Curve Tracer calibration complete, one verification waiting on a resistor

MORE CALIBRATION PROGRESS

The additional adjustments completed were:

  • step generator gain to 1V per step (revalidated)
  • high voltage range to 200V max (only got to 191 but that is within the +/- 5% spec)
  • mid voltage range to 70V max exactly 
  • low voltage range to 35V max exactly
  • DC mode voltages also 200, 70, 35
  • zero level of triangle waves set
  • gain of X amplifier to 1:1 with device output
  • Y channel offset to exactly ground level
  • step delay timing max
Verifications were done for:
  • high voltage indicator operation
  • Y amplifier 1/10 gain signal identical to 1:1 signal shape
  • current limiting accuracy
  • X-Y mode operation
  • good curves testing BJT device
  • step generator protection circuit both N and P modes
I learned that I need to add 1s persistence to my Tektronix digital scope when in XY mode otherwise the curve tracing creates an annoying flicker. With that, the instrument worked great. I put everything in the enclosure and carefully installed all the knobs. 


The remaining verification is to demonstrate that the unit can deliver its full 100ma of current to the device under test at the maximum 200V setting. The unit can drive up to 2A at the 35 and 70 volt levels, as much as 140W to the device being tested, but 200V operation has a max power of 20W it can deliver.

To accomplish this requires a 5W 2K ohm resistor which I didn't have on hand. When it arrives in a couple of days, I will perform this last verification and consider the project complete.  

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