CN208461460U - A kind of vehicle-mounted accessory power supply reverse-connection protection circuit - Google Patents

Abstract

The utility model discloses a kind of vehicle-mounted accessory power supply reverse-connection protection circuits; with vehicle electronic circuit interface and auxiliary power interface; the vehicle electronic circuit interface anode connection auxiliary power interface anode; power switch is concatenated between vehicle electronic circuit interface cathode and auxiliary power interface cathode; polarity discriminating module is concatenated between vehicle electronic circuit interface positive and negative electrode or between auxiliary power interface positive and negative electrode, polarity discriminating module controls the on-off of power switch according to the electric power polarity detected；The utility model uses the technical solution that switch mosfet pipe carries out counnter attack; in the case of loss and baby battery power shortage can be effectively reduced, due to the presence without obvious diode drop; it still is able to be supplied to Vehicular charger or the higher voltage of vehicle-mounted DC-DC, there is stable defencive function.

Description

A kind of vehicle-mounted accessory power supply reverse-connection protection circuit

Technical field

The utility model relates to electric car charging technique field more particularly to a kind of Vehicular chargers or vehicle-mounted DC- The accessory power supply reverse-connection protection circuit of DC.

Background technique

With energy-saving and emission-reduction, and the demand of control atmosphere pollution, new-energy automobile is gradually commercial in market, and electronic vapour Vehicle is even more the main force of new-energy automobile.Electric car is divided into pure electric automobile and mixed electrical automobile again, wherein Vehicular charger and Vehicle-mounted DC-DC is component part important in electric car.Vehicular charger and vehicle-mounted DC-DC use outer low pressure battery Auxiliary power supply is provided, outer low pressure battery is because natural aging or failure and other reasons need replacing maintenance, if not using has The anti-reverse design of effect, will cause the damage of vehicle electronic circuit.The mode that industry generallys use at present is the direct counnter attack of diode Scheme, but the program haves the defects that diode drop is big, energy consumption is high.So needing to develop in the industry, a kind of energy consumption is small, guarantee degree High vehicle-mounted accessory power supply reverse-connection protection circuit.

Utility model content

The utility model is the defect that prior art pressure drop to be solved is big, energy consumption is high, proposes that a kind of energy consumption is small, guarantee degree is high Vehicle-mounted accessory power supply reverse-connection protection circuit.

In order to solve the above technical problems, the utility model proposes technical solution be to design a kind of vehicle-mounted accessory power supply reversal connection Circuit to be protected, there is vehicle electronic circuit interface and auxiliary power interface, vehicle electronic circuit interface anode connects auxiliary power interface anode, Power switch is concatenated between vehicle electronic circuit interface cathode and auxiliary power interface cathode, between vehicle electronic circuit interface positive and negative electrode Or polarity discriminating module is concatenated between auxiliary power interface positive and negative electrode, polarity discriminating module is according to the power supply pole detected Property control power switch on-off.

The power switch uses switch mosfet pipe, and source electrode connects the vehicle electronic circuit interface cathode, its drain electrode meets institute State auxiliary power interface cathode, its grid connects the polarity discriminating module.

The polarity discriminating module includes being serially connected in the vehicle electronic circuit interface anode and the switch mosfet tube grid Between the 7th resistance, and two pole of pressure stabilizing being connected in parallel between switch mosfet tube grid and the vehicle electronic circuit interface cathode Pipe, the 6th resistance, the 4th capacitor, wherein the anode of the zener diode connects the vehicle electronic circuit interface cathode, cathode connects Connect the switch mosfet tube grid.

Tandem electric inductance L5 between the anode of the vehicle electronic circuit interface and the anode of auxiliary power interface.

Filter capacitor module is connected between the positive and negative electrode of the auxiliary power interface.

The filter capacitor module includes first be connected in parallel between auxiliary power interface anode and cathode, the Two, third capacitance group, the first capacitor group include the second capacitor and the 5th capacitor being cascaded, second capacitance group Including the third capacitor and the 6th capacitor being cascaded, the third capacitance group includes the 7th electricity being sequentially connected in series together Appearance, the 8th capacitor, the tenth capacitor and the 9th capacitor, wherein the tie point of the 8th capacitor and the tenth capacitor is grounded

Compared with prior art, the utility model uses the technical solution that switch mosfet pipe carries out counnter attack, Ke Yiyou In the case of effect reduces loss and baby battery power shortage, due to the presence without obvious diode drop, it still is able to be supplied to vehicle-mounted fill Motor or the higher voltage of vehicle-mounted DC-DC have stable defencive function.

Detailed description of the invention

Fig. 1 is the functional block diagram of the utility model preferred embodiment；

Fig. 2 is the circuit diagram of the utility model preferred embodiment.

Specific embodiment

In order to make the purpose of the utility model, technical solutions and advantages more clearly understood, below in conjunction with attached drawing and implementation Example, is described in further detail the utility model.It should be appreciated that specific embodiment described herein is used only for explaining this Utility model is not used to limit the utility model.

The utility model discloses a kind of vehicle-mounted accessory power supply reverse-connection protection circuit, referring to functional block diagram shown in fig. 1, Auxiliary power interface with the vehicle electronic circuit interface and connection baby battery that connect interior electric appliance, it is auxiliary that it is polar, which to be easy wrong, Power interface.Vehicle electronic circuit interface anode 12V+ connection auxiliary power interface anode KL30, vehicle electronic circuit interface cathode PGND with Power switch is concatenated between auxiliary power interface cathode J_KL_31, between vehicle electronic circuit interface positive and negative electrode or in auxiliary electricity Polarity discriminating module is concatenated between source interface positive and negative electrode, polarity discriminating module is opened according to the electric power polarity control power supply detected The on-off of pass.Such as the non-wrong of accessory power supply (baby battery) polarity, the conducting of polarity discriminating module drive power switch, baby battery is to vehicle Carry circuit power supply；If electric power polarity is reversed, polarity discriminating module drive power switch cut-off, baby battery is separated with vehicle electronic circuit, Vehicle electronic circuit is protected.

