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7.7: Optothyristors

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    Like bipolar transistors, SCRs and TRIACs are also manufactured as light-sensitive devices, the action of impinging light replacing the function of triggering voltage.

    Optically-controlled SCRs are often known by the acronym LASCR, or Light Activated SCR. Its symbol, not surprisingly, looks like Figure below.


    Light activated SCR

    Optically-controlled TRIACs don’t receive the honor of having their own acronym, but instead are humbly known as opto-TRIACs. Their schematic symbol is shown in Figure below.



    Optothyristors (a general term for either the LASCR or the opto-TRIAC) are commonly found inside sealed “optoisolator” modules.

    7.7: Optothyristors is shared under a GNU Free Documentation License 1.3 license and was authored, remixed, and/or curated by Tony R. Kuphaldt via source content that was edited to conform to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.