Positive and negative direct current double-voltage input reverse connection prevention protection control circuit

Abstract

The utility model provides a positive and negative direct current double voltage input reverse connection prevention protection control circuit, which comprises a polarity judgment module, a voltage judgment module, a switch driving module and a load switch control module, and is characterized in that the polarity judgment module comprises diodes V1, V4 and V9; all forms of power supply polarity access of the point A, the point B and the point C are determined through unilateral conductivity of diodes V1, V4 and V9; the voltage judgment module comprises a resistor R6, a resistor R12 and a voltage reference power supply V8; by adjusting the resistance values of a resistor R6 and a resistor R12 which are connected in series, the reference voltage of a voltage reference power supply V8 reaches a stabilized voltage when the voltage of a point A and the voltage of a point C meet the condition of | VCC-| < VAC < = (VCC + | VCC-|), and the uniqueness of power supply polarity access of the point A, the point B and the point C can be determined by combining a polarity judgment module; the switch driving module is used for controlling a switch device in the load switch control module; the load switch control module is used for controlling on or off of load power supply. And an anti-reverse connection protection function is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply and electromechanical control, in particular to a positive and negative direct current dual voltage input anti-reverse connection protection control circuit. Background Art

[0002] In the field of power supply and electromechanical control technology, input reverse polarity protection is one of the important measures to ensure the safe operation of equipment and prevent circuit damage.

[0003] For many existing applications, a single power supply is sufficient to meet the needs, so adopting a single power supply system can reduce system cost and complexity. At the same time, under a single power supply system, the circuit design is relatively simple, easy to implement and maintain. In addition, under a single power supply system, since there is only one power input, the control logic of the anti-reverse polarity protection is more direct and reliable.

[0004] Traditional anti-reverse polarity protection control circuits are mainly designed for single power supply systems, and anti-reverse polarity protection for single power supply is achieved by connecting components such as diodes in series.

[0005] However, when positive and negative power supplies are input at the same time, this protection circuit based on a single power supply system cannot effectively determine the input of the positive power supply and the reference power supply, and thus cannot achieve anti-reverse connection protection for the positive and negative DC power supplies.

[0006] Therefore, with the diversification of power supply types and the improvement of performance requirements for electrical equipment, power supply and electromechanical control systems have put forward higher requirements for input reverse polarity protection control circuits.

[0007] Currently, in the case of dual voltage input, there are still the following two technical difficulties:

[0008] On the one hand, the system needs to be able to accurately identify which is the positive power supply, which is the negative power supply, or which is the reference power supply;

[0009] On the other hand, dual voltage inputs mean there are many possible connection combinations, and the control logic must be able to handle these combinations to ensure correct protection against reverse connection in all cases. Utility Model Content

[0010] The technical problem to be solved by the utility model is how to design an anti-reverse connection protection control circuit suitable for positive and negative DC dual voltage input states.

[0011] In order to solve the above technical problems, the utility model provides a positive and negative DC dual voltage input anti-reverse connection protection control circuit, the circuit has a positive voltage VCC, a reference voltage GND and a negative voltage VCC-, and in the normal input form of the circuit, the point where the positive voltage VCC is connected is point A, the point where the reference voltage GND is connected is point B, and the point where the negative voltage VCC- is connected is point C. The circuit also includes a polarity judgment module, a voltage judgment module, a switch drive module and a load switch control module, wherein:

[0012] The polarity determination module includes a diode V1, a diode V4, and a diode V9; the polarity determination module determines all forms of power polarity access at points A, B, and C through the unidirectional conductivity of the diodes V1, V4, and V9;

[0013] The voltage judgment module includes a resistor R6, a resistor R12, and a voltage reference power supply V8. The voltage judgment module adjusts the resistance values ​​of the resistors R6 and R12 connected in series so that when the voltages at points A and C meet the condition |VCC-|<VAC≤(VCC+|VCC-|), the reference voltage of the voltage reference power supply V8 reaches a regulated voltage. In combination with the polarity judgment module, the uniqueness of the power polarity access at points A, B, and C can be determined.

[0014] The switch driving module is used to control the switch device in the load switch control module;

[0015] The load switch control module is used to control the on or off of the load power supply.

