Anything you want to know about dimmers

Buzzing Problems

A lamp consists of fine coils of wire held in place by a series of supports. When the current flow abruptly changes the magnetism change can be stronger than when supplied with a simple sine wave. If the dimmer has inadequate suppression the filaments will vibrate against the support posts (this is called lamp singing). A good quality dimmer will filter the abrupt current changing waveform that cause buzzing. This is known as EMI reduction. Changing the lamp brand to a higher quality one may also help to reduce lamp sing.

The normal light dimmer you buy in your local hardware center is a simple analog based one. However, these dimmers tend to have poor suppression and accuracy. As component values vary over time, the zero-crossing becomes inaccurate resulting in increased electrical and audible noise. If you find that your lamps blow more often than they should, it might be time to change your dimmer! Good quality dimmers are operated digitally using sophisticated designs, these units generate less noise, are more reliable and can control different lamps (low voltage, halogen etc) makes like "FUTRONIX" work like this and are amongst the best available.

Building a simple dimmer circuit