In the preferred embodiment, the power switch uses switch mosfet pipe Q1, and source electrode connects the vehicle electronic circuit and connects Mouth cathode, its drain electrode connect the auxiliary power interface cathode, its grid connects the polarity discriminating module.Switch mosfet pipe is led Internal resistance is extremely low when logical, and electric current is little in circuit in addition, so the pressure drop of switch mosfet pipe is extremely low, can be neglected.In small electricity In the case of the power shortage of pond, due to the presence without obvious diode drop, still be able to be supplied to Vehicular charger or vehicle-mounted DC-DC compared with High voltage.

Referring to Fig. 2 shows preferred embodiment, the polarity discriminating module include be serially connected in the vehicle electronic circuit interface just The 7th resistance R7 between pole and the switch mosfet tube grid, and be connected in parallel on switch mosfet tube grid with it is described vehicle-mounted Zener diode D1, the 6th resistance R6, the 4th capacitor C4 between circuit interface cathode, wherein the anode of the zener diode Connect the vehicle electronic circuit interface cathode, cathode connects the switch mosfet tube grid.When correct for electrical bonding, Q1 by KL30 is driven, in the conductive state, and baby battery is powered to vehicle electronic circuit；When for electrical bonding mistake, the driving of Q1 does not have Power supply is in off state, and diode also ends naturally in vivo, and baby battery cannot power to vehicle electronic circuit.

Tandem electric inductance between the anode of the vehicle electronic circuit interface and the anode of auxiliary power interface in the preferred embodiment L5.L5 can be in powered on moment limit inrush currents, anti-current impact.

In the preferred embodiment, filter capacitor module is connected between the positive and negative electrode of the auxiliary power interface.Filter capacitor Module can effectively filter power supply, improve power supply stability.

Referring to Fig. 2, the filter capacitor module includes being connected in parallel between the auxiliary power interface anode and cathode The first, second, third capacitance group, the first capacitor group includes the second capacitor C2 and the 5th capacitor C5 being cascaded, Second capacitance group includes the third capacitor C3 and the 6th capacitor C6 being cascaded, and the third capacitance group includes successively going here and there The 7th capacitor C7, the 8th capacitor C8, the tenth capacitor C10 and the 9th capacitor C9 being linked togather, wherein the 8th capacitor C8 and the tenth The tie point of capacitor C10 is grounded.

Above embodiments are by way of example only, non-to provide constraints.It is any without departing from the application spirit and scope, and to it The equivalent modifications or change of progress, shall be included in the scope of claims of this application.

Claims (6)

1. A vehicle-mounted auxiliary power supply reverse connection protection circuit, with a vehicle-mounted circuit interface and an auxiliary power supply interface, is characterized in that: the vehicle-mounted circuit interface positive pole is connected to the auxiliary power supply interface positive pole, and the vehicle-mounted circuit interface negative pole and the auxiliary power supply interface negative pole are connected in series with a power switch , A polarity discrimination module is connected in series between the positive and negative poles of the vehicle circuit interface or between the positive and negative poles of the auxiliary power supply interface, and the polarity discrimination module controls the on-off of the power switch according to the detected power supply polarity. 2. The vehicle-mounted auxiliary power supply reverse connection protection circuit according to claim 1, wherein the power switch adopts a MOSFET switch (Q1), the source of which is connected to the negative electrode of the vehicle-mounted circuit interface, and the drain of which is connected to the The negative pole of the auxiliary power supply interface and the gate thereof are connected to the polarity discrimination module. 3 . The vehicle-mounted auxiliary power supply reverse connection protection circuit according to claim 2 , wherein the polarity discrimination module comprises a seventh serial connection between the vehicle-mounted circuit interface anode and the MOSFET switch gate. 4 . A resistor (R7), and a Zener diode (D1), a sixth resistor (R6), and a fourth capacitor (C4) connected in parallel between the gate of the MOSFET switch tube and the negative electrode of the on-board circuit interface, where the Zener diode The anode is connected to the negative electrode of the vehicle circuit interface, and the cathode is connected to the gate of the MOSFET switch tube. 4 . The vehicle-mounted auxiliary power supply reverse connection protection circuit according to claim 1 , wherein an inductor ( L5 ) is connected in series between the positive pole of the vehicle-mounted circuit interface and the positive pole of the auxiliary power supply interface. 5 . 5 . The vehicle-mounted auxiliary power supply reverse connection protection circuit according to claim 1 , wherein a filter capacitor module is connected between the positive and negative poles of the auxiliary power supply interface. 6 . 6 . The vehicle-mounted auxiliary power supply reverse connection protection circuit according to claim 5 , wherein the filter capacitor module comprises first, second and third capacitors connected in parallel between the positive and negative electrodes of the auxiliary power interface. 7 . The first capacitor group includes a second capacitor (C2) and a fifth capacitor (C5) connected in series, and the second capacitor group includes a third capacitor (C3) and a sixth capacitor (C6) connected in series ), the third capacitor group includes a seventh capacitor (C7), an eighth capacitor (C8), a tenth capacitor (C10) and a ninth capacitor (C9) connected in series in sequence, wherein the eighth capacitor (C8) and The connection point of the tenth capacitor (C10) is grounded.