To whom it may concern: N vs. P channel MOSFETs.

[ElectroIrradiator]

(Yes, I do believe this is in the right forum section. )

Please be adviced that usually you[1] cannot replace an N channel MOSFET with a P channel ditto without suffering some dire consequences. That is why the first replacement MOSFET instantly blew up when you applied power. You shorted out the battery through the body diode, and the current was only limited by the DC resistance of the transformer.

Otherwise enjoyed the video as always.

[1] Message meant for a fairly narrow selection of 'you'.

[McBryce]

That's a VERY narrow "you" indeed. Any chance of a link to the video?

McBryce.

[ElectroIrradiator]

Apparently Shahriar and I were typing our respective posts at the same time. 

Edit: I spelled Mr. S' name incorrectly...

[McBryce]

It wouldn't be a Shahriar video if nothing exploded or caught fire

McBryce.

[dadler]

I am supremely confident that Shahriar knows the difference between P and N channel mosfets, considering he has a Ph.d in EE and works at Bell Labs (engineering manager, designing microwave-frequency ASICs)--in the building where the transistor was invented.

[ElectroIrradiator]

I am supremely confident that Shahriar knows the difference between P and N channel mosfets, considering he has a Ph.d in EE and works at Bell Labs (engineering manager, designing microwave-frequency ASICs)--in the building where the transistor was invented.

I know about his background in general terms.

I am also supremely confident that we all make those mistakes from time to time.

[MagicSmoker]

...I am also supremely confident that we all make those mistakes from time to time.

Yes, this. I am always impressed when someone with a stellar pedigree does something exceptional stupid but still owns up to it; conversely, I am totally unamused when some wet-behind-the-ears intern blames an incomplete datasheet or the like for his/her failure.

[dadler]

In this case though, Shahriar just showed the wrong datasheet in the video. The newly-toasted mosfet in question was indeed N channel and actually only rated for 400mA. Hence why the to-220 mosfet was getting super hot, as the dc converter circuit really pulls a lot of current.

[Hugoneus]

I just saw this!

In this case I showed the wrong datasheet in the video. As I was searching for replacement parts I downloaded many datasheets in the process. I added a note to the video.

Indeed if a PMOS would be used, it would put the DC-DC converter in positive feedback and would surely destroy the device in question.