Electronics > Electronics

Actual vs conventional current?

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zamboniman60:
When you people are visualizing what schematics do in your minds, do you find it more useful to imagine conventional (+ to -, useful because ALL THE ARROWS ON TRANSISTORS AND DIODES MAKE SENSE) or actual (- to +, what really happens) current? A pet peeve of mine is the fact that many books on electrical engineering never mention conventional current whatsoever, and don't explain why diodes and transistors have their arrows pointing the way they do. Which do you think should be taught?

Admin:
Although this isnt correct, I imagine electrons moving from + to -. (yes, I actually do picture the electrons because it helps me understand the circuit).

This is only because it fits the convention and arrows and such.

This should be the way its taught, but only because it matches convention . . . it gets really confusing otherwise . . .

zamboniman60:
I'm glad to hear that I am not completely insane to imagine electricity as a flow of holes from + to -. I've been reading this 1970's navy manual on electronics (useful so I can understand how to use tubes), and they have a really annoying habit of changing from actual to conventional current and back with no warning whatsoever. I suppose it's no less confusing than "ravel" and "unravel" meaning the same thing... Or flammable and inflammable, or thaw and unthaw.

dunk:
i believe the reason for this is historical.
scientists used to think electrons moved from +ive to -ive. that's why the symbols got drawn that way round.
it would have made sense to early scientists i guess. why else would it be the +ive terminal that gives you an electric shock?

dunk.

Joe:
I had one teacher that said it makes no difference whatsoever, and that the only thing we can see anyway is polarity, so therefore that is all that matters. For the engineer, I think this is pretty much true. Only when studying components at the physical level (as in the physics of how they work) is it necessary to think in terms of electron flow (neg to pos) to know why capacitors, for example, do not charge to the opposite polarity.

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