transistor as a rectifier

Sparky49

Joined Jul 16, 2011
833
Hmmm, I assuming you mean a Silicon Controlled Rectifier?

I've drawn it out on the left hand side of the attachment, it requires one NPN and one PNP transistor. I'll let you figure out how it works, but if you can't figure it out, just ask.

Why not use a dedicated SCR? Like on the right?

Sparky
 

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SgtWookie

Joined Jul 17, 2007
22,210
Actually, an NPN transistor can be thought of as two diodes that are connected at the anodes; the junction is the base.
A PNP transistor can be thought of as two diodes that are connected at the cathodes; the junction is the base.

They are not typically used as dual diodes, as the emitter-base junction typically has a low reverse voltage breakdown, and the doping is different on the collector than on the emitter; using actual diodes is much better. However, as an experiment for a hobbyist, they can be used as such for low-power circuits.

It can also be a useful salvage technique; if an emitter or collector pin gets broken off, you can still use the base and remaining junction as a low voltage diode.
 
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