How can I automatically cutoff power to a 12VDC circuit after about a minute, while power is still applied to it? I'm not trying to keep it powered after main power is removed, like a delay-off circuit.
This is in regard to my circuit posted here: Help with Vehicle Audio Sound Board Design
I did a web search and found a few auto-off designs, some with 555 IC timers, but wasn’t sure how to adapt them to my circuit.
Sorry, I should have clarified... I want the circuit to cutoff after a minute even though power is still applied to it. I'm not trying to keep it powered after main power is removed, like a delay-off circuit.
Is the MOSFET required? I just want power to cutoff after a minute and not come back on until source power is reset. It looks like the the circuit you mentioned goes off and on again.
Yes, the PFET is the key to such a simple circuit. The PFET will switch several Amps of current with only a small voltage drop (a few 10s of mV). There are dozens of PFETS that would work in this circuit.
I just want power to cutoff after a minute and not come back on until source power is reset. It looks like the the circuit you mentioned goes off and on again.
The circuit produces an output for a duration of ~R2*C1 each time power is applied. I did it twice in a row in the simulation to show that even a momentary interruption of the input power resets the timing network for a new cycle.