Dimmer noise


When I use a dimmer to dim a light, it makes a light buzzing noise. Why does it make a noise?
samuellaudio
Virtually all dimmers are build around SCRs and Triacs and what they do, in effect, is turn the switch on and off really, really fast. Since conventional incandescent lights have a filament that doesn't respond that fast, the filament sort of averages the actual power its getting.

But, some other lights, like flourescents and halogens, don't like being switched on and off like that. I had a set of LV halogens on a dimmer in my dining room that made a huge racket when the dimmer was used. I replaced that dimmer with one meant to control halogens, and its been fine.

But, be aware that switching things on and off like that really fast really messes with the AC in your house. Most audiofools won't have a dimmer in the same circuit (even the same house) as a decent stereo. While newer dimmers may control noise coming from the switch somewhat, just be aware they are still (unless things have undergone some radical redesign I wasn't aware of) going to create ugly noise on your AC lines. You will hear that on your stereo.

Besides, dimmers don't work well with compact flourescents. You have changed to cheaper, more eco-friendly CFLs, right?
Try to avoid dimmers - nasty noise generators - also avoid energy saving lamps and fluorecents...

DV
Edesilva...When I said that the new dimmers which I have bought are quiet I meant with respect to buzz on audio equipment. They must have done something to avoid noise getting on to the power lines.

Halogens are just a different kind of incandescent and there is no noise problem. The problem with using a dimmer with them is that they don't get really hot, which is what a halogen must do to burn off deposits that dim their light.

Some compact flourescents can be used with regular dimmers. However, they won't start with reduced voltage, so you need to turn the brightness up for a second when you turn them down. Once they are lit they dim just fine.

The eco-friendly bit really bugs me. They talk about the energy that is "wasted" making heat. But in my part of the country we need heat most of the year, at least at night when lights are on. If the light bulbs don't make heat my oil burner needs to run longer. They are only eco-friendly when your air conditioner is running.
I have a ton of dimmers in my house and am also obsesed with clean power.

I am a lighting guru and have several recessed lights and such throughout the house and was not going to change my lifestyle of nicely dimmed lights opposed to overly uncomfortable bright lights for an audio system-I found a way for them to exsist together.

One night I did an experiment to see if I could hear the effects of the dimmers on my system. In my home theater there are 11 seperate light throughout the room that are on a two way electronic dimmers. From my sitting spot I can turn on and off all the lights while still sitting in my seat. While the music was on I turned on and off the dimmers. Wow, what a difference. When all the lights where turned on with the dimmer it was like it took life out of the system...chocked it. It was very noticable.

Now, the dimmers don't effect the sound at all. I have bought so many parralel type conditioners that the dimmers dont effect things anymore. I think theres over forty different types ranging from noise harvestors, b86's to enacom ac cleaners and quantum . I have 2 richard grays and audioprism foundation 2 which are also paralel cleaners by themselfs which serve just to plug all these in. I have a BPT sig 3.5 for my source. I understand many don't and won't spend that kind of money, but my lighting in my house is too important for an audio system to dictate an important part of house design.

Another thing you can do thats free that will help with dimmers. In the circuit breaker box there are two hots that come into the house. My system is on one of the hot legs, and all the circuits with dimmers are on the other hot leg. With the ps noise harvester blinking in my systems circuit, I tried a dimmer that was turned on and put it on my systems hot and the other hot opposite the system. The noise harvesters showed that the dimmers on the other hot gave less blinking to it.
When you dim the lights the filament start to vibrate,causing the noise. try a GE ConstantColor lamp.