We at all times get pleasure from movies from [w2aew]. His current entry appears at vertical or VFETs, that are, as he places it, a JFET that thinks it’s a triode. He clearly explains how the transistor works as a conductor except you bias the gate to type a depletion zone.
The transistors have a brief channel, which implies they conduct fairly effectively. The low gate resistance and capacitance imply the units may also swap in a short time. These units have been as soon as in vogue for audio purposes. Nevertheless, they’d fallen out of favor till lately. The reason being that they work fairly effectively in switching energy provides.
How good is the on resistance? So good that his meter reported the probes have been shorted as a substitute of measuring the resistance. Fairly good. We’ve seen these VFET transistors used as switches to drive magnetic discipline coils a few years in the past they usually changed way more complicated circuitry.
The curve tracer within the video is a stupendous instrument of its personal. The digital shows give it a excessive tech but retro look. A curve tracer, in the event you haven’t used one, plots stepped voltages in opposition to present flowing, and may be very helpful for analyzing semiconductor units. Whereas not as fancy, it’s potential to make one to hook up with a scope fairly simply.
We’re fairly certain that it’s a Tektronix 576. We watched a restore of an analogous unit, the 577, in the event you’d prefer to see some (in all probability) comparable insides.
