Photo sensor with led?

Hi. Can I use a photo sensor with led accent lighting? I purchased the GE gelcor 18 inch light string for under the cabinet. It uses a 110 AC to 4.5 volt DC transformer. Will the transformer get damaged if the sensor is in the flicker stage? Thanks in advance, long time reader, but still a newbie. Ken.

This is an interesting question (that's a nice way of saying that I'm not sure of the answer yet!) /ubbthreads/images/graemlins/blush.gif

If the output of the photosensor is the type that chops the AC sinewave, this might allow dangerous spikes to travel through the low voltage power supply and damage it and/or the LEDs. However if the photosensor is passing the full AC sinewave to the load, I think it would be somewhat safer. I would recommend trying it with a less expensive AC-powered LED first though.

While I don't know what a GE gelcor (or for that matter what 'flicker mode') is, I've been using a (home made) photo sensor circuit to turn LEDs on an off automatically for some time.

I'm just using a MOSFET in series with the minus lead with a photo resistor and fixed resistor driving the gate (as suggested by DRS2000). No problems as of yet in several systems. So yes, it's possible....

Doug Owen

Flicker mode I think is when a photocell first notices the dark and turns on. If you happened to have an older model of an automatic nightlight, you may see it flicker just before it gets to full brightness as it gets dark. Thats why some automatic outdoor fixtures can't use flourscent bulbs.

Anyway, if your photocell circuit includes some sort of relay, you shouldn't have a problem with flicker. Just click and instant full power.

Thank you for the responses. Working so far so good. Just to clarify, the led I have is Ge Gelcore 18" flexible under cabinet light bought at Kmart for $24.88. It has 5 leds with 2 sided tape for mounting. Your knowledge is greatly apprecciated.