I hope this is the correct place to post this as its my first post but having not done any component level hands on electronics for over 2 decades I have found myself struggling with some fairly basic concepts so any help would be gratefully recieved

I want a circuit that will when power is applied allow that power to pass through for about 2-4 seconds after which it will stop allowing the voltage to pass until the circuit is powered down and repowered again.

I have been trying some variations on 555 and transistor circuits but the component counts have grown and grown to the point where I am hoping there is a simpler method I either havent found or cant remember that I have overlooked

The load draws 200-300 milliamps so I was wondering if I could even just do this with a CR circuit or whether that would always leak some current through. The other possibility I was wondering about is whether its possible to place a CR circuit on the emitter of a transistor that was biased to switch on instantly, which would then bias the base over the CR time to switch it off after the 2-3 second or so time period

The motor I need to power takes the same kind of current as a dashboard light so thats what I have been using to try and prototype this. And all the circuit needs to do is just allow the 12v signal to pass for around 2-4 seconds after the engine starts then stop passing that voltage for as long as the car is running nothing more

So circuits involving 10-15 components "feel" far more complex than should be needed although I also accept that after not playing on this level for so long my "gut" might be flawed but I thought I would ask anyway on the offchance somebody else has already created a circuit to do a similar task

Thank you in advance for any help/suggestions offered

Mike

Yes it looks like it would do that but I checked the price and its around $30 dollars worth of hardware to replace around $5 worth of normal components

At the moment I'm looking at a toss up between a 555 timer or a monostable transistor circuit driving a drive transistor to power the load and was really just wondering if there was a simpler cheaper approach that was lower tech rather than higher tech that would do the same task.

But thank you for suggesting that module, I have to admit its something I have never even seen before and it certainly looks worth reading up on incase I have another project later on that would justify the cost of one of those as it looks pretty cool and versatile