Delay Power Off Circuit

Discussion in 'The Projects Forum' started by coryfoss, Jul 1, 2011.

  1. coryfoss

    Thread Starter New Member

    Jun 17, 2011
    I am new to working with Mosfet's. What I am envisioning is I press PB1 and it should supply 9V through D2 to turn on the 555. The 555 will be triggered by C4 sending and R5. Q2 will power Q1 and keep power to the load until the 555 times out. All the mosfets will be Logic Level. The LT1763 is a 5V Regulator. Is this feasible or even correct?
  2. praondevou

    AAC Fanatic!

    Jul 9, 2011
    The gate resistor R2 is only connected to the drain of Q2? In this case, when Q2 is OFF then the gate of Q1 would be floating. (not correct)

    Also, n-FETs are designed for current flow from drain to source. Q1 is drawn the other way around.

    What do you want to achieve exactly?