[0016] Furthermore, the load switch control module includes an electronic control device K1 and an electronic control device K2; wherein:

[0017] The anode of the diode V1 is connected to the positive voltage VCC, and the cathode of the diode V1 is connected to the electronic control device K1. The diode V1 allows the point A to only be connected to the positive voltage VCC or the reference voltage GND.

[0018] The anode of the diode V4 is connected to the reference voltage GND, and the cathode of the diode V4 is connected to the electronic control device K2. The diode V4 allows the point B to only be connected to the positive voltage VCC or the reference voltage GND.

[0019] The anode of the diode V9 is connected to pin 3 of the voltage reference power supply V8, and the cathode of the diode V9 is connected to the negative voltage VCC-. Through the diode V9, point C can only be connected to the reference voltage GND or the negative voltage VCC-.

[0020] Furthermore, the load switch control module further includes a switch tube Q1, a switch tube Q2, a freewheeling diode V2 and a freewheeling diode V5; wherein the freewheeling diode V2 is connected in parallel with the electronic control device K1; and the freewheeling diode V5 is connected in parallel with the electronic control device K2.

[0021] Furthermore, the switch driving module includes an optocoupler E1, an optocoupler E2 and a voltage regulator diode V7, wherein:

[0022] Pin 1 of the optocoupler E1 is connected to the cathode of the diode V1, pin 2 of the optocoupler E1 is connected to pin 1 of the optocoupler E2, pin 3 of the optocoupler E1 is connected to the base of the switch tube Q1, and pin 4 of the optocoupler E1 is connected to the cathode of the diode V1;

[0023] Pin 2 of the optocoupler E2 is connected to pin 1 of the voltage reference power supply V8, pin 3 of the optocoupler E2 is connected to the base of the switch tube Q2, and pin 4 of the optocoupler E2 is connected to the cathode of the diode V4;

[0024] The anode of the voltage stabilizing diode V7 is grounded, and the cathode of the voltage stabilizing diode V7 is connected to the positive voltage VCC through the diode V1 .

[0025] Furthermore, the switch driving module further includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a capacitor C1, a capacitor C3, a Zener diode V3, and a Zener diode V6; wherein,

[0026] The resistor R1 and the resistor R3 are connected in series between the cathode of the diode V1 and pin 1 of the optocoupler E1;

[0027] The resistor R2 and the resistor R4 are connected in series and then in parallel with the voltage stabilizing diode V3. The cathode of the voltage stabilizing diode V3 is connected to the 4th pin of the optocoupler E1.

[0028] The resistor R5 is connected to the base of the switch tube Q1;

[0029] The resistor R7 is connected in parallel with the capacitor C1 and then connected to the base of the switch tube Q1;

[0030] The resistor R8 and the resistor R9 are connected in series and then connected in parallel with the voltage stabilizing diode V6. The cathode of the voltage stabilizing diode V6 is connected to the 4th pin of the optocoupler E2.

[0031] The resistor R10 is connected to the base of the switch tube Q2;

[0032] The resistor R11 and the capacitor C3 are connected in parallel and then connected to the base of the switch tube Q2.

[0033] Further, the voltage judging module further comprises a capacitor C2 and a capacitor C4; wherein:

[0034] The resistor R6 and the resistor R12 are connected in series and then connected in parallel with the capacitor C2, and are connected to the negative electrode of the diode V1 and the positive electrode of the diode V9; the capacitor C2 is used for filtering high-frequency interference of power input;

[0035] The resistor R12 and the capacitor C4 are connected in parallel and then connected to the 2 pin of the voltage reference power supply V8; the capacitor C4 is used for filtering interference at the reference voltage of the voltage reference power supply V8.

[0036] Further, the voltage reference power supply V8 is a precision shunt voltage regulator.

[0037] Further, the switch tube Q1 and the switch tube Q2 can adopt a triode or a MOS tube or an IGBT, and are used for controlling the on-off of the electric control device K1 and the electric control device K2.

[0038] Further, the electric control device K1 and the electric control device K2 can adopt a relay or a contactor, and are used for controlling the conduction or the turn-off of load power supply.

