turn circuit off and on??

[Boner the Cat]

HI all,

I have a requirement to turn a simple circuit off/on at different intervals
and want to use my computer to do this.

the circuit is low amp 12v (relay)

would it be possible to be able to set it to turn off/on at say;
3 hours of 30sec. on / 30sec.off??

what is available for FREE sw. and devices.

thks
bg

starpath(nooospm)@tampabay.rr.com


--
"Not everything that can be counted counts, and not everything that counts
can be counted. "
Albert Einstein (1879-1955)

[Chuck Y]

well, you don't mention your skills, but you
might pull off something via a parallel port or
serial port pin.

I'd run it through a MOC3010 (optoisolator) for protection,
to a transistor to give enough power to throw a relay.

Should cost you a wall wart, $5 of parts and stuff to
put it on (circuit board scrap) and in (lunch box?).

weeder technology (http://weedtech.com) has a serial controlled
16 port digital IO board that's simple to attach to a relay and you
can run it 1000 feet away over RS-232 over CAT5 that would be
cheaper if your time is worth anything.

It's more flexible and can be lots of fun to play with for around $60.
You send it commands in ASCII. So a simple "echo command > /dev/ttyb"
can turn on the device. ('print command > COM2:' in DOS-land).

Boner the Cat wrote: HI all, I have a requirement to turn a simple circuit off/on at different intervals and want to use my computer to do this. the circuit is low amp 12v (relay) would it be possible to be able to set it to turn off/on at say; 3 hours of 30sec. on / 30sec.off?? what is available for FREE sw. and devices. thks bg starpath(nooospm)@tampabay.rr.com