short circuit protection for balanced

Posted on Feb 4, 2014

This circuit was designed to protect a dual rail power supply from shorts across the two rails. It uses an optocoupler to monitor each supply rail, with the internal LEDs powered from ZD2 and ZD3 and the associated resistors. While the LEDs are on, the optocouplers internal transistors are both turned on which ensures that transistor Q1 is on and

short circuit protection for balanced
Click here to download the full size of the above Circuit.

relay RLY1 is energised. If either rail is short-circuited, the associated optocoupler is turned off, robbing Q1 of base current and the relay then drops out to disconnect the supply rails. Operation is restored by pressing the reset button. The value of ZD1 and the associated resistor should be chosen to suit the supply and relay coil voltages.

Leave Comment

characters left:

Related Circuits

  • New Circuits



    Popular Circuits

    13.8V/40A Stabilized high Power Supply
    Tarry light
    Analog Delay Line (Echo And Reverb)
    Schematic Diagram Wiper Speed Control Circuits
    Simple Solar Table Lamp Circuit for your Home
    Middle Frequency Equalizer with Parametric Feature
    Oscillator circuits
    Lamp Dimmer
    Chloroplast type 1 SE
    Adjustable output voltage of the series regulator circuit diagram