[0039] Compared with the prior art, the utility model has the advantages of the following:

[0040] The utility model discloses a polarity judging module, a voltage judging module, a switch driving module and a load switch control module are used to realize the functions of cutting off the load power supply when the power input is wrong under the condition of positive and negative direct current double voltage input, realizing the anti-reverse connection protection function; at the same time, the current limiting, under voltage and over voltage protection functions are complete, the anti-interference ability is strong, and the application under a variety of voltage system and strong electromagnetic interference environment can be satisfied. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 It is the principle block diagram of the utility model;

[0042] Figure 2 It is the circuit diagram of the utility model. DETAILED DESCRIPTION

[0043] In order to make the technical scheme and technical effect of the utility model more clear, the technical scheme in the utility model embodiment will be described clearly and completely in combination with the drawings in the embodiment, and obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments.

[0044] This utility model aims to provide a positive and negative DC dual voltage input reverse connection protection control circuit. Under the conditions of positive and negative DC dual voltage input, the circuit can cut off the load power supply when the power input is connected incorrectly. It also has current limiting, undervoltage, and overvoltage protection functions. It can meet the application requirements of various voltage systems and strong electromagnetic interference environments.

[0045] refer to Figure 1 The circuit mainly includes a polarity judgment module, a voltage judgment module, a switch driver module, and a load switch control module. The output of the power input module is connected to the input of the polarity judgment module, the output of the polarity judgment module is connected to the input of the voltage judgment module, the output of the voltage judgment module is connected to the input of the switch driver module, the output of the switch driver module is connected to the input of the load switch control module, and the output of the load switch control module is connected to load 1 and load 2.

[0046] refer to Figure 2 The circuit has a positive voltage VCC, a reference voltage GND and a negative voltage VCC-. In the normal input form of the circuit, the point where the positive voltage VCC is connected is point A, the point where the reference voltage GND is connected is point B, and the point where the negative voltage VCC- is connected is point C.

[0047] The normal input form of positive and negative DC dual voltage is:

[0048] The positive voltage VCC is connected to point A, the reference voltage GND is connected to point B, and the negative voltage VCC- is connected to point C.

[0049] Abnormal wiring form of positive and negative DC dual voltage is:

[0050] Type 1: The positive voltage VCC is connected to point A, the negative voltage VCC-VCC- is connected to point B, and the reference voltage GND is connected to point C;

[0051] Type 2: The reference voltage GND is connected to point A, the positive voltage VCC is connected to point B, and the negative voltage VCC- is connected to point C;

[0052] Type 3: The reference voltage GND is connected to point A, the negative voltage VCC- is connected to point B, and the positive voltage VCC is connected to point C;

[0053] Type 4: Negative voltage VCC- is connected to point A, positive voltage VCC is connected to point B, and reference voltage GND is connected to point C;

[0054] Type 5: Negative voltage VCC- is connected to point A, reference voltage GND is connected to point B, and positive voltage VCC is connected to point C.

[0055] Therefore, in the case of dual voltage input, the system needs to be able to accurately identify which is the positive power supply, which is the negative power supply, and which is the reference power supply; and be able to handle these different combinations to ensure that correct anti-reverse polarity protection is provided in any situation.

[0056] The following combination Figure 2 , the polarity judgment module, voltage judgment module, switch driving module and load switch control module are further described in detail.

[0057] 1. Electronic components of each module:

[0058] The polarity determination module includes a diode V1, a diode V4 and a diode V9.

[0059] The voltage determination module includes a resistor R6, a resistor R12, a capacitor C2, a capacitor C4 and a voltage reference power supply V8.

[0060] The switch driving module includes resistor R1, resistor R2, resistor R3, resistor R4, resistor R5, resistor R7, resistor R8, resistor R9, resistor R10, resistor R11, capacitor C1, capacitor C3, Zener diode V3, Zener diode V6, Zener diode V7, optocoupler E1 and optocoupler E2.

[0061] The load switch control module includes a switch tube Q1, a switch tube Q2, an electronic control device K1, an electronic control device K2, a freewheeling diode V2 and a freewheeling diode V5.

[0062] Preferably, the voltage reference power supply V8 uses a precision shunt regulator. When the reference voltage of the voltage reference power supply V8 (the voltage of pin 2 to pin 3) reaches the regulated voltage, the cathode (pin 1) to the anode (pin 3) of the voltage reference power supply V8 is turned on.

