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LED lightbulbs and X10 dimmer switches?

As an experiment, I ordered an LED bulb advertised on its web site as "compatible" with dimmer switches. As I sort of expected, "compatible" doesn't mean it actually changes luminosity - it just means it works :-). In practice, it comes on at some point and goes off at some point, and no dimming seems to be evident.

With the light bulb police gaining ground all over the world, someone must have figured out that there will be a market for replacement bulbs that still work with X10 dimmers.

Surely it would be possible to build a bulb that measures the duty cycle of the input AC and controls the brightness of the LEDs from it (possibly a bit more expensive than the already expensive LED bulbs, but what the heck, the switches are more expensive too)?

Anyone know of any LED bulbs that actually work well with X10 dimmers? Anyone monitoring this newsgroup for new product ideas? :-).

Reply to
Tom Horsley
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I'm surprised that LED bulbs act this way. They should respond to the change in duty cycle.

I've had no luck with fluorescents either. They won't start. I suspect it's because their load doesn't meet the 10mA thrystor hold current right at startup (but I really don't know).

Bob

Reply to
Bob

"compatible"

:-).

change

it's

I'm running X10 as well and I suggest that you easiest move is to include a load that the X10 wants to see in parallel with the fluorescent lamp. I do this in two rooms using a small 7 watt incandescent bulb in each room.

The other solution is to replace the triac within the X10 switch with a solid state relay though this eliminates dimming.

Reply to
Lord Garth

Many LED "lightbulbs" only draw current over some smallish portion of each half-cycle of AC, probably around and just ahead of the voltage peak.

Ones lacking filter/smoothing capacitors should do better but will still differ from incandescents by having "bottom" being higher, light output at "midpoint of dimming" being higher, and "visually effective midpoint of dimming range" being lower and a little close to the bottom. Ones with the filter/smoothing capacitors do worse in this area as well as draw current spikes that make RMS current draw well above ratio of watts to volts.

- Don Klipstein ( snipped-for-privacy@misty.com)

Reply to
Don Klipstein

The way I would design the led bulb replacement suitable for dimming, would be have some of the led's in the array be voltage switched in steps. As in as the line voltage is lowered, some of the led's switch off in the array. I have not seen one made like that, but as a home project maybe? How bright is the led lamp you have - how does it compare for you to the lamp you replaced?

Reply to
James Thompson

It's good to hear that the parallel load (min hold current) technique works. I was going to construct a male-to-female socket adapter with an integrated power resistor, but your solution is much simpler and it would probably satisfy U.L., too.

Bob

Reply to
Bob

It didn't replace anything - it was just an experiment, but it isn't very bright. The web page (in addition to talking about dimmer compatibility) also talked about "reading light", but any standard Mom would give you hell for trying to read in the light this thing produces :-).

On the other hand, there are LED bulbs that I'm sure are plenty bright, like this one (which I wasn't willing to buy merely as an experiment):

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Reply to
Tom Horsley

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