Alec Cameron said the following to MIKE ROSS on the subject of
solar power in apt? (25 Dec 97  13:22:02)
Long time no see, Alec! Off on a trip someplace? We all missed your
presence. Nice to have you back...
 AC> On (21 Nov 97) MIKE ROSS wrote to Alec Cameron...
 AC> That word of yours "drop" annoys me. It ain't a drop, it is an
 AC> opposing emf. I baulk at the impression that the diode is wasting
 AC> energy, as would an "ohmic" ie resistive device. Getting hot!
 AC> It is behaving instead, as a bucking ie subtractive voltage, and
 MR> stays
 AC> cool with it.
 MR> I'd like to live in that utopia where rectifier diodes have an "emf" and
 MR> never get hot... :-)
 AC> OK it runs less hot! The heat dissipation [watts] within a diode is
 AC> not I think, equal to E times I. Yes there is an ohmic energy loss, yes
 AC> it gets hot but it is less hot than volts times amps would propose.
Most emphatically NO! Unfortunately E times I equals Watts no matter
what you put in the wire, be it a semi-conductor or a semi-trailer.
There is no magical electrical property that lets a diode stay cool and
escape this fact.
 MR> Alec, if you read a little about P-N junctions on Fermi levels, energy
 AC> All too technical for me!
I was only being a bit facetious... aka pulling your beard etc...
 AC> I am victim to the tech education curriculum
 AC> of the 1940s. *Of course* diodes release energy [why else have a heat
 AC> sink!]
 [ . . . ]
 AC> *OPPOSING EMF* is a common enough concept,
To consider a diode as an opposing source of electromotive potential is
perfectly fine when working out nodal equations. However to carry the
concept into a real situation is wrong. Circuit analysis tricks do not
usually apply very well to the hardware.
 AC> Are you happy with the circuit characteristics known as negative
 AC> sequence resistance;  quadrature axis subtransient reactance; imaginary
 AC> numbers; excessive voltage rise along a heavily loaded transmission
 AC> line?
I deserved this one, obviously you got my ribbing...
 MR> Hmmm... which reminds me you may be able to recover some of the
 MR> rectifier's losses by placing it in front of the solar panels?
 AC> Or soft boil an egg in the teapot.  Cheers....ALEC
Sorry man, just couldn't let you get away with the cool diode thing...
It's easy to get confused about this if you were trained in the era of
conduction through vacuum. Luckily I got my training just as tubes were
being phased out so that I did get to learn both worlds so to speak and
I love tubes!
Merry Christmas & Happy New Year to you and yours!
--- Blue Wave/DOS v2.30
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