saturated and conducting, and the emitter and base of the triode Q2 are reverse-biased and conducting, so as to supply power to the load RL.

[0043] When there is overvoltage, the voltage stabilizing diode ZD2 conducts, so that the triode Q1 conducts. Due to the existence of the capacitor C2, the triode Q4 will not conduct immediately. The capacitor C2 is charged. If the voltage at this time is an interfering spike voltage, which is not enough to make the triode Q4 conduct, then the protection will not be immediately executed and the power will not be cut off. Moreover, if there is no subsequent spike voltage to make ZD2 conduct, then the triode Q2 will not be cut off, thus ensuring the stable and continuous power supply. If the overvoltage causes the triode Q1 to conduct continuously, then the voltage of the capacitor C2 will rise continuously, so that the triode Q4 conducts, the triode Q3 is cut off, and then the triode Q2 is cut off, stopping the power supply to the load. When the voltage stabilizing diode ZD2 returns to cut-off, the capacitor C2 still discharges through the resistor R4 and the loop between the base and emitter of the triode Q4, so that the triode Q4 conducts for a certain period of time, thus playing a role of delayed protection. When the voltage stabilizing diode ZD2 returns to cut-off and the voltage of the capacitor C2 is not enough to maintain the conduction of the triode Q4, the triode Q2 resumes conduction and then supplies power. Therefore, based on the above structure, the whole circuit can be prevented from being locked and unable to recover automatically.

[0044] In this embodiment, the second control circuit includes a voltage stabilizing diode ZD5, resistors R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, triodes Q5, Q6, Q7, Q8, Q9, Q10, diodes D2, D3, optocouplers G1, G2 and a capacitor C3;

[0045] The negative electrode of the voltage stabilizing diode ZD5 is connected to the collector of the triode Q2, the positive electrode of the voltage stabilizing diode ZD5 is grounded, one end of the resistor R14 is connected to the negative electrode of the voltage stabilizing diode ZD5 as the second detection input end of the second control circuit, the other end of the resistor R14 is grounded through the capacitor C3, the common connection point between the resistor R14 and the capacitor C4 is connected to the base of the triode Q9, the collector of the triode Q9 is connected to the DC power supply VCC, the emitter of the triode Q9 is connected to the emitter of the triode Q7, the collector of the triode Q7 is grounded through the resistor R8, the collector of the triode Q8 is connected to the DC power supply VCC through the resistor R7, the collector of the triode Q8 is connected to the base of the triode Q7, the emitter of the triode Q8 is grounded, the base of the triode Q8 is connected to one end of the resistor R12, the other end of the resistor R12 is connected to the collector of the triode Q4 as the first detection input end of the second control circuit, the collector of the triode Q7 is connected to the base of the triode Q6 through the resistor R13, the emitter of the triode Q6 is grounded, the collector of the triode Q6 is connected to the base of the triode Q5, the emitter of the triode Q5 is grounded, the collector of the triode Q5 is connected to one end of the resistor R11 through the resistor R10, the other end of the resistor R10 is connected to the source of the PMOS transistor M1, the common connection point between the resistor R10 and the resistor R11 is connected to the gate of the PMOS transistor M1 as the control output end of the second control circuit, and the base of the triode Q5 is connected to the source of the PMOS transistor M1 through the resistor R9;

[0046] The base of the triode Q10 is connected to the base of the triode Q8, the emitter of the triode Q10 is connected to the source of the PMOS transistor M1 through the resistor R15, and the collector of the triode Q10 is connected to the common connection point between the resistor R13 and the collector of the triode Q7;

[0047] The positive electrode of the light emitting diode of the optocoupler G2 is connected to the negative electrode of the voltage stabilizing diode ZD5 through the resistor R16, the negative electrode of the light emitting diode of the optocoupler G2 is grounded, the collector of the photosensitive triode of the optocoupler G2 is connected to the negative electrode of the diode D3, the positive electrode of the diode D3 is used as the detection output end con1 of the second control circuit, and the emitter of the photosensitive triode of the optocoupler G2 is grounded;

[0048] The positive electrode of the light emitting diode of the optocoupler G1 is connected to the common connection point between the resistor R12 and the triode Q3, the negative electrode of the light emitting diode of the optocoupler G1 is grounded, the collector of the photosensitive triode of the optocoupler G1 is connected to the negative electrode of the diode D3, the positive electrode of the diode D3 is used as the detection output end con2 of the second control circuit, and the emitter of the photosensitive triode of the optocoupler G1 is grounded;

[0049] Among them, the triodes Q7 and Q10 are P-type triodes.

[0050] Resistor R14 is used to detect whether transistor Q2 has an output, and resistor R12 is used to detect whether the overvoltage detection circuit is in overvoltage protection execution. When transistor Q2 has an output and the overvoltage detection circuit does not output an overvoltage control signal, transistor Q9 is turned on, and transistor Q8 is turned on. At this time, transistor Q7 is turned on, and then transistor Q6 is controlled to be turned on. Transistor Q6 is turned on to lower the base potential of transistor Q5, and transistor Q5 is turned off. At this time, PMOS tube M1 is turned off, and the bypass provided by PMOS tube M1 does not supply power. At this time, optocoupler G2 is in the on state, and the terminal connected to the controller and diode D3 is in a low level state. In addition, optocoupler G1 is also in the on state, and the terminal connected to the controller and diode D2 is in a low level state. The controller determines that the power supply is normal based on the low level state of these two terminals.

