You mention using a FQP30N06L which is a N channel MOSFET (Logic Level) but you mention a PNP transistor? Not sure about that? Anyway using a FQP30N06L MOSFET you would configure the 555 timer as a "one shot" so you get a 20 second (approximately) pulse out when triggered. This can be a retriggerable or non retriggerable one shot. You have water sloshing around in the bilge. The difference between retriggerable and non retriggerable is when the bilge switch turns on the retriggerable one shot will maintain a logic high (pump running) as long as the bilge switch is ON/Off from sloshing. Once the switch is Off and remains Off the pump will run for an additional 20 seconds. Non retriggerable once triggered the pump will run for 20 seconds regardless of what the switch is doing. Once it times out it waits for another trigger.want to use a 555 timer to switch a PNP transistor on for 20 seconds.
I do not know how to wire it
Can someone point me in the direction of a circuit, please
I wired up the circuit above and on pin 3 of the 555 timer I get power only when the pushbutton is depressed. let go of the switch and no voltage on pin 3
Checked wiring and its correct.
I'm under the assumption that when using the p channel (FQP27P06) that I have to apply neg voltage to the gate for the circuit to turn on (switching the positive side)
Even if the timer was to stay on. Pin 3 is positive