Basic 12V 3 second on timer

I'm a bit of a novice when it comes to electronics and such. I do know how to test circuits (basic), use a Fluke Meter and such.

What I am trying to do is make a 12V timer (12v in and 12V Relay trigger (or a relay that can handle whatever output voltage and pass a 12V 20 amp load) with a 3 second duration. I'd like to be able to hook this up to a switch and use it as a one touch operation. With that I mean to just push the switch and let it go and let the circuit run for approximately 3 seconds then turn itself off. If possible to add a pot to the circuit to be able to adjust the time would be helpful.

From some basic research it seems easy enough but Nothing wrong with asking from those that know.

Thanks for your help.

Rich

This is such a common request that they actually make relays that do this exact thing. They are called "Time Delay Relays" and are readily available from Newark, Digikey and other electronics suppliers in a variety of styles, operating voltages, contacts, duration, etc. Search on "Time Delay Relays" and TDR.

Really? I'll google it. However if you've got a couple of part numbers or recommend one over another I'd appreciate the input.

Thank you again

Here's one for about $60, runs on 12V, handles 10A -

Digi-Key - 646-1191-ND (Crouzet C/O BEI Systems and Sensor Company - 88867100)

You would select the 10S range, turn the knob to 3 seconds, set the function to "B" which is for a "one-shot" operation. It has a stupid octal base (most of them do) so you may need to buy a socket (there's a part number on the spec sheet for it).

Thanks Duffy. I'm familiar with the octal bases. ZF Mathers uses them on their electronic controls for clutch and throttle on boats. Thanks for all your help.

Rich