Re: [CAD_CAM_EDM_DRO] Re: spindle start and stop

> Will there be enough voltage in the parallel port to operate your
> recommended relay? I seem to remember that that the max. voltage from
> the port is 3 volts and the minimum req for the relay is also 3 volts.
> Would there be a problem regarding safety?
> Thanks, Terry

The parallel port is a TTL device and as such it should produce 5V high. I
have used solid state relays (SSR's) up to 30A with no problem. However,
some parallel ports may not source enough current to drive the relay. If
you have this problem the easiest solution is to get a different parallel
port card. It's not likely a problem.

SSR's are probably safer than mechanical relays in that they don't have
points to stick.

Doug