Overvoltage Protection for the LM317


Posted on Sep 3, 2012

This is an add-on Over Voltage Circuit for the LM317 Regulator Circuit submitted by Matthew Hewson. It is a voltage regulator that allows a 6v portable supply to be derived from the 12v car battery. You can add a 6.2V zener diode and a LED to warn you when the input supply is overvoltage. If you could find a relay that would operate from 6.2v right up to 12v that you could connect in such a way that if over voltage occurred, then the relay would automatically switch off the output preventing damage to any connected equipment.


Overvoltage Protection for the LM317
Click here to download the full size of the above Circuit.

Such a relay would be quite difficult to find, so I designed this, it is a simple two transistor circuit which will switch off the output should the voltage raise above 6.2v (this can be changed by selecting a different value of zener diode ). Double c




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Infrared cordless Headphone Amplifier
    Car Battery Charger
    Reversing motor drive dc control
    Regulated-driven-converter
    8051 USB PROGRAMMER
    GS500 Horn
    vna usb
    Four channel RF remote control
    Industrial & Domestic Electronic Kits
    Transmit Audio Cable
    Practical flip-flop circuit
    Two-channel speaker protection schematic
    Emitter negative feedback differential amplifier gain control circuit



    Top