Short to ground sensor

Discussion in 'General Electronics Chat' started by John5788, Aug 14, 2009.

  1. John5788

    Thread Starter Active Member

    Apr 2, 2009
    54
    0
    anyone know of a way to design a circuit to detect a 12V short to ground? is there an easy way to do this with some sort of IC? I'd like to be able to detect the short and then signal an MCU about the short to ground.

    i'm thinking kind of like a fuse/circuit breaker, but signals the MCU about the fault, instead of breaking the circuit.
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    The usual detector for such a short is a blown fuse. A short circuit is usually accompanied by an uncontrolled current, causing damage to the power source and circuit elements.

    You might do something like fuse branches off the main supply line for isolation short of total system shutdown. Notifying a microcomputer that a 12 volt line has gone to 0 and a high current is flowing will not effectively limit damage.

    Or do you have some special application in mind?
     
  3. ELECTRONERD

    Senior Member

    May 26, 2009
    1,146
    16
    Couldn't you just have an LED that would light up. Without ground it won't light up and when the ternimal is shorted to ground it will light up the LED.
     
  4. stanford007

    New Member

    Aug 14, 2009
    7
    0
    I think John has a specific application in mind. To assist, we need more info. You could for example, place a high wattage low value resistor in series with 12V supply and monitor the votage across. High Currect due to short wil lgive higher voltage drop across resistor. You could also put a current limiter and if there is a short, you will limit current and notify MCU.
     
  5. russ_hensel

    Well-Known Member

    Jan 11, 2009
    818
    47
    When the 12 volts is connected to ground it will drop to 0. Just measure the voltage, or if the power supply is very stiff, measure the light from the explosion.
     
  6. Justpassinthru

    New Member

    Aug 13, 2009
    4
    0
    How about a normally open relay on the load side of the fuse so that when the overcurrent occurs the fuse opens the circuit, closes the relay, which then powers an indicator light or other trigger.
     
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