Does an automatic shutoff energy saver light switch exist?

Sure, my neighborhood bar has them in the restrooms-men's at least.

I've seen motion detector light switches at Lowes. I don't remember the price, though. You set them for a certain delay, and after so much non-movement, they shut off. What I'm looking for now is a humidity activated switch that automatically turns on the bathroom fan when it gets too steamy in there. :)

j

Bathroom fans with humidity switches are standard stock items.

Automatic (timer/pir) light switches are standard stock items.

I have PIR lighting on most of my stairs and hallways. They are supplemented by a number of push button (actually pneumatic) timer switches that I can operate with an elbow.

The one thing I very certainly do not want to do on the stairs is to try and find a light switch in the dark, or operate it when both hands are already full carrying something.

Nagging people to turn off hall and stairway lamps is one of life's pleasures that I would rather do without.

| The one thing I very certainly do not want to do on the stairs is to try | and find a light switch in the dark, or operate it when both hands are | already full carrying something.

Or try to figure out whether it is currently off pointing up and needs to be pushed down, or is currently off pointing down and needs to be pushed up. That's why I won't have 3-way switches on stairs or even in hallways.

| Nagging people to turn off hall and stairway lamps is one of life's | pleasures that I would rather do without.

That's definitely something I will be considering in a lot of places.

Those won't work properly with florescent lights.

Why not? Other than cycling more often, which hastens early end of life, they work fine. I have had a motion sensor on my garage lights for years.

It probably has line and neutral (return) in, rather than just line in and line out and uses a miniature relay to switch the load on/off with no dimming function.

The ones with just line in and line out and with a triac as the control element, rather than a relay, can be a problem with some loads.

If they cheaped out and used an SCR I can see the problem but even then I doubt an electronic ballast would even notice. You might get some flicker in the light since it would only be seeing a half wave. A Triac in saturation should just be "on". I have all sorts of stuff running on SSRs (PCs, TVs, audio amps) and IBM did it all the time. (where I got the SSRs)

I have seen a discussion about this that said if you are using a parisitic switch module (no neutral connection) you might not get enough current through a CFL when off to power the circuit.

I have a line voltage humidistat from Honeywell. It surface mounts on a wall box - air needs to get at the sensor.

It isn't the ballast that notices. It's the triac. The designer* relies on a minimum load current after the triac has been triggered, to hold the thing on until the next voltage zero crossing point. Loads like fluorescents often don't satisfy that design criteria.

*Who is working to a requirement. Tell him that a minimum load current cannot be guaranteed and he will keep sending firing pulses to the triac, so that, even if it tried to drop out, it would almost immediately be re-triggered. But this does add (a little) to the cost.

It isn't so much that some designers cheap out and use an SCR, it is that they cheap out and don't send a train of trigger pulses to the triac, but just one.