Re: Transistor VCBO test setup

emtron2@xxxxxxxxxxx wrote:
I used to test transistors VCBO using a high voltage transformer,a
varic, a limiting resistor, a diode and a current sampling resistor.
An oscilloscope in XY mode was used, with the X calibrated in peak
volts and the Y to detect the breakdown current.
I don't remember the criteria to set the value of the limiting
resistor. I am testing 100 W TO3 Ge transistors with 100 K as limiting
res.
and the knee is not well defined (rounded).
Perhaps that is normal for Ge .
Will appreciate any help.
Ed

It has been ages since i have done that with any transistor, and ages since i had any "flower power" (Ge) transistors to mess with (gave them all to a museum for use as replacements).
But i do remember that they were rather leaky compared to any "sand power" (Si) transistors - so i am not surprised about that rounded quality.
In fact, i would be surprised if it was sharp.
.

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