Transistors 101 ep2: Current Sources

Illustrating the simplest transistor model - regulating the base-to-emitter voltage, and building current sources based on that model.
Schematics: github.com/ken...
TIMELINE:
00:11 Intro
00:35 Ignoring transistor models (for now)
02:27 The simplest transistor model
03:24 A simple current source
04:42 Saturation behaviour
06:18 An LED dimmer
07:17 Cutoff behaviour
08:11 Testing the LED dimmer
09:02 Recap - three operating regions: active, saturation, cutoff

[@josephjorgensen3282]

I am an electrician and starting a 4H group on electrical and I can say I appreciate all the free classes amazing people like you are willing to share with everybody thank you. I know that the kids will make leaps and bounds ahead of my understanding before I know it and I need all the info I can gather to help them.

[@KludgesFromKevinsCave]

Teaching kids is always great! Good to hear you're passing it on!

[@CircuitDuty101]

A good example of where a microcontroller can be substituted by the classic 555. Thanks for educating us!

[@krakkus]

Great explanation! Love the graphic works also :) I try to learn as much as I can from different view points, so I can make circuits intuitively, and you help me a lot with that!

[@bleeghboy3997]

You are awesome! Keep it up you will help many people

[@bitlong4669]

Love way you explain things. Subbed!

[@Stelios.Posantzis]

Excellent tutorial. There is a detail that is needed, however. At 7:17 a new rule to those stated as 2:35 is introduced. This rule has already been stated at 1:41 as "The transistor is valve, not a pump." This should be added (i.e., written), however, in the list at 2:35 as "The transistor is not a source of energy (i.e., it cannot generate energy on its own).".

[@KludgesFromKevinsCave]

@@Stelios.Posantzis thanks for the tip. I try to be careful about such things, but sometimes we all falter.

[@Stelios.Posantzis]

@@KludgesFromKevinsCave Yes, that is very true and besides, t's a minor detail (because the rule is already mentioned earlier). I just put it there because it raised my curiosity that one could describe most simple transistor circuits usefully with just two rules. Even with this third rule, I'm curious to see how many circuits can be described (and which ones cannot).

[@ultrasparc]

❤

[@electronicphilia1687]

Thank you sir

[@KludgesFromKevinsCave]

My pleasure. (I enjoy teaching!)

[@arashyusefi1889]

Thanks 🙏👍💯😊

[@KludgesFromKevinsCave]

Always a pleasure! (I enjoy teaching!)

[@theshadypersonify]

MORE I NEED MORE DAMNIT!!!!!

[@emanuelguadamuz3738]

Yeah! Give likes and subscribe to keep the knowledge...

[@KludgesFromKevinsCave]

Glad you found it helpful!

[@theshadypersonify]

BUT WHAT about micro controller power mosfet circuits?? to drive something between 12 and 20 volts powered by a 0-5A and 0-20V foot powered generator

[@KludgesFromKevinsCave]

I'll probably get into some power MOSFET circuits at some point, but I'm trying to cover the basics! (Never designed a regulator for a bicycle generator, sounds like an interesting project at some point...)

[@pibbles-a-plenty1105]

For those millions of us who are language compromised a little less unnecessary prose would be helpful. Example: "A transistor is not a pump...." That's extraneous. Who ever in my 82 years ever said that a "transistor is a pump"? Hmmmmm.....? The water pipe analogy is sufficient. Keep it simple, stupid (KISS method).

[@KludgesFromKevinsCave]

Sorry, I do tend to ramble, don't I? I'll try to keep it simpler.

[@fransmurati2370]

Dont tell but show

[@KludgesFromKevinsCave]

I try to do both... build one actual example every time.