Is it possible to have some kind of timer added to an electronic switch so that I can have the device run for say 30 seconds and shut off by itself?

KayTracy posted plans like that about a year ago. I don't remember the topic, but try a search on that name.

The kit below will do more or less exactly what you need - it says it runs off 12 volts, but at a push it will run off a 9 volt PP3.

I've used a few of these over the years, although in ALL my projects I have had to alter the circuit to swith something ON after a predetermined delay - possible but not at all easy!



http://www.vellemanusa.com/us/enu/product/view/?id=350494

Thanks for the suggestions!

If you are looking to run something for just a brief time ( 10 - 60 secs. ) then shut off or start an electronic item with the same delay length, a cool timer/switch is the model 90 pneumatic timer by Eagle Signal. This is really an air tank type unit with an adjustable thumbwheel for setting the time length to either start or stop anything wired in series. When the air basically runs out in the 'tank', the two metal leads touch and complete the circuit. This is a nice, reliable way to go. If you need further assistance - pm me.

Chuck