Hi Jim,
 
JB> I was only going to use the parallel port line as a driver for the rel
 
I'm not sure about solid state relays, but I know the mechanical type
ones have a coil in them, and when you apply power it will become an
electromagnet, which then attacts 'switch' part and closes circuit. 
The coil will have some resistance, and using Ohm's law can calculate
the current.  For example, if coil resistance is 75 ohms, and voltage
is 5v, then 5/75 = 66 ma, which may be too much for those open
collector outputs on the parallel port.  
 
JB> Could you give me some direction as to where I can get technical info 
JB> aspect. I am a good chemist....pretty good salesman....not-a-bad
JB> programmer....but very limited when it comes to electronics (but learn
JB> fast :-)
 
hmmmm....there is a book out called "interfacing to the ibm-pc", up to
version 2.  its put out by Sam's books.  I bought it from an outfit
called JDR here in the states, their # is (800) 538-5000 or (408)
494-1400.  i think they are asking $20 or something for it, well worth
it.  other than that, most of my knowledge just came from reading lots
& lots of electronic magazines and thru trial and error.  but i
remember when i got that book thinking 'wish i had it way back when'
and still reference it from time to time.  
 
I'll try to remember to email you that faq, if I forget email me and
that will jog my memory.  The file is still stored on that account so
its real easy to attach it back to you (and even easier if I just have
to hit reply...).            Eric
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