Editing TRIAC (section)

==Application==
[[File:Triac funktion.gif|thumb|right|Typical use as a dimmer]]
Low-power TRIACs are used in many applications such as [[electric light|light]] [[dimmer]]s, speed controls for [[electric fan]]s and other [[electric motor]]s, and in the modern computerized control circuits of many household [[Small appliance|small]] and [[major appliance]]s.

When mains voltage TRIACs are triggered by microcontrollers, [[optoisolator]]s are frequently used; for example [[optotriac]]s can be used to control the gate current. Alternatively, where safety allows and electrical isolation of the controller isn't necessary, one of the microcontroller's power rails may be connected to one of the mains supply. In these situations it is normal to connect the neutral terminal to the positive rail of the microcontroller's power supply, together with A1 of the triac, with A2 connected to the live. The TRIAC's gate can be connected through an opto-isolated transistor, and sometimes a resistor to the microcontroller, so that bringing the voltage down to the microcontroller's logic zero pulls enough current through the TRIAC's gate to trigger it. This ensures that the TRIAC is triggered in quadrants II and III and avoids quadrant IV where TRIACs are typically insensitive.<ref>[http://www.st.com/web/en/resource/technical/document/application_note/CD00003868.pdf triacs and microcontrollers - the easy connection]</ref>