I have been using a bog-standard dimmer switch (fitted about 20 years ago) with a 10W dimmable LED lamp without any particular problems. (Although at certain settings it does start to flicker).
I want to fit some of the other rooms with dimmer switches so have picked up another couple of bog-standard dimmers. But they come with dire warnings about minimum load blah blah.
Should I return these and get (vastly more expensive) LED-compatible dimmers? Is there a difference in running cost?
Dimmers used with RC ballst LEDs will kill the led lamps quickly. Used with electronic ballast LEDs there won't be a problem.
Effective way to see if a dimmer misbehaves with a small load is try it. Its certainly not a risk situation.
NT
I'm guessing then that a "dimmable LED" is one with an electronic ballast?
Yup, RC ballast LEDs fry in a minute on a standard dimmmer.
NT
No difference in running costs.
The older dimmers are "leading edge" - the traditional triac-diac simple dimmers.
The newer "LED friendly" are "trailing edge".
Now - IME many dimmable LEDs and CFLs work OK with leading edge dimmers
- but you can sometimes get one LED (even from the same range) that flickers like mad. Sometimes this goes away if you have one incandescent lamp in to prove a bit of load (this is more of a "dimmer does not like tiny loads" problem.
Other failure scenarios include the LED pulsing randomly once ina few minutes as the dimmer (usually electronic push button types) lets but a very small current to power itself and this charges up the capacitor in the LED PSU.
Other folks say that the wrong combo can shorten the life of the LED - I have no evidence on that either way.
Thanks for the info.
I've put one in now; it seems to flicker a bit when turned up to maximum but this goes away if I back it off a tadge.
Yes - I've had that once - rather counter intuitive (at least from my knowledge of electronics!).
I expect problems at the max-dim end, but not at the top.
The problem with a lot of dimmers is that at low loads they do not have a stable performance. This used to affect ordinary bulbs as well. Its a little like the old problem of volume controls being used in the first five percent of their range, after a while they go crackly there. I don't think you will damage things, just pot luck as to how they react on low wattage loads. However, the leds seem to need to be the ones ok with dimmers as presumably they contain switch mode power supplies of some kind and not all will be able to work on the waveform presented by certain dimmers. Brian
Surely putting in filament lamps rather defeats the object?
Brian
I've had to replace a dimmer for a strip of 3 LEDs in our kitchen because after a time it only worked over part of the range, and the working range kept reducing.
Similarly with a single 60W halogen.
Seems that particular dimmer didn't like working at the lower end of the rating because the dimmers handling 2 * 60W and 3 * 60W have worked fine, never missed a beat.
The expensive replacements seem to be lasting well.
Cheers
Dave R
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.