[0051] When transistor Q2 has no output, there are two situations: one is the overvoltage protection state, and the other is the fault of transistor Q2 and its control circuit.

[0052] If in overvoltage protection:

[0053] At this time, transistor Q4 is turned on, and the collector of transistor Q4 is at a low level. At this time, transistor Q8 is turned off. Due to the overvoltage protection, transistor Q2 is also turned off and has no output. Although transistor Q7 is turned on at this time, transistor Q9 is still turned off. Since the base of transistor Q10 is set to a low level, transistor Q10 is turned on. At this time, transistor Q6 is still turned on, and PMOS tube M1 is in the off state. Although the overvoltage protection causes a temporary power interruption, it protects subsequent electrical devices. At this time, the terminal connected to the controller and the diode D3 and the terminal connected to the controller and the diode D2 are both set to a high level state. The controller recognizes it as an overvoltage protection state and uploads the overvoltage protection information in real time.

[0054] If the transistor Q2 has no output and is not in the overvoltage state, then it is the second case. At this time, the transistor Q8 is still in the on state, and the transistor Q10 is in the off state; the transistor Q9 is in the off state, and the transistor Q6 is cut off, so the transistor Q5 is turned on, the PMOS tube M1 is turned on, and the bypass provided by the PMOS tube M1 is powered, completing the automatic switching. At this time, the terminal connected to the controller and the diode D2 is set to a low level, and the terminal connected to the controller and the diode D3 is set to a high level. The controller determines that the current main power supply circuit is faulty and uploads the alarm information in real time.

[0055] When transistor Q2 resumes power supply, transistor Q9 resumes conduction, at which point transistor Q6 resumes conduction, transistor Q5 turns off, and PMOS tube M1 turns off accordingly, thus restoring power supply to the main channel of transistor Q2.

[0056] In this embodiment, a power supply circuit is further included, and the power supply module outputs direct current VCC;

[0057] The power supply circuit includes a resistor R1, a voltage stabilizing diode ZD1, and a capacitor C1;

