LED Tape acts up - with solution

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Theories abound, I see...

Just a note, I have installed this tape, these drivers and these dimmers in many locations previously, all without flicker. My sample size is large enough that I have a good deal of confidence in the products installed and in how they work together.

As far as LED tape being susceptible to RF, I know for a fact that an LED tape can be made to glow or even light at near full intensity from the driver and/or wiring being installed under the sink in close proximity (within 2-3 feet) to a disposal. You can make LED tape light up just by touching one of the solder pads with your finger in some cases. This suggests that it's relatively easy to introduce the few milliamps needed to cause interference.

Gar, you are making pretty concrete claims that this has to be a dimmer issue. How would you go about proving that, for instance using an oscilloscope or other test equipment?

As for the dimmer, you must use a dimmer rated for magnetic low voltage lighting with the GM drivers when specified. I generally use either the AYLV600P or a DVLV600P with the GM drivers, depending on whether the rest of the switches are toggle or decora style. A two wire or three wire dimmer will work, as long as it's rated for magnetic low voltage loads. I also have found the neutral equipped dimmers to be more stable in certain situations with other LED lights, but their price is certainly not negligible and often forces the added complication of working in a decora device to an all toggle setup.

I kind of wish I had had a neutral equipped MLV dimmer with me to try at the time, but I didn't and I really can't afford another 50 mile trip just to test it (I did test a three wire dimmer, but it wasn't rated for magnetic low voltage loads and also flickered). I also like the idea of testing one horizontal and one vertical tape, although that would have been considerably more time consuming to do because of the way the tape is connected to the wiring on the horizontal runs.
 
171201-2504 EST

PetrosA:

Gar, you are making pretty concrete claims that this has to be a dimmer issue. How would you go about proving that, for instance using an oscilloscope or other test equipment?
From what you have described your driver consists of a 60 Hz transformer, nominal 120 V to about 10 V, with a bridge rectifier from the approximate 10 to 12 V secondary to produce a DC output voltage that drives a nominal 12 V DC LED string.

Assuming the driver is only a transformer and bridge rectifier, then supply this from a Variac (if fed with a sine wave, then the output is a sine wave continuously variable from 0 to full voltage) and you will have no flicker other than 120 Hz ripple. No scope or meter required. There is nothing here to cause flicker.

To get any outside power into this circuit will require a transmitter with a lot of power output, possibly 100 W or more, and an antenna close by, possibly inches. Therefore, dimmer is the problem.

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171202-2428 EST

ELA:

Your Lutron reference provides a very good discussion.

But it in some respects the discussion really indicates that line voltage dimming low voltage LED strings is the wrong approach.

Whereas blkmagik21 in post #8 suggested a far better method. Why didn't Lutron mention this.

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171204-0923 EST

I picked up a Home Depot 12 V pulse width dimmer yesterday. Looks like one manufacturer makes these with different face plate labels. Home Depot is expensive compared to on-line.

This pulses at about 120 Hz (measured close to 8 mS). Range is about 3% to near 100% on time. But just quits near the 3% point. I would classify this as a design defect. This low pulse rate might be to reduce RFI.

Much better approach than using a line voltage regulator.

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