Noise from low voltage cans

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danickstr

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Does anyone know if noise from low voltage cans is a dimmer issue, a dirty power issue, or a bulb issue? A combination or none of the above?

I run into it all the time, and people ask what can they do, I know that it is often a magnetic low voltage tranny in the can, not sure if electronic would change anything.
 
danickstr said:
Does anyone know if noise from low voltage cans is a dimmer issue, a dirty power issue, or a bulb issue? A combination or none of the above?

I run into it all the time, and people ask what can they do, I know that it is often a magnetic low voltage tranny in the can, not sure if electronic would change anything.
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ActionDave said:
I only know what the tech support at Lutron told me, "Magnetic transformer gets a magnetic dimmer, electronic transformer gets a electronic dimmer. The lights will dim without a matching dimmer but you may have some issues."
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Exactly, I second wrong dimmer being used.
 
I have had large batches of defective transformers in recessed can lights. the manufacturer provided replacement parts but we had to replace 30 transformers in 4 inch cans. With no attic space this can be fun. you need small hands and you need to be able to work blind.
 
Larry is right. Take the dimmer out of the circuit first.

If you have recessed cans, the transformers should be magnetic so the dimmer should be magnetic.

Lamps could be the issue.
 
thanks for replies. I have now read an article from 2007 here on this illustrious forum about "filament singing" - interesting phenomenon. Some dimmers will produce a harmonic interference based on the frequency of the dimming by the solid state components, and the length/diameter of the filament.

So many hurdles to contemplate....
 
Wrong dimmer will usually be the culprit. In audio studios we used Variac's to dim.
 
I have had problems with magnetic LV tranies. I put in 26 in an Office and the rep guaranteed they wouldn't make noise. They did- we change bulbs dimmers, etc. The fix was to replace all the tranies with new ones that were electronic.
 
Reverse phase (used for many electronic transformers) dimmers work with both incandescent and electronic transformer and combination of the two, but you can't put magnetic low-voltage transformer on reverse-phase dimmer.

Rev. phase dimmer is even specified as needed just to power regular incandescent to reduce RF interference, but not to reduce acoustic noise.


You need to figure out where the buzzing is coming from. Using a standard dimmer, normal 100W light bulb is objectionably loud. A dual bulb halogen lamp is inaudible (halogen capsule encased in standard bulb).

If its a low voltage and its coming from your transformer, you may want to consider using a debuzzing coil and a dimmer with neutral connection(for proper functionality)
 
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