Anything you want to know about dimmers

Dimmer Types

Older lighting controls used either resistors or large variable transformers called auto-transformers, These units had hand wheels mounted on top that needed to be turned in order to adjust the level of output. Needless to say these devices were very inefficient, large and expensive. Modern Triac or Tyristor based dimmers are either ON or OFF and hence dissipate very little heat. A typical voltage drop from these units when the power is transferred to the load is only a few volts with most of this being lost through the electrical noise suppression part of the circuit. The power devices have 3 connections a) Power in b) Power out c) Gate. The units conduct when a low power control signal is provided to the gate.

Radio frequency interferance