Anti-surge device of on-vehicle power supply

Abstract

The invention discloses an anti-surge device of an on-vehicle power supply, which relates to the accessory equipment of a direct current power supply. The end D of an MOS transistor of an N channel of the anti-surge device is connected with the power supply of a vehicle, while an end S supplies direct current output to a load; a charging pump circuit is arranged between the ends S and D of the MOS transistor so as to supply a driving voltage to an end G; a starting circuit is arranged between the ends D and G of the MOS transistor and supplies an initial driving voltage to the end G when the power supply of the vehicle supplies an input voltage to start the anti-surge device; a clamping circuit is arranged between the end G of the MOS transistor and a ground wire, controls the output of the end S to be slightly lower than a clamping voltage when the voltage of the end D is higher than the clamping voltage and lower than a turn-off voltage and controls the output of the end S to be slightly lower than the voltage of the end D when the voltage of the end D is lower than the clamping voltage; an over-voltage protection circuit is arranged between the end D of the MOS transistor and the ground wire; and the output end of the over-voltage protection circuit is connected with the end G of the MOS transistor to control the MOS transistor to cut off the output of the end S when the voltage of the end D is higher than the turn-off voltage. The anti-surge device solves the problem on the resistance to the impact of continuous high surge voltages.

Description

technical field [0001] The invention relates to a direct current power accessory device. Background technique [0002] The car power supply consists of a battery and a generator. During the use of the car, there is a car surge voltage (transient), which is random and repeatable. Repetitive transients (such as engine cranking) can generate voltages of hundreds of volts. For automotive electronic components, the most severe transients come from load dumps. Load dump is a rapid energy discharge. When the generator provides charging current to the load, the sudden release of energy caused by the rapid disconnection of the battery is the load dump. Additionally, due to the use of batteries stacked in series, an overvoltage condition can be created when the car is cranked. Other transients can arise from ignition system noise, relays opening and closing, and monostable events such as blown fuses. Due to the transients in the vehicle voltage, the load circuits powered by the ve...

AI Technical Summary

Problems solved by technology

At present, surge suppression chips with relatively high grades are often expensive and cannot withstand continuous high surge voltage impacts, and do not meet the basic safety requirements of various post-installed electronic equipment.

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