>I just found the circuit you meant... ;)
>But the name was ULN2003 and not ULN4003...
>So, is it just to put my PIC before the ULN2003 and the relay
after??


Andreas

Butting in on the other guy's answer :-)

Yes. But note that the "catch" diodes have a common pin for their
cathodes (pin 10 from memory).
This goes either straight to relay supply or via a resistor. If you
take it straight to supply the relays will release more slowly (which
may not be a problem). if you use a resistor there will be a voltage
spike but the relay will release more quickly.

The voltage spike will be V = Irelay x R initially, above V supply.
As long as Ispike + Vrelay supply is rather less than the rated
voltage of the ULN2003 it should work OK.

If relay release speed is not an issue then just short this pin to
relay V+ supply - its easier :-)

Note:  The ULN2003 has internal input resistors (about 3K AFAIR)
which means you can drive them directly with the PIC. Some other
similar members of the family DONT HAVE THESE RESISTORS. Be sure
which part you are using.



      Russell McMahon




>
>Andreas
>