# buzzing dimmers



## 480sparky (Sep 20, 2007)

Sure it wasn't the bulbs humming?


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## MDShunk (Jan 7, 2007)

Lutron actually has a technical note on their website that talks about "luck of the draw" with certain lamp filaments vibrating just the right way when dimmed. The dimmer actually "chops" the voltage really quick going to the lamp, and this can make certain filaments sing or buzz. The cure has always been to swap the lamps for a different brand or different style. Lutron has a little gizmo that you can wire into the dimmer and stick it in the back of the box called a "debuzzing coil" that works well too.

http://www.lutron.com/product_technical/FAQ.asp#OLE_LINK12


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## Bkessler (Feb 14, 2007)

Thanks md I knew you would know? Just like that one a couple of years ago about the fluorescent lights that would not turn on until I touched them with my finger. No ground on electronic ballast.


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## k2x (May 20, 2008)

Bkessler said:


> Thanks md I knew you would know? Just like that one a couple of years ago about the fluorescent lights that would not turn on until I touched them with my finger. No ground on electronic ballast.


That would have to be one cheap a$$ Chinese ballast. Or it might be the altitude here.


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## 480sparky (Sep 20, 2007)

The buzzing is caused by vibration of the filaments.

Changing to a rough-service / ceiling fan / appliance / garage-door opener bulb can solve the buzzing bulb problem. They have more physical supports for the filament than standard bulbs do.

Edit to add:

Normal sine wave:











Dimmed sine wave:


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## randomkiller (Sep 28, 2007)

Bkessler said:


> On a side note any one ever been dumbfounded by changing over a t stat?


 
Nope, have had some old heat pumps that had thermostats in the outside unit that ran in series with the indoor thermostat to bring on rack heat and that type of thing. Plan out the sequence of operation you have and replacing is easy.


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## 480sparky (Sep 20, 2007)

Bkessler said:


> .....On a side note any one ever been dumbfounded by changing over a t stat?


No, but keep in mind stats are nothing more than a control circuit.


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