Drain Caps Fast On Power Loss - Depletion JFET Switch Better Than Bleeder Resistors - Simply Put

Sometimes you need capacitors to drain when you remove the power (like unplugging or removing batteries), either for safety (use bleeder resistors) or because the device is designed so that the capacitors are expected to be empty on bootup. Bleeder resistors aren't great because they are slow, meaning you have to leave it unpowered for an extended period to let the capacitors discharge, but you can instead use a depletion transistor such as a JFET (which acts as a normally closed (NC) switch so you can have a fast drain path that gets blocked while the device is powered.
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[@untasnaz]

I have watched from 11:20 forward, repeatedly, at your explanation of how the signal reference switches from Vgs to Vgd. I recently created a JFET based switching power supply and despite reading the datasheet 100 times, I couldn't explain this exact behavior. It was a desired behavior, but I could not find an easy source documenting this behavior. You have singlehandedly cleared up days of searching in less than 30 seconds. Thank you sir! If you have Patreon, I'd gladly buy you a beer across the internet.

[@jimmydburrell]

Brilliant! Nice design ;) Good video explanation.

[@parapos]

another great video!!

[@Flyrip]

"Made of the finest chinesium so it will never need a reboot" 😂

[@keithking1985]

the time problem you went over reminds of how ground plays it role in signaling through the gate. instead of ground means end of the road.. P.S. my lap top could use this big time, coz of people not turning it off properly and just closing down the lid..... always need to pull the power for 10 or 15 sec's before i use it sometimes.. LIKE TONITE!! ; ) i'll have bar them!!