Re: Relay controlled by parallel

Chris,
The cheapest way is to buy a used solid state relay. They
have four terminals on them. The input is 3 to 24 volts DC and you
can hook it right on the parallel port. Inside there is a LED with
resistor. Across from that is a TRIAC. When the pin on you parallel
port goes high the diode lights turning on the TRIAC. You can reverse
the leads if you want it to work the other way. Check
ALLelectronic.com they carry solid state relays. Just make sure your
software supports relays. You can experiment by using a LED with a
1K resistor in series. Just remember the LED has a NEG and a POS
lead. So does the relay.

Bob

--- In CAD_CAM_EDM_DRO@y..., cclough@x wrote:
> Hi all,
> Thanks a million for all your info... have yet another question.
How
> hard would it be to control a relay from the parallel port; using a
G-
> code command. I am trying to use a plasma torch; and upon sending
the
> signal to the relay, it'll turn the plasma on.
> Any thoughts?
> -Chris Clough
> Xtech Engineering