Touch Switch Controller for LEDs

[Southern Man]

I installed these: http://www.touchandglow.com/ProductD...Show=TechSpecs
to turn on-off the transformers for low voltage LED under cabinet lights. The transformers draw about 7watts. The problem is that the lights more often than not "flicker". I have three of these switches, two have one transformer connected and the third has two.

1. When I plug the transformers into a regular outlet there is no flickering.
2. Sometimes the lights are fine and the flickering starts a few minutes or hours later.
3. Two transformers on one switch behave identically.
4. Once the flickering starts it doesn't stop and sometimes seems to get worse.
5. If i turn the transformers of then on, or turn the touch control off then on, sometimes I can make the flickering stop. The longer I wait the better the chance of this happening.
6. If I connect a 40W incandescent lamp to the same circuit and turn it on, the flickering always stops, then starts up again when I turn the 40W lamp off.

My theory is that the wattage draw is too low to turn the internal touch control relay (for lack of specific terms for these things) fully on.

Any clues on how to fix this?

These are the lights I ended up using here: http://www.terrylove.com/forums/showthread.php?t=23456

[jadnashua]

Electronic switches often have both a minimum and maximum wattage requirement...how much do the things draw when on? Is that the 7W, or is that standby losses? Most electronic switches I've seen want at least 25W. The requirements should be (maybe burried) in the spec sheet of the switch. Nothing you can do about it unless you increase the load or change the switch.

[Southern Man]

The transformers use about 7W each when on. The spec sheet is what I linked to and is is pitiful and doesn't say a minimum.

They make a different unit for use with fluorescent bulbs. Maybe that would work better?

[Bill Arden]

They make a different unit for use with fluorescent bulbs. Maybe that would work better?

Yes. Most likely.

Most electronic switches aren't designed to handle transformers.

Given the really low inductive load there is a problem in the way the circuit triggers the Triac that is in the touch switch.

The X-10 switches I have use latching relays on the output and have worked great for many years.

[Southern Man]

Thanks Bill I'll try the modules for the Fluorescents. I think they have them at Big Box for cheap.

I've used X-10s for years and they give a nice solid click when they turn on. I've never had a problem with them either, except for a one touch tone controller that went bad. I use them to turn up-down heat and turn on-off water and hot water at my cabin. If I have to go with something like that though I just blew my budget out and have a bunch of wiring to do. Instead I'd just go with a manual switch drilled onto the receptacle plate.

[jadnashua]

I don't think 14W is enough for a typical touch switch to stay on properly...as I said, most I've seen require at least 25W, and some 40W to work properly. If the touch switch has dimming, it must be designed for a transformer or electronic transformer or you'll get unstability. A good dimmer for low-voltage transformer is not cheap.

[Southern Man]

The ones that I installed say they are good for incandescent and xenon. I figured that would work for LED. The ones for florescents are $7 each and I thing Slowes has them so its worth trying.

If it doesn't maybe I'll wire in a relay?

[Bill Arden]

The relays coil would be inductive as well.

[Southern Man]

I replaced the switches for ones for florescents and they work fine now. Problem solved.