A DC power supply anti-reverse connection slow start circuit and a realization method

Abstract

A DC power supply anti-reverse connection slow start circuit and a realization method are provided. When the polarity of the input power supply is correct, the voltage division between a resistor R1 and a resistor R3 provides a positive bias voltage VT1 to a field effect transistor VT1 for conduction, the power supply supplies a load behind the field effect transistor VT1, and a regulator diode VD1 prevents the voltage division between the resistor R1 and the resistor R3 from breaking through the gate of the field effect transistor VT1 when the input voltage is too high; when the polarity of the input power supply is reversed, the voltage division between R1 and R3 provides a negative bias to VT1, VT1 is turned off, and the power supply does not supply power to the load behind it, so thatthe load behind it is prevented from being burned because of the polarity of the input power supply. A series circuit of a resistor R4 and a resistor R5 and a resistor R6 and a capacitor C2 supplies abias voltage to the field effect transistor VT2; due to the charging effect of C2, the voltage on the gate of VT2 rises slowly, which decreases the on-resistance between the source and drain of VT2 gradually, thus restraining the current impulse at the initial stage of the power supply to the load, and realizing the slow start function.

Description

technical field The present invention relates to the field of electronic circuits, in particular to a DC power supply anti-reverse slow start circuit and its implementation method, which is an electronic circuit preventing DC power supply polarity reverse connection and slow start circuit and control method. Background technique In real life, quite a few electronic circuits are powered by DC power supply, such as battery chargers, LED lighting drivers, and mobile communication equipment. It is very easy to burn out, so it is urgent to install anti-reverse protection circuit on these electronic devices to avoid damage caused by reverse polarity of DC power supply. At the same time, high reliability requirements of electronic devices should also avoid large inrush current, because large The inrush current sometimes approaches or even exceeds the withstand limit of some components in the electronic equipment, reducing the service life of the electronic equipment. The commonly...

AI Technical Summary

Problems solved by technology

Aiming at the common problem of large voltage drop and high power consumption in the existing DC anti-reverse connection circuit, the main problem to be solved by the present invention is to reduce the voltage drop and power consumption of the anti-reverse connection circuit, and reduce the inrush current when the equipment is powered on

Images