Electric OU: Ainslie Demo Highlight 2.5: Probe Fiddling Test Attempt and Fail
Here the team responds to a question from a viewer, I think. The idea is to test the difference in scope readings between the two sides of the Current Sensing Resistor or “shunt” while the Q1 mosfet is ON and indisputably carrying current.
DISCLAIMER: The audio and video problems are AS ORIGINALLY STREAMED by the Donovan Martin-Rosemary Ainslie Team. This is just a clip, I am NOT RESPONSIBLE for their errors and bad presentations. They used a cellphone to present this important demonstration!
(EDIT: Please see S. Weir’s comment below where he explains his test request and his analysis of the result. He was more concerned with the Q2 behaviour for this test and it appears that the screen capture made at the end was suitable for his Q2 oscillation analysis. However it would have also been useful for the Q1 Figure 3 Smoking Gun analysis, had they only boosted the Gate drive slightly more to correspond with the drive indicated in Figure 3. Of course this discussion would be greatly facilitated if only we actually HAD those screen captures to analyze. The Donovan Martin team has not released them, though, and I doubt if they ever will.) End edit.
So a rational person might have the probe in the correct position, run the Gate voltage up to 12 volts, do a screen capture of the oscilloscope, move the probe to the other side of the resistor, do another screen capture, then move the probe back to the original position for a final capture, and turn the Gate signal back down so the mosfet doesn’t overheat. It actually takes me longer to type it in than it would take to perform the test.
Technically this is called an “A-B-A trial paradigm”. The point of the second “A” condtion is to make sure nothing else has changed in between the trials that would affect your data. Even better is A-B-A-B in some cases.
(EDIT: Performing the captures in this manner would have also given S.Weir the information he desired for Q2 and the oscillations. Enough data to satisfy us both, in just three captures, and it would have taken five minutes, maximum, for a cooperative and competent “team” to produce this data.) End edit.
But watch, and learn from the Genius NERDs. Fourteen more minutes of two thousand people’s time…. down the drain with no useful product at all. Not even a single usable capture: the one that was performed did not have the gate signal high enough to turn the transistor on.
At the end of this video, where Donny says that they are ready to start…. I cracked up.
They are further from a Fig 3 screen than they were when they started at the beginning of this video. Donny has no clue, and worse than that: he apparently has no clue that he has no clue. Can you say “Dunning-Kruger Effect”? Here are two examples of extreme cases of same: Rosemary Ainslie and Donovan Martin.
There doesn’t appear to be a “mismeasuretainment” category so I had to put this in “science and technology.” Sorry if you were expecting some science or technology, and got a bunch of grownup children playing with a five thousand dollar Etch-a-Sketch instead.