Electrical light/transformer problem...

[Baronz]

So I've got this light that uses low voltage halogen lights, and it has a transformer on the light thing that converts AC to the low voltage.

Anyways it works fine, with a regular on/off switch.

But I installed a dimmer, so now the light fixture hums quite loud whenever its around 50% lit, hums a little at 100% and a little less the lower you go. And it's pretty loud.

So apparently (googled problem) I need a type of dimmer with a noise blocking sorta thing, "inductive"? to stop it from humming. I think those ceiling fan ones have noise reduction things do it doesn't do this, but i could be wrong.

Any ideas?

 

[FoBoT]

do what Mark R says down below 4-5 posts

 

[Mark R]

You need a 'dimmable' transformer, and a 'low voltage lighting' dimmer.

Conventional dimmers/transformers will make lots of noise, get hot, and lots of other undersirable things.

 

[flot]

Er, unless your low voltage light specifically states that it can/should be used with a dimmer, I think you're doing very bad things to it by trying to use one.

 

[rival]

im pretty sure you need a special dimmer, typical household dimmer switches only work with incadescent lightbulbs

sounds like the dimmer should be installed after the transformer, the transformer would require its full normal voltage to operate properly i think

 

[Mark R]

You need a special transformer and a special dimmer.

You can't put the dimmer after the transformer - typical mains dimmers need about 30V to trigger the circuits, and they wouldn't be able to take the current - 20A would fry it.

Conventional dimmers are 'leading edge' phase angle control switches - a transformer connected to that would buzz like mad, and you may find that it is difficult to control the brightness, because the inductive transformer upsets the dimmer's timing.

Dimmable transformers are not actually transformers, but SMPS (rather like a PC PSU) but they produce unfiltered high-frequency AC - they are also capacitative, rather than inductive.

A conventional dimmer can't power a capacitative load, the dimmer's main transistor will blow. That's why you need a 'trailing edge' phase angle control dimmer which is designed to power a capacitative load