Inside a TO-3 Transistor case

[mixos]

Ever wondered how a TO-3 transistor is from inside view? See below:

[electrodoc]

If you use a faulty transistor and whip the top off then connect a volt meter across the base and collector whilst pointing the transistor at the sun it's a solar cell !!

8)

[MP]

Hmmm...That's interesting. What voltage and current have you measured from one? There's not much surface space there.

MP

[electrodoc]

it was a few years ago when i was begining in electronics i got approx .25 of a volt and i didn't take a current measurement im afraid. a guy who was known to be eccentric told me of this phenomenon so i tried it and low and behold there was a voltage there.

[MP]

It makes sense, since light absorption is a characteristic of silicon. I was just surprised that you could have enough surface space to get such a reading. Thanks for sharing that!

MP

[Guest]

Are there specific transistors which can give more output voltage.

[steven]

:)electrodoc i to have herd about this , takeing the top off a transister to use like a solar cell

[surajbarkale]

I used the SL100 with it's top chopped off as a phototransistor (2N3055 was too heavy for my hacksaw then ;)). It gave good response indeed. But beware you have to cover it with some material to keep the dust off else it will die slowly. ;D

[Dido]

I have heard about this but I never thought It was true.
Do the Solar Cells have the same working structure ???

[audioguru]

Photodiodes can also be used as current generators for fast response. You can identify this circuit when the photodiode is directly connected to the inverting input of an opamp that also has a feedback resistor.
Usually, photodiodes are reversed-biased with a resistor, and light (or IR energy) causes them to leak some current. Since the leakage current is very small, the resistor has a high value and the voltage across it is sensed with a non-inverting (high impedance) opamp.