Re: cable shielding and relays

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "mrpootoo <mrpootoo@y...>"
<mrpootoo@y...> wrote:

> Hi all,
> I am just trying to finish up my router/plasma project and there

are

> two things I can't seem to find any info on.
>
> 1. I'm using a shielded wire for my motor connections - do I ground
> that wire at the machine or at my controller box?
>
> 2. Does anyone have a source for a safe (to my equipment), simple

to

> make or premade relay setup for turning on spindles, etc.?
>
> Thanks a bunch,
> Chris Coleman

Hi Chris,

The simple way to turn on spindles is to use an electronicly
controlled relay or called and SSR for Solid State Relay.

Jameco has a variety. if you are using your parallel port you can
connect it directly as the input is opto-isolated.

Can't get much simplier than that.

your selection criteria is on/off signal. look for eight 5 volt or
3 to something over 5. I've seen 3 to 32 VDC and 6-12VDC. the 6 is
above the praallel port value so will not work.

Also, These are typically input signal at 5 volts (hi) to make
contact, lose the signal, lose the power thru the unit. that is what
you want. Normally OPEN is the term. Normally Closed is not what
you want as if your controller fails, you have things turning on.

In my searches, I find that these are usually rated for quite a few
amps. if you wanted multiple things to turn on, you could connect it
to a DPDT or 3PDT relay for multiple functions, light and coolant for
instance.

Dave