Perhaps not black art but in most cases devices can be treated as black boxes
with particular characteristics.
We were taught that the arrow and bar showed the direction that electron flow
was blocked ( by the bar).
Thus the electrons actually went the other way. Probably really originated from
cat's whisker however.
73
Bill wa4lav
________________________________________
From: Amps [amps-bounces@contesting.com] on behalf of Matthew McCloskey
[hidesertdrifter@live.com]
Sent: Sunday, September 01, 2013 3:57 PM
To: amps@contesting.com
Subject: [Amps] Electron vs. Current Flow
When I went to USAF electronics school (1957-1958), very little of the
curriculum included Semiconductor theory,
and of course it did teach Electron flow. About 2 years later we were sent to
classes in Semiconductor theory,
and I had a heck of a time understanding it because of my training in Electron
theory. I used a method
to remember the difference between an NPN, and PNP Symbols using Electron
theory. Since Electrons flows against the Arrow,
when the Arrow points to the Emitter it is a NPN, because an Electron travels
from Neg (Emitter) to Pos.
(Base), and visa versa. So using this convention I managed to have a hard time
understanding Semiconductors because
I applied Electron flow to them. I could troubleshoot them using test points
and voltages from a schematic, butthey were always a black art to me. Well
after reading all the posts in this reflector, I decided to apply Current flow
theory to Semiconductors and re-read the ARRL handbook section on solid state
devices. Well guys the Transistor is not a black art anymore, its just in the
gray zone although I still do use electron theory for tubes. I can look at a
transistor drawing and make sense of it now, and I want to thank all of youfor
opening my mind to use both conventions, depending on the circuit configuration
i.e.-tube or semiconductor.In my case It makes a big difference in
understanding how solid state circuits work. I've been fascinated with
electronics since I was a kid, but I am very mechanical in my thinking, and if
I can't SEE some thing doing its thing, I have a hard time understanding it.
Call me ignorant, or slow (I am both), but its been a difficult love
affair with electronics. MattAD7XN
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