Opto-isolated Parallel Port Driven Relays

A few months back, I made a parallel port driven relay box for Engineer 2007 with four outputs which were opto-isolated from my PC. Since I didn't have opto-isolators, I built my own by taping LED/photoresistor pairs together. It worked perfectly.

(Circuit details: http://www.epanorama.net/circuits/parallel_output.html)

I also combined it with laser gesture recognition to turn four appliances on or off using a laser pointer for Engineer 2007. I guess everyone loved it. :)

If you can make pcbs, and are interested in a simple little circuit to provide opto-isolator protection to 4 parallel port inputs, and relays on the other 4 bits, as outputs, then check the offer on....

http://www.arunet.co.uk/tkboyd/ele1pp.htm

... which is a little way down the page, next to the Google panel, in the paragraph starting "I have a third generatino, inexpensive...".