555 timing cicuit need help

Discussion in 'General Electronics Chat' started by steve7486, Aug 3, 2010.

  1. steve7486

    Thread Starter New Member

    Aug 3, 2010
    hi all

    there is more than likly a circuit out there for what i want to do. i have an inverter project that i'm working on that has a 12V draw of about 1000 amps. the 12V side is more than capable of handeling this but is shuting down the low voltage protection on start up. i need a simple cicuit using a 555 timer that will hold the output low for 30 seconds and then keep the output high untill the inverter is turned off, to give the 12V side time to power up properly before allowing the inverter to draw any current. i alredy have the mosfets to handel the current draw for switching on and off.

    thanks steve
  2. soda

    Senior Member

    Dec 7, 2008
    This is a mono stable you can use. Just calibrate the pre-set for 30sec. If you want to use a transistor then replace the relay with a PNP transistor
    You can also use the relay by connecting your devise to the normal close contact of the relay and then place the relay between pin 3 and 0v