Re: Repeatability of Home switches

Hi Mgaber,

any circuit needs to have a plus or positive and a minus or ground.

When you think home power wiring, if you bring power into your light
bulb, then after your bulb, you have the switch, it works. if you
put the switch before the bulb, it works too. one feeds power into
the bulb, the other drains it away.

sink or source ? for 99% of us home-switch, end-switch, zero-switch
guys, that does not matter.

You may be better getting a 'switch' and not a bag full of components
to roll your own, that way the circuit is not important, just your
field connnections.

There is also the electrical touch probe you can use for a home
switch. it takes almost 60 volts to jump a 0.001 inch gap so your 12
volt switch would offer a good resolution. chips and dust would
present a problem.

just how accurate do you need to be ?





--- In CAD_CAM_EDM_DRO@yahoogroups.com, "mrgamber" <mgamber@c...>
wrote:

> Thanks, but still confused...
>
> If I am trying to uses this type of a switch as if it were a normal
> SPDT switch, will it work?
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, JanRwl@A... wrote:
> > In a message dated 4/2/2003 7:46:42 PM Central Standard Time,
> > mgamber@c... writes:
> >
> > >
> > > The output on the switch is confusing, does sink mean that it

is

> > > coupling the supply voltage to the output? Or is it contact
> closure
> > > like a normal switch
> >
> > mgamber: "Sink" means the part has a solid-state output
> that "connects" the
> > output to GROUND or (-). "Source" means it connects the output

to

> +, usually
> > +5 VDC.
> >
> > Generally, "sink" is done with an NPN junction (transistor) which
> has its
> > emitter connected to (-) ground, and the collector is tied
> to "output".
> > "Source" is done various ways, but think of that as basically
> the "same, only
> > reverse-polarity" for "sketching purposes".
> >
> > These two words, "sink" and "source" are used to express what
> semiconductor
> > junctions handling the output of an IC (etc.) are doing, but you
> might think
> > of a SPDT relay, the "wiper" being "output", and the other two
> contacts tied
> > to +ve and -ve. Then, as the relay is operated, it
> either "sources" or
> > "sinks". This is not the kind of explanation that makes silicon
> wizards
> > gleeful, but it is OK for beginners!
> >
> > Jan Rowland, Ignernt ol' Troll
> >
> >
> >
> > [Non-text portions of this message have been removed]