Re: [CAD_CAM_EDM_DRO] Parallel port relay blues

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


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.
>