# LET device?



## Dave_H (Apr 1, 2021)

Has anyone heard of, or seen, an obscure device called Light Emitting Triac (LET)? I believe it was
an early attempt to combine power control with lighting in single device; possibly GE? It may have
been late 1980's to early 1990's.

Dave


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## PhotonWrangler (Apr 1, 2021)

There's such a thing as a light _activated_ triac, a sort of photoelectric latching relay, but I've never heard of an LET. Interesting.


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## Dave_H (Apr 2, 2021)

LET there be light! No such device! If so it would have had to be introduced on April 1st. 

GBGL! (Great Big Guffawing Laugh)

A friend who is a power engineer commented that almost anything will light up if you pass enough current through it.

This was inspired by an obscure but real device, the light-activated SCR (LASCR); SCR's being inherently light-sensitive. The small device I played with way back was packaged in a clear TO-92 with a concave lens formed into the rounded back, focusing on the die. Light-activated triac (LAT?) also makes sense.


Dave


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## Katherine Alicia (Apr 2, 2021)

Dave_H said:


> A friend who is a power engineer commented that almost anything will light up if you pass enough current through it.









Gotta love that magic Smoke!


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## PhotonWrangler (Apr 2, 2021)

Lol. There is the NED (Noise Emitting Diode). It only works once though. Very briefly.


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## Dave_H (Apr 4, 2021)

I was thinking to include reference to the predecessor of the SCR, the Germanium Controlled Rectifier (GCR)
but not being lighting-related it would have been OT and would raise suspicion...

Dave


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