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Help a noob (timer circuit)

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tjchad04

New Member
Hello,
I've done some reading all over the place for quite some time now but I am frustrated and in over my head. Hopefully someone can point me in the right direction.

My project: I am going to wire a rear window defroster in my car. I need help designing the control circuit for the low amp side of the relay that will engage and send power to the defroster. This circuit needs to be initiated by a momentary pulse from a push button, and then on a 10 minute timer. I would like to use this kit, but am not attached to it by any means. Mini Electronic Timer Kit - 2 seconds to 10 minutes

While the timer is counting down, and button is pulsed again, the defroster needs to go off, otherwise go off when the timer runs out. After that, the whole circuit needs to return to its original state. The power for the circuit will be on one of the vehicles ignition circuits, meaning it will only be powered when the ignition is on. So when the ignition comes on, and thereby supplies the flip flop (or whatever makes the latching behavior) with power, it needs to be at a state where it is not powering the timer circuit until the power button is pushed.

Hopefully I've been clear here. Please HELP! :D
 

Boncuk

New Member
Hi Tjchad04,

that circuit won't fit your needs. It activates the output if power is applied and deactivates it when it times out or power is removed.

If I understood correctly you want to start defrosting by pushing a button. Hitting the button the second time defrosting should be terminated - or when the circuit times out if no button is pushed.

Is that correct?

Boncuk
 
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