[0063] Optionally, the switch tubes Q1 and Q2 may be triodes, MOS tubes, or IGBTs, which are used to control the on and off of the electronic control devices K1 and K2.

[0064] Optionally, the electronic control devices K1 and K2 may be relays or contactors for controlling the on or off of the power supply to the load.

[0065] 2. Functional description of each module:

[0066] 2.1 Polarity Judgment Module

[0067] The polarity judgment module determines all forms of power polarity access at points A, B, and C by utilizing the unidirectional conductivity of diodes V1, V4, and V9.

[0068] Further explanation:

[0069] The anode of the diode V1 is connected to the positive voltage VCC, and the cathode of the diode V1 is connected to the electronic control device K1. Through the diode V1, point A can only be connected to the positive voltage VCC or the reference voltage GND.

[0070] The anode of the diode V4 is connected to the reference voltage GND, and the cathode of the diode V4 is connected to the electronic control device K2. The diode V4 allows point B to only be connected to the positive voltage VCC or the reference voltage GND.

[0071] The anode of diode V9 is connected to pin 3 of voltage reference power supply V8, and the cathode of diode V9 is connected to negative voltage VCC-. Through diode V9, point C can only be connected to reference voltage GND or negative voltage VCC-.

[0072] 2.2 Voltage judgment module

[0073] The voltage judgment module can set the circuit startup voltage Von by adjusting the resistance values ​​of resistors R6 and R12, and simultaneously realize the undervoltage protection function.

[0074] The voltage judgment module adjusts the resistance values ​​of the resistors R6 and R12 connected in series so that when the voltages at points A and C meet the condition of |VCC-|<VAC≤(VCC+|VCC-|), the reference voltage of the voltage reference power supply V8 (the voltage between pins 2 and 3) reaches the regulated voltage. Combined with the polarity judgment module, it can be determined that point A can only be connected to the positive voltage VCC and point C can only be connected to the negative voltage VCC-, thereby achieving the uniqueness of the power polarity access at points A, B, and C.

[0075] Going further:

[0076] Resistor R6 and resistor R12 are connected in series and then in parallel with capacitor C2, and connected to the cathode of diode V1 and the anode of diode V9. Capacitor C2 is used to filter out high-frequency interference from the power input.

[0077] Resistor R12 and capacitor C4 are connected in parallel to pin 2 of the voltage reference power supply V8. Capacitor C4 is used to filter out interference at the reference voltage of the precision shunt regulator to avoid malfunction and ensure system reliability.

[0078] 2.3 Switch driver module

[0079] The switch driver module is used to control the switch device in the load switch control module.

[0080] When the input positive and negative DC dual voltage is in the form of positive voltage VCC connected to point A, reference voltage GND connected to point B, and negative voltage VCC- connected to point C:

[0081] Pin 1 of optocoupler E1 is connected to the cathode of diode V1, pin 2 of optocoupler E1 is connected to pin 1 of optocoupler E2, pin 3 of optocoupler E1 is connected to the base of switch Q1, and pin 4 of optocoupler E1 is connected to the cathode of diode V1. Pin 2 of optocoupler E2 is connected to pin 1 of voltage reference power supply V8, pin 3 of optocoupler E2 is connected to the base of switch Q2, and pin 4 of optocoupler E2 is connected to the cathode of diode V4. That is, when voltage reference power supply V8 turns on, optocouplers E1 and E2 are turned on, which in turn turns on their primary terminals, ultimately controlling switch Q1 and Q2.

[0082] The positive electrode of the Zener diode V7 is grounded, and the negative electrode of the Zener diode V7 is connected to the positive voltage VCC through the diode V1. In other words, the Zener diode V7 clamps the primary input voltage of the optocoupler E1 and the optocoupler E2 to prevent damage to the optocoupler E1 and the optocoupler E2 due to excessive input voltage.

[0083] Resistors R1 and R3 are connected in series between the cathode of diode V1 and pin 1 of optocoupler E1. They control the primary input current of optocouplers E1 and E2, keeping them operating in a saturated conduction state. They also divide the voltage in series to prevent breakdown caused by a single resistor's low withstand voltage.

