At 10:43 AM 5/27/04, you wrote:
>On Thu, May 27, 2004 at 12:52:41PM -0400, Bob Ammerman wrote:
> > The neutral is not available a good percentage of the time at a standard
> > single pole switch in a home. In many cases a two-wire (plus safety ground)
> > cable brings hot to the switch and switched-hot back to the load.
>
>I don't profess to be an electrician and I don't have a lot of experience.  I
>guess it shows. Every box I have in my 30+ YO home has hot, neutral and
>safety ground (SG). I'm just trying to envision a wiring diagram where only
>hot and switched hot (SH) are available in a box. I guess I can see it: hot,
>neutral, and SG come into the light fixture. A separate wire with hot and
>SH goes to the switch box. So there's three wires, but no neutral. BTW
>how is such a line (especially the white wire) supposed to be marked?

That is the case in many switched lighting outlets.
Hot and neutral in the ceiling box, hot going to the switch box and switch
leg returning to the lamp.

Intermatic makes digital lamp time switches that you can program with a
half dozen on/off times.  It gets it's power by putting part of the circuit
in series with the incandescent lamp while off.  While the lamp is on is
another story.  I happen to have a burnt out unit in my hands (don't know
why I never threw it away).

It has 15 resistors, six caps of varying sizes, 9 diodes, five transistors,
one triac and a toroidal inductor to support the display.
If I get some time, I can see about throwing together a rough schematic of
at least the power section so you can see the "magic"

Then again, one could always pick up one of these at your local home
improvement place and modify to meet your needs.


>BTW am I right about having to leak current through the load? And what the
>heck do you do if the load isn't resistive?

The intermatic switch has a stamp on the back "Incandescent Loads Only"

Scott

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