Field Effect Transistors, Part 1

This is a simple explanation of what a field effect transistor is, how it can be used, and how it's compared to the bipolar junction transistor. Donations: http://bit.ly/icYMcw Thanks!

Info on early semiconductors and transistors:
http://www.porticus.org/bell/belllabs_transistor1.html

Part 1 of 2.

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[beinganangeltreon]

Awesome video

If a person made a FET with | v | actual physical shape variations could the output create a geometrically true trigonometric wave like ~ ? Then a kind of funny synthesizer ic could be made that just had like a few thousand premade FET channel wavepaths giving a bunch of kind of perfect analog waveforms I heard that true trig function waves like ~ previously used multiple components yet it seems like a sculpted FET could make repeated analog waves

[SteelWheelsDown]

@beinganangeltreon I think the equation I noted (in part 2) is based on a channel that's a rectangular slab shape. The conductance changes as the cross sectional area changes, and that's dictated by the channel shape as well as the gate area. If the channel had a hyperbolic cross section, then you could be right.

I have taught you all I can, young Jedi. You must now venture forth to a faraway planet and seek a greater master than I. May the Force be with you.

[TheMJDefenderz]

Hey you were a great help!! thanks a lot. I just have one doubt though... Does the drain-source voltage have to be forward biased or reversed biased? And why? Coz I noticed for N-channel it was RB and for P-channel it was FB... And thanks again, you just saved me a day of confusion and referring the books.!! :)

[SteelWheelsDown]

@TheMJDefenderz, theoretically, no, source and drain are the same, but in reality the drain end of the channel is doped a bit differently than the source end, so you should keep the source more negative than the drain in your circuits.

[xweidemann]

Sorry, dont want to be a nert, but Lillienfeld never realy BUILD a transistor because pure silicon material, which is needed, was not avaiable in the twenthies. So it was just theory and definitly there had been no "radios" which were based on transistors.

Look it up in wikipedia.

[SteelWheelsDown]

@xweidemann - I've added a link to an article in the video description. It states that Lillienfeld built some MOSFET-like devices, but they weren't mass-produced for another 30 years. Lillienfeld WAS your daddy. As for Wikipedia... I wasn't alive in the 20's, so I don't know personally, but I have read references to early FETs in the 1920s. Who wrote that Wiki article? No idea. How much did you pay to see that article? Well, that's exactly what it's worth.

[pimvda]

Very well explained, thanks a lot.

[polaris2341]

Thanks Excellent video about  ingenious & elegant device FET, useful video for hobbyists like myself I am sure also for electronic engineering students.Explains better than textbooks

[SRakash]

You sir are a life & grade saver !! thank you so much

[Shockszzbyyous]

@ATouchOfOrchestra that makes sense thanks :)

[ATouchOfOrchestra]

@Shockszzbyyous Nope. Usually, the source terminal is used as a common terminal (grounded) between gate & drain.Notice here that source electrode refers to the source of injection of charge carriers (holes or electrons).Hope it helps.

[Shockszzbyyous]

and same happens between drain and gate?

[busybjorn]

As with many things in electronics i've been asking myself over and over again how FETs work. It only takes a good and clear explanation. Thanks !