Kapanadze Cousin - DALLY FREE ENERGY

[TinselKoala]

Me too!
It even got to the point that I avoid products by manufacturers that do that, and encourage others to do the same.

The problem there is that HP/Agilent and Tektronix are perhaps the two manufacturers that have the best equipment! And there are lots of them available on the surplus market.
The cross-references .99 lists are extremely useful, thanks. Still, it can be difficult to match some ancient transistor type. Fortunately these are seldom as critical as you might think.

[verpies]

1 ohm and 70V, with 40V we just are at the starting point of the bend in the trace.

On this scopeshot:
The slope of the trace before the knee is 600ns/400mA, this yields inductance of 105μH (should be 173μH) but it's close enough.
The slope of the trace before the knee is 60ns/400mA ,  this yields inductance of 1050nH (should be 50μH) so it is not complete saturation.

Notice that the ratio of saturated to non-saturated inductances (and current trace slopes) is approximately 1:10 on this scopeshot , however on this scopeshot this ratio is 1:26, so this is just a matter of insufficient voltage.

Of course, the non-rectangular switching characteristics of the BJT and the large resistance of the CSR, all play a role in slowing down the saturation and distorting these current traces.

[itsu]

Of course, the non-rectangular switching characteristics of the BJT and the large resistance of the CSR, all play a role in slowing down the saturation and distorting these current traces.

Ok, i wil redo this testing with a 0.1 Ohm resistor so we can see the difference.   

Regards Itsu

[verpies]

Ok, i wil redo this testing with a 0.1 Ohm resistor so we can see the difference.   

You can drive the KT926A BJT with the output of the UCC27511 Driver, if you want it to turn ON more.
Just make sure that the resistors, between the UCC27511 Driver and the base of the KT926A transistor, have resistance more than 5Ω, because the KT926A transistor has 7A base current limit and the UCC27511 driver has 4A current limit.
Even if the supply voltage of the driver (+V₁) is 20V,  then a > 5Ω resistance will keep the base current below 4A.

[TinselKoala]

re the scopeshots:

Not all the critical information is contained in the "numbers in boxes" of the DSO's screen.

To make it easier to interpret the graphical display, it would be nice if certain conventions were respected. For example, the channel baseline indicator (the little "1" in a red polygon at the left border of the screen) should be precisely aligned with one of the screen's graticule or gridlines, unless there is some compelling reason for it not to be. This makes it a lot easier to read off voltages from the displayed waveform at arbitrary time points. This is normally controlled by the "vertical position" and/or trace offset control.
Also please make sure that the channel volts per division, and time per division settings are indicated somewhere on screen or in the accompanying text. AC or DC coupled, and probe attenuation, are also needed bits of info.
The DSO scope also shows the trigger points in voltage and time, along the right and top edges of the display. It can be helpful if the "time" or trigger delay or holdoff setting is used to position the trigger point at a horizontal grid line. (ETA: I mean a "time" gridline, which goes vertically, but indicates a time on the horizontal scale.)

Thanks for posting the scopeshots. Keep up the good work!