[0084] Resistors R2 and R4 are connected in series and in parallel with Zener diode V3. The cathode of Zener diode V3 is connected to pin 4 of optocoupler E1. The voltage divider created by resistors R2 and R4, combined with the clamping voltage of Zener diode V3, prevents damage to the secondary input of optocoupler E1 due to excessive input voltage.

[0085] The resistor R5 is connected to the base of the switch tube Q1 , that is, the resistor R5 drives the switch tube Q1 to limit the current.

[0086] Resistor R7 and capacitor C1 are connected in parallel to the base of switch Q1. That is, the pull-down resistor R7 and the filter capacitor C1 together ensure that the driving level of switch Q1 is stable.

[0087] Resistors R8 and R9 are connected in series and in parallel with Zener diode V6. The cathode of Zener diode V6 is connected to pin 4 of optocoupler E2. In other words, the voltage divider of resistors R8 and R9 and the clamping of Zener diode V6 work together to prevent damage to the secondary input voltage of optocoupler E2 due to excessive voltage.

[0088] The resistor R10 is connected to the base of the switch tube Q2, that is, the resistor R10 drives the switch tube Q2 to limit the current.

[0089] Resistor R11 and capacitor C3 are connected in parallel to the base of switch Q2. That is, the pull-down resistor R11 and the filter capacitor C3 together ensure the stable driving level of switch Q2.

[0090] 2.4 Load switch control module

[0091] The load switch control module is used to control the on or off of the load power supply.

[0092] Furthermore, a freewheeling diode V2 is connected in parallel with the electronic control device K1; a freewheeling diode V5 is connected in parallel with the electronic control device K2. That is, the freewheeling diodes V2 and V5 are used for freewheeling protection in the event of a power failure in the wiring harness of the electronic control devices K1 and K2, preventing the wiring harness from burning out.

[0093] Under the premise that the current protection circuit based on a single power supply system cannot effectively judge the input of the positive power supply and the reference power supply, and thus cannot realize the anti-reverse connection protection of the positive and negative DC power supplies, the utility model can cut off the load power supply when the power input is connected incorrectly under the conditions of positive and negative DC dual voltage input, thereby realizing the anti-reverse connection protection function; at the same time, the minimum undervoltage protection function can be realized by adjusting the resistance value of the matching resistor, and the load power supply circuit can be cut off when the input voltage is too low; in addition, the device has complete protection such as current limiting, overvoltage, and anti-interference, and has strong applicability, which can meet the application of various voltage systems and strong electromagnetic interference environments.

[0094] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A positive and negative DC dual voltage input reverse polarity protection control circuit, the circuit having a positive voltage VCC, a reference voltage GND, and a negative voltage VCC-, wherein in the normal input form of the circuit, the point where the positive voltage VCC is connected is point A, the point where the reference voltage GND is connected is point B, and the point where the negative voltage VCC- is connected is point C, characterized in that: The circuit further includes a polarity determination module, a voltage determination module, a switch driving module and a load switch control module, wherein: The polarity determination module includes a diode V1, a diode V4, and a diode V9; the polarity determination module determines all forms of power polarity access at points A, B, and C through the unidirectional conductivity of the diodes V1, V4, and V9; The voltage judgment module includes a resistor R6, a resistor R12, and a voltage reference power supply V8. The voltage judgment module adjusts the resistance values ​​of the resistors R6 and R12 connected in series so that when the voltages at points A and C meet the condition |VCC-|<VAC≤(VCC+|VCC-|), the reference voltage of the voltage reference power supply V8 reaches a regulated voltage. In combination with the polarity judgment module, the uniqueness of the power polarity access at points A, B, and C can be determined. The switch driving module is used to control the switch device in the load switch control module; The load switch control module is used to control the on or off of the load power supply.

