Hi Craig On (16 Nov 97) Craig Healy wrote to Alec Cameron...
 CH> Re: Diode in solar system..
-> If you find the concept of 0.7 being an emf unconvincing, then put a
-> voltmeter across the diode while increasing/ decreasing the panel
-> output eg by shading it. You will see that the 0.7v does not change.
 CH> Yep!  Not disagreeing with that at all.  I have used series-connected
 CH> diodes in a number of applications to get a fairly stable fixed
 CH> voltage drop.  Works well.
 CH> I think what we have is a terminology difference, not an "electrical"
 CH> one.  To you, the drop across the diode is fine.  To me, it's
 CH> something I'd like to find a better way to do.  Nothing mutually
 CH> exclusive there!
That word of yours "drop" annoys me. It ain't a drop, it is an opposing emf.
I baulk at the impression that the diode is wasting energy, as would an
"ohmic" ie resistive device. Getting hot!
It is behaving instead, as a bucking ie subtractive voltage, and stays cool
with it. Being an HVAC grid man I am VERY conscious of the fact that voltage
is a number not a figure of merit. Many HV lines deliver scads of MW into
loads, where the load V often exceeds the sending V. That is, the  voltage
rises down the line. This has NOTHING to do with solar panels, except to
compel a bit of lateral thinking and willingness to comprehend the seemingly
ridiculous!
Cheers.......ALEC
... ...Starting from a conclusion is bad research [John Harrison, Dunblane 
SCT]
--- PPoint 1.92
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