[0058] One end of the resistor R1 is connected to the emitter of the triode Q2, the other end of the resistor R1 is connected to the negative electrode of the voltage stabilizing diode ZD1, the positive electrode of the voltage stabilizing diode ZD1 is grounded, the negative electrode of the voltage stabilizing diode ZD1 is grounded through the capacitor C1, and the common connection point between the negative electrode of the voltage stabilizing diode ZD1 and the capacitor C1 is used as the output end of the power supply circuit to output direct current VCC. Through the above structure, stable direct current VCC can be provided; for the power supply of the controller, an independent power supply method is adopted, such as battery power supply, an on-line power supply loop composed of an independent rectification, filtering, and voltage stabilizing circuit, or a redundant power supply system composed of a battery and an on-line power supply loop.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A low voltage DC power supply control system, characterized in that: It includes a controller, a wireless transmission circuit, a P-type transistor Q2, a PMOS tube M1, a diode D1, a first control circuit, an overvoltage detection circuit and a second control circuit; The emitter of the transistor Q2 serves as the input end of the power supply control circuit, the collector of the transistor Q2 is connected to the anode of the diode D1, and the cathode of the diode D1 serves as the output end of the power supply control circuit; The source of the PMOS tube M1 is connected to the emitter of the transistor Q2, and the drain of the PMOS tube M1 is connected to the cathode of the diode D1; The overvoltage detection circuit is used to detect the input voltage of the power supply control circuit and output a control signal to the first control circuit when the input voltage is overvoltage; The control output terminal of the first control circuit is connected to the base of the transistor Q2, and the control input terminal of the first control circuit is connected to the control output terminal of the overvoltage detection circuit; The control output end of the second control circuit is connected to the gate of the PMOS tube M1, the first detection input end of the second control circuit is connected to the detection end of the first control circuit, the second detection input end of the second control circuit is connected to the collector of the transistor Q2, the second control circuit controls the on and off of the PMOS tube M1 according to the voltage signal of the first detection input end and the second detection input end, the detection output end con1 and the detection output end con2 of the second control circuit are both connected to the detection input end of the controller; the controller is connected to the monitoring host through a wireless transmission circuit; The first control circuit includes a resistor R5, a resistor R6, a transistor Q4, a transistor Q3 and a voltage regulator ZD4; The collector of the transistor Q3 is connected to the emitter of the transistor Q2 through the resistor R6, the emitter of the transistor Q3 is grounded, the collector of the transistor Q3 is connected to the base of the transistor Q2 as the control output end of the first control circuit, the base of the transistor Q3 is connected to the negative electrode of the voltage-stabilizing tube ZD4, the positive electrode of the voltage-stabilizing tube ZD4 is grounded, the collector of the transistor Q4 is connected to the emitter of the transistor Q2 through the resistor R6, the collector of the transistor Q4 is connected to the base of the transistor Q3, the emitter of the transistor Q4 is grounded, and the base of the transistor Q4 is connected to the control output end of the overvoltage detection circuit as the control input end of the first control circuit; The overvoltage detection circuit includes a voltage regulator tube ZD2, a voltage regulator tube ZD3, a resistor R2, a resistor R3, a resistor R4, a transistor Q1 and a capacitor C2; The cathode of the voltage regulator tube ZD2 is connected to the emitter of the transistor Q2, the anode of the voltage regulator tube ZD2 is grounded through the resistor R2, the anode of the voltage regulator tube ZD2 is connected to the base of the transistor Q1 through the resistor R3, the emitter of the transistor Q1 is grounded through the capacitor C2, the collector of the transistor Q1 is connected to the emitter of the transistor Q2, the emitter of the transistor Q1 is connected to one end of the resistor R4, and the other end of the resistor R4 serves as the control output end of the overvoltage detection circuit; The second control circuit includes a voltage regulator ZD5, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a transistor Q5, a transistor Q6, a transistor Q7, a transistor Q8, a transistor Q9, a transistor Q10, a diode D2, a diode D3, an optical coupler G1, an optical coupler G2 and a capacitor C3; The cathode of the voltage regulator tube ZD5 is connected to the collector of the transistor Q2, the anode of the voltage regulator tube ZD5 is grounded, one end of the resistor R14 is connected to the cathode of the voltage regulator tube ZD5 as the second detection input end of the second control circuit, the other end of the resistor R14 is grounded through the capacitor C3, the common connection point between the resistor R14 and the capacitor C4 is connected to the base of the transistor Q9, the collector of the transistor Q9 is connected to the direct current VCC, the emitter of the transistor Q9 is connected to the emitter of the transistor Q7, the collector of the transistor Q7 is grounded through the resistor R8, the collector of the transistor Q8 is connected to the direct current VCC through the resistor R7, the collector of the transistor Q8 is connected to the base of the transistor Q7, the emitter of the transistor Q8 is grounded, the base of the transistor Q8 is connected to the DC power VCC, and the collector of the transistor Q8 is connected to the base of the transistor Q7. One end of the resistor R12 is connected, the other end of the resistor R12 is connected to the collector of the transistor Q4 as the first detection input end of the second control circuit, the collector of the transistor Q7 is connected to the base of the transistor Q6 through the resistor R13, the emitter of the transistor Q6 is grounded, the collector of the transistor Q6 is connected to the base of the transistor Q5, the emitter of the transistor Q5 is grounded, the collector of the transistor Q5 is connected to one end of the resistor R10 through the resistor R11, the other end of the resistor R10 is connected to the source of the PMOS tube M1, the common connection point of the resistor R10 and the resistor R11 is connected to the gate of the PMOS tube M1 as the control output end of the second control circuit, and the base of the transistor Q5 is connected to the source of the PMOS tube M1 through the resistor R9; The base of the transistor Q10 is connected to the base of the transistor Q8, the emitter of the transistor Q10 is connected to the source of the PMOS tube M1 through the resistor R15, and the collector of the transistor Q10 is connected to the common connection point between the resistor R13 and the collector of the transistor Q7; The positive electrode of the light emitting diode of the optocoupler G2 is connected to the negative electrode of the voltage regulator tube ZD5 through the resistor R16, the negative electrode of the light emitting diode of the optocoupler G2 is grounded, the collector of the phototransistor of the optocoupler G2 is connected to the negative electrode of the diode D3, the positive electrode of the diode D3 serves as the detection output terminal con1 of the second control circuit, and the emitter of the phototransistor of the optocoupler G2 is grounded; The positive electrode of the light emitting diode of the optocoupler G1 is connected to the common connection point between the resistor R12 and the transistor Q8, the negative electrode of the light emitting diode of the optocoupler G1 is grounded, the collector of the phototransistor of the optocoupler G1 is connected to the negative electrode of the diode D3, the positive electrode of the diode D3 serves as the detection output terminal con2 of the second control circuit, and the emitter of the phototransistor of the optocoupler G1 is grounded; Among them, transistor Q7 and transistor Q10 are P-type transistors.

2. According to claim 1, the low voltage DC power supply control system is characterized in that: Also includes a power supply circuit, the power supply circuit outputs a direct current VCC; The power supply circuit includes a resistor R1, a voltage regulator ZD1 and a capacitor C1; One end of the resistor R1 is connected to the emitter of the transistor Q2, and the other end of the resistor R1 is connected to the cathode of the voltage regulator ZD1. The anode of the voltage regulator ZD1 is grounded, and the cathode of the voltage regulator ZD1 is grounded through the capacitor C1. The common connection point between the cathode of the voltage regulator ZD1 and the capacitor C1 serves as the output end of the power supply circuit to output direct current VCC.

3. The low voltage DC power supply control system according to claim 1, characterized in that: The controller is a single chip microcomputer.

4. The low voltage DC power supply control system according to claim 1, characterized in that: The wireless transmission circuit is a 4G or 5G communication module.

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