It would be more impressive if he knew what he was talking about. He constantly talks about using transformers for voltage reduction. This is DC guys! You use DC to DC converters, a complex analog circuit, not transformers!
Also Jordan of The Limiting Factor showed that Tesla’s side cooling was better than bottom cooling since you have a bigger contact patch area.
Um. I know DC-DC converters; DC-DC converters are friends of mine.
The isolated types do their step-up/step-down business by taking DC current and, using switching transistors, rapidly run current back and forth through the primary of a
transformer; the secondary of said transformer has an AC waveform that gets rectified with more switching transistors, and then gets filtered with caps or chokes. This is all done at the highest frequency possible, typically in the 100’s of kHz to MHz. The effects of doing all this at high frequencies shrinks the size of the transformers hugely. A 60 Hz transformer doing 500W might weigh a couple-5 lbs; a DC-DC at that power level might weigh a couple ounces, max, and would consist of some ferrites clamped over a circuit board with the primary/secondary windings simply being traces on the circuit board. 95%+ efficiencies, typical.
The non-isolated types (boost, buck, or boost-buck) have similar efficiencies but, rather than having a transformer, have ferritic inductors for energy storage. These aren’t transformers, per se, but from the outside they look like them. And still use switching transistors (and sometimes diodes, or switching transistors rigged to act like diodes) to get the energy through the inductors.
Main point, though: the voltage/current transformation from low V/high current to high V/low current or vice versa is still using things that sure as heck are transformers or look like them. So I’d give him a pass on that one.
Mind you, it’s possible to build power supplies that go up or down in voltage with nothing but transistors, diodes, and capacitors, foregoing the inductors, but nobody I’m aware of does it that way except for very compact, low power applications. Like RS-232 differential drivers that want to put out +/-12 V starting from 3.3V, but it’s all low current, low power.