sine wave dimmers 1

[geekEE]

Are there any sine-wave dimmers that will be a replacement for those noisy triac-based dimmers? The load consists of incandescent lamps of maybe 1500-2000W (120VAC 60Hz). I would like to eliminate some electrical and audible noise for an audio listening room. I suppose I could use variable autotransformers, but I think they are probably too big to fit in a standard switch box.

Or are there any other solutions that I should be looking at?

Thanks in advance,
Glenn

 

[itsmoked]

Nope. Sorry. Incandescent dimmers are all phase-control not cycle control.
There are Variac auto-transformers that are made to dim incandescents but they are generally limited to theater applications. They're about 8" in diameter and 3" deep.

Your best bet now is probably getting the Cree LED bulbs which are dimmable. Their filaments won't "sing". And the current will be so low the dimmer itself probably won't buzz either.

Or go out-of-the-box and use completely separate "dim lighting" like indirect rope lights or something then just turn off the bright lights altogether.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[ScottyUK]

But many triac-based dimmers don't like the very low load presented by LEDs, so check first.

Aside - has anyone ever tried running the LED lamps from a DC supply equivalent to rectified mains? I wonder...

 

[VEBill]

There are brazillions of 12 Vdc LED lighting solutions, systems, equipment available (cheap on eBay) It would be up to you to determine if the existing wiring could be reused, or if this is a non-starter due to the wiring.

One might even install two parallel systems. Leave the existing bright system for non-listening periods, and a less powerful silent system.

A pure DC system offers the possibility of perfect silence, assuming that the inevitable switching power supply is installed elsewhere.

 

[OperaHouse]

While it won't fit in a wall electrical box, a buck transformer could be used to dim the lights. In reality you never need more than two dim positions.

 

[jmbelectrical]

I'll have to second itsmoked's advice. Replace your incandescents with Cree LED bulbs. The 40W equivalents (6.5W) can now be purchased for $10 (USD). And don't re-use your existing dimmer, as LED bulbs are known to have numerous compatibility issues with older dimmers. Pass & Seymour/Legrand and Leviton both now offer "universal" dimmer switches that are compatible with any type of lighting load.

 

[jimkirk]

Another vote for going to LEDs, you'll save lots of power.

But if you absolutely have to stick with incandescent lamps, check out "reverse phase control" or "trailing edge" dimmers. Instead of varying the turn on phase and hitting the filament with a large step in voltage, they turn on at the zero crossing and vary the turn-off phase, producing much less audible noise.