Author Topic: Transistor Configuration?  (Read 1254 times)

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Offline rexxar

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Transistor Configuration?
« on: May 31, 2013, 05:59:39 am »
I'm trying to fix my old analog oscilloscope, and I noticed a weird configuration of transistors. I'll attach a little schematic I drew of it.

Apologies if I've got the symbols wrong, but it's two NPNs attached to a JFET. I didn't know if there was a proper symbol for a pin that isn't connected, but the collector of A and the emitter of B aren't connected to anything. In fact, they're cut off right at the base of the package. (This is in the vertical amplification stage, and that's main input JFET, if that matters any.)

What is this configuration doing, and how does it work with those pins cut off? This is probably a dumb question, but I've never seen anything like it before. ???
 

Offline carbon dude oxide

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Re: Transistor Configuration?
« Reply #1 on: May 31, 2013, 06:53:33 am »
Picture?
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Everything Should Be Made as Simple as Possible, But Not Simpler
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Offline rexxar

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Re: Transistor Configuration?
« Reply #2 on: May 31, 2013, 07:11:04 am »
 

Offline sorin

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Re: Transistor Configuration?
« Reply #3 on: May 31, 2013, 07:35:30 am »
this  are FET-s and are used as a Diode, presumably for input protection
 


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