The function can be understood as a traffic cop at the intersection of a major road and a small 1 lane road.

He has instructions to only let cars down the major road if cars also come down the small road.

When a small trickle of cars come down the small road the intersection can act like a dimmer switch. It can also take a very small signal, and with a secondary more powerful input, amplify it.

But if you quickly alternate between no cars and lots of cars that dimmer switch acts like a toggle switch giving you 1s and 0s.

The physics is basically, when you sandwich two elements in close proximity that give up their electrons in a very specific way you get the macro phenomenon described above.

The reason the elements give up electrons this way also happens to be at the heart of a lot of cool concepts of math and is a demonstrable proof of some physics that used to be just theory. Learning the physics of transistors can teach you concepts that tie together the history of science from Ancient Greece to Quantum physics.

“Amplification” has to be one the most misunderstood concepts In electronics

No signal is really “boosted” by some weird process. What happens is a very powerful DC signal (i.e constant) is selectively allowed through, being mediated by the input signal. The “volume knob” on a power amp works by ATTENUATING that constant DC signal prior to “amplification”

This feels like a typical political comment (or youtube ad) but applied to electronics. Calling the common model false, writing it off as "weird", and then making up a new model with a hint of truth but still less explanatory power than the original one. Like, just don't.

It seems like you're stuck focusing on where the energy comes from, hence wanting to talk about the "powerful DC signal" (eg power supply). But the concept of amplification says nothing about where the energy comes from - it's merely talking about the magnitude of a signal being increased. You can also say "an audio amplifier requires a power supply". Multiple concepts apply to the same situation! This is true everywhere in life, but it's easier to ignore for software and impossible to ignore for electronic design.

Thanks, now my left ear hurts. Haha. All I know is it goes to 11

(I love that you’re passionate about the details and it is certainly beautiful to imagine it the way you describe. Im picturing an ocean and the mediation little birds flying down and sculpting the crests of waves. The attenuation is like the Venetian MOSE flood barriers.)

Oh, I guess those intersections with sensor controlled lights for a tiny side road are just JFETs. Maybe that will make me less annoyed at having to wait.

Now you know how your electrons feel!

The BBC's Shock and Awe: The Story of Electricity [0] documentary really made it click for me. The historical development and the conceptual development are woven together nicely.

[0] https://en.wikipedia.org/wiki/Shock_and_Awe:_The_Story_of_El...

No. This book won’t teach you that because based on the author’s previous work he doesn’t either. He knows how to sell books.

If you really want to know how transistors work and how to use them properly it’s going to be difficult as they sit on a fairly large pile of algebra and theory. If you don’t know this you might be able to get simple circuits working by cutting and pasting bits but you won’t be able to get past that ever.

The best references on this are actually The Art of Electronics. Not necessarily the main book but the associated student manual. Also the book Experimental Methods in RF Design by Wes Hayward actually has the most useful functional description and modelling approach of transistors.

OK I get how they work conceptually, I get how they work physically, but when I actually try to build a circuit with them it never works.

You clearly missed something in the former or latter or do not know how to verify if stuff is as expected.

Usually I build out the DC bias model (static operating point), test it in LTspice, then add the AC/small signal model on top. Or large signal model for switching etc. Everything generally works unless I did something stupid or it’s RF where things get a little less predictable.

What is the most challenging concept about transistors? I think the classic valve analogy (AKA Art of Electronics "Transistor Man") works to a large extent. To fully understand the physics requires a lot more but in between, there are relatively simple equations that describe the main current flow as related to the control terminal's voltage or current depending on the transistor type.

To go from single transistor to multi-transistor circuits was a big leap for me, but most of it is understanding how particular subcircuits work and recognizing them as blocks of a larger circuit.

BJTs were a real pain. Uncooperative exponentials fighting each other, or something like that, if I haven’t managed to forget successfully…

The exponential model tying collector current to base-emitter voltage is why I think most old-school references just treat BJTs as a fixed gain base-current amplifier. Of course it doesn't help that the gain is unknown and varies with process parameters!

The classic Voltage as Water in a pipe, or check valve comparison are destructive and misleading analogies that do not demonstrate the behavior except in isolation, and that narrow scope of isolation isn't provided leading towards purposeful struggle.

The ideas and practices of the gnostics in general are just stupid.

If you can't explain how a PN junction, or its composites actually function simply, you don't understand what you are talking about. As simply but not more simply than necessary, without using math.

I actually have the 3rd edition of this book, and, yea I think it explained transistors pretty well.

Mind, I don’t remember any of it, I never applied it, but at the time, it explained it to me.

It helps a lot understanding diodes first. Like, really understand them. Then transistors are built on top of that knowledge.

My recommendation - start with FETs (MOSFETs) for switching instead of BJTs. FETs are voltage controlled devices, which maps more naturally to how people think about electronics without the math-heavy analysis.

Depends if you want the engineer’s perspective or the device physics perspective.

I think the MOSFET circuit diagram has always made more sense to me because you can see intuitively see the “plunger” as the control input.

Honestly just spend a few hours talking to Claude about them, I had a few breakthrough moments doing that.

put this prompt and share the response:

You summarize the past convestion in this thread. - Start with a overall summary in a single paragraph - Then show a bullet pointed list of the most interesting illustrative quotes from the piece - Then a bullet point list of the most unusual ideas - provide a longer summary that covers points not included already - Finally, Step by step/phase by phase understanding of the ideas discussed above