This is only slightly related to the original topic, and 'way off the deep end
in terms of how relevant it is to everyday life, but... In semiconductor
physics, a 'hole' is a theoretical construct used to calculate transistor (or
diode, or FET) performance. As many of you no doubt know. transistors are
commonly available in 'NPN' or 'PNP' types. In NPN transistors electrons are
largely responsible for the current flow and gain characteristics, while in a
PNP transistor, the 'holes' determine the current and gain. The interesting
thing (if you're an electro-geek like me) is that electron mobility is about
three times as large as hole mobility, which means that a PNP (or for similar
reasons, a P-channel MOSFET) transistor has to be significantly larger than an
NPN type to give equivalent performance.
The circuits in which NPN transistors are used typically use the most negative
potential as the 'common' between the various portions of the circuit, but the
switch to negative ground in automobiles predates the use of electronics by
about a decade.
Theo Smit
tsmit@novatel.ca
B382002705
> -----Original Message-----
> From: Steve Laifman [SMTP:laifman@flash.net]
> Sent: Thursday, January 28, 1999 8:59 PM
> To: Mark Rudnicki
> Cc: tigers@autox.team.net
> Subject: Re: Positive and/or negative earth: Why on earth?
>
>
>
> Mark Rudnicki wrote:
>
> > Someone once told me that there is actually something that does flow
> > from the positive to the negative side of a circuit, and that is a
> > "hole", or a positively charged particle that somehow shows up when an
> > electron gets moved. ........ But I digress...
> >
> > Mark Rudnicki
>
> The 'something' that moves from the 'positive' to the 'negative' terminal
> is called 'current' (or 'amps').
>
> Electrons, not caring what man's inaccurate understanding of it's nature
> is, merrily flows from the abundance at the negative pole 'downhill' to the
> 'sink', or positive pole.
>
> It really doesn't matter, except in some instances of galvanic corrosion in
> pipes, but not on our rubber tired cars. Unless, of course, you use the
> wrong component. Then all the smoke leaks out.
> --
> Steve Laifman < One first kiss, >
> B9472289 < one first love, and >
> < one first win, is all >
> < you get in this life. >
>
>
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