Re: coolant pump control questions

Mark:

This can be done with a simple transistor driver, which you can
build in an hour for a few bucks as another poster already
mentioned.

I've written an article on how to do it for folks with a limited
electronics background:

http://www.dakeng.com/relay.html

Good luck with your project!

Dave Kowalczyk
Everett WA

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "markpowerplus <mabw@b...>"
<mabw@b...> wrote:

>
>
> Yes , the problem I have is the control side of things, I don't

know

> the range of the PC . By "switching" on the coolant in the software

I

> get a 5 volt reading on pin 1 of the parallel port but it will not
> switch the relay which is a 5 volt 10 ma. When I connect the relay

to

> pin 1 and the other side to earth the volts drop off to almost zero

I

> am guessing here at saying there is not enough current? this is the
> smallest rated relay I could find (it is a reed relay) I could not
> find a solid state relay in 5 volts.
> help please!!!!!!!!
> thanks
> Mark