A very simple dimmer circuit with only the essentials. (In this circuit, the values are given for a BT138 at 220V AC, for 115V AC you may have to experiment with the values.)
|Simple lamp Dimmer 220V Circuit|
- D1 = diac (silicon bidirectional trigger device) BR100, ER900 or similar
- Tr1 = triac BT138, TIC226...
- This circuit is potentially dangerous! this is nothing for beginners!
R1 can vary from one triac to another, put a 220KΩ trimmer in its place and adjust. After adjustment, measure the result and replace the trimmer with an ordinary resistor of the same value.
Circuit From: http://home.scarlet.be/