Triacs

Triacs, symmetrical thyristors

The triacs

Triacs, also called symmetrical thyristors or triacs (from English triac — triode for alternating current) are semiconductor elements from the group of thyristors. The triac is designed using a five-layer structure and has bidirectionally adjustable conductivity. It is used for commutation and regulation of variable loads at high voltage. Of utmost importance for automated processes in consumer and industrial electronics, as well as in automated manufacturing processes.

The five-layer structure with four junctions between them can be seen as a union of two thyristors. Both thyristors are unblocked by pulses of the control current Ia with the same polarity. Bidirectionality of triacs makes them widely applicable in non-contact AC regulators, for controlling low-power inductive loads, dimmable lighting fixtures, etc.

The majority of triacs are small in size and designed to be embedded in circuit boards by soldering, and surface SMD is mostly used for mounting.

Mounting

 

• SMD
• THT
• on radiator
• paneled