change polarity@15 mins on DC transformer<total beginner--single project>

how much current do you need?

Bye. Jasen

Thanks for this most interesting reply--would like to follow this amazing stuff up when I get a chance--have bookmarked it.

In fact, you could use one of those common 24 hour mains timers - some of them have plastic lugs at 15 minute spacings so you just need to push in every second lug, and use it to power a low-voltage plugpack that energises the relay.

Nice solution.

Dave :)

Sorry bout the delay, i been locked up on jury duty.

I still dont know what you a driving. Obviously not a motor. I suggest that you use the simplest solution suggested by others, which is a relay. As for the timer, if you know nothing about electronics, then i suggest you use a manufactured timer from your local electrical distributer. Alternativley, Jaycar or Altronics (IIRC) used to sell pre built kits, i cant remember which, but i suggest you peruse there range. That is providing that they are still sold. Perhaps others here can confirm,

Maybe the OP is onto something that he chooses not to reveal. Fair call I say.