Electric OU: Supplement: Driving a MOSFET by LOWERING SOURCE VOLTAGE Part 3

Please refer to Parts 1 and 2 for the setup and schematic used.
(The actual schematic actually used at this point in time, I actually mean.)

Here I’ve made two simple changes in the hardware: I’ve used 2 ea. 12 v batteries in series for the power supply, and I’ve changed the mosfet for one of Tar Baby’s Q2s, including its cable and connector. I had to take the distal shell off and just stick the pins into the board’s socket but it works.

First I show that the IRFPG50 behaves just like the IRFP450 that was in there before, except with a higher drain-source resistance when on.

Then I ramp up the frequency until the bulb appears constantly on.

Then I show the difference between changing amplitude with the amplitude knob, and changing offset with the offset knob. The difference is dramatic.

Then at the end, I actually am able to produce some oscillation. I was gonna save that for the next video but since it popped up so nicely… there it is. I was afraid I might have to add a capacitor but it looks like the lead inductance is sufficient.

I know I said that the “next” video would be adding another transistor, but maybe I need to put the CVR in first, to prove oscillations more rigorously. Stay tuned, there will be more.

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