2. The positive and negative DC dual voltage input anti-reverse connection protection control circuit according to claim 1, characterized in that: The load switch control module includes an electronic control device K1 and an electronic control device K2; wherein: The anode of the diode V1 is connected to the positive voltage VCC, and the cathode of the diode V1 is connected to the electronic control device K1. The diode V1 allows the point A to only be connected to the positive voltage VCC or the reference voltage GND. The anode of the diode V4 is connected to the reference voltage GND, and the cathode of the diode V4 is connected to the electronic control device K2. The diode V4 allows the point B to only be connected to the positive voltage VCC or the reference voltage GND. The anode of the diode V9 is connected to pin 3 of the voltage reference power supply V8, and the cathode of the diode V9 is connected to the negative voltage VCC-. Through the diode V9, point C can only be connected to the reference voltage GND or the negative voltage VCC-.

3. The positive and negative DC dual voltage input anti-reverse connection protection control circuit according to claim 2, characterized in that: The load switch control module further includes a switch tube Q1, a switch tube Q2, a freewheeling diode V2 and a freewheeling diode V5; wherein the freewheeling diode V2 is connected in parallel with the electronic control device K1; and the freewheeling diode V5 is connected in parallel with the electronic control device K2.

4. The positive and negative DC dual voltage input anti-reverse connection protection control circuit according to claim 3, characterized in that: The switch driving module includes an optocoupler E1, an optocoupler E2 and a voltage regulator diode V7, wherein: Pin 1 of the optocoupler E1 is connected to the cathode of the diode V1, pin 2 of the optocoupler E1 is connected to pin 1 of the optocoupler E2, pin 3 of the optocoupler E1 is connected to the base of the switch tube Q1, and pin 4 of the optocoupler E1 is connected to the cathode of the diode V1; Pin 2 of the optocoupler E2 is connected to pin 1 of the voltage reference power supply V8, pin 3 of the optocoupler E2 is connected to the base of the switch tube Q2, and pin 4 of the optocoupler E2 is connected to the cathode of the diode V4; The anode of the voltage stabilizing diode V7 is grounded, and the cathode of the voltage stabilizing diode V7 is connected to the positive voltage VCC through the diode V1 .

5. The positive and negative DC dual voltage input anti-reverse connection protection control circuit according to claim 4, characterized in that: The switch driving module further includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a capacitor C1, a capacitor C3, a voltage stabilizing diode V3, and a voltage stabilizing diode V6; wherein, The resistor R1 and the resistor R3 are connected in series between the cathode of the diode V1 and pin 1 of the optocoupler E1; The resistor R2 and the resistor R4 are connected in series and then in parallel with the voltage stabilizing diode V3. The cathode of the voltage stabilizing diode V3 is connected to the 4th pin of the optocoupler E1. The resistor R5 is connected to the base of the switch tube Q1; The resistor R7 is connected in parallel with the capacitor C1 and then connected to the base of the switch tube Q1; The resistor R8 and the resistor R9 are connected in series and then connected in parallel with the voltage stabilizing diode V6. The cathode of the voltage stabilizing diode V6 is connected to the 4th pin of the optocoupler E2. The resistor R10 is connected to the base of the switch tube Q2; The resistor R11 and the capacitor C3 are connected in parallel and then connected to the base of the switch tube Q2.

6. The positive and negative DC dual voltage input anti-reverse connection protection control circuit according to claim 1, characterized in that: The voltage judgment module further includes capacitors C2 and C4; wherein: The resistor R6 is connected in series with the resistor R12 and then connected in parallel with the capacitor C2, and connected to the cathode of the diode V1 and the anode of the diode V9. The capacitor C2 is used to filter out high-frequency interference of the power input; The resistor R12 and the capacitor C4 are connected in parallel and then connected to pin 2 of the voltage reference power supply V8. The capacitor C4 is used to filter out interference at the reference voltage of the voltage reference power supply V8.

7. The positive and negative DC dual voltage input anti-reverse connection protection control circuit according to claim 1, characterized in that: The voltage reference power supply V8 is a precision shunt regulator.

8. The positive and negative DC dual voltage input anti-reverse connection protection control circuit according to claim 3, characterized in that: The switch tubes Q1 and Q2 may be triodes, MOS tubes, or IGBTs, and are used to control the on and off of the electronic control devices K1 and K2.

9. The positive and negative DC dual voltage input anti-reverse connection protection control circuit according to claim 2, characterized in that: The electronic control devices K1 and K2 may be relays or contactors, and are used to control the on or off of the power supply to the load.

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