Re: Parallel port relay blues

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Alan Marconett <KM6VV@a...>
wrote:

> Hi Bert,
>
> Are you tying one end of the relay to +5, and the collector to the

other

> end? The output gate of the parallel port is "sinking" current in

this

> case. More current is available then "sourceing" current.
>
> Alan KM6VV

not sure what your trying to say, 5v PC power supply goes to coil
then to collector, emitter goes to ground, base to para port. had to
go down to 510ohm resistor to get 2222 to fire(took 8.2mA) using
same 5v line. 2222 would not fire with higher restance. concerned
about using lower ohm resistor to get para port to give up the 8.2mA
needed to fire 2222.
have diode across coil for suppression.

>
> bertmantx wrote:
>
> >
> > Bought bread board today and went back to drawing board.
> > I was able to get 2222 to fire but had to go to 510 ohm resistor
> > (would not fire with any higher ohm resistor) at 8.2mA to base

it

> > will fire relay using 5v supply. When tried to fire with para

port

> > only drew 4.2mA and would not fire 2222.
> >
> > Any Ideas what the para port is capable of?
> >
> > Have been reading all the replies and would like to thank all

for

> > help.
> >