"Jason Farmer" wrote in message
...
Hi,

I need a bit of help. I have an application where I need to alter the
polarity automatcially without swapping the connections.

Currently I have a 16VDC 900mA power supply and a switch that brakes a
circuit. The first time I use the switch I need it to break +ive the next
time -ive ad infinitum.

Noramally I write software so I can see this shouldn't be hard, I just
don't
know what I need to accomplish this!

TIA
Jason Farmer



Try a garage-door opener control circuit.