[Heathkit] F/S Voltage Reducer

[k6uuz@juno.com]

Hi Bob;

The only thing wrong with your theory is that a device designed for 122
volts will have a higher impedance (resistance) than a device designed
for a lower voltage, thereby drawing less current. The load is not the
same. The watts will be the same. Remember it's P=E X I. More E and less
I equals the same power. Here is an example of my contention. Take a load
of 100 Ohms across a voltage of 100 Volts with a current of 1 Amp for a
power consumed of 100 Watts. Now using the same load , increase the
voltage to 120 Volts. The current is now 1.2 Amps. Both the voltage and
current increase, for a power consumption of 144 Watts. Thus, a voltage
increase of 20% caused a power consumed increase of 44%. As you point out
it is E SQUARED over R or I SQUARED times R. I think this is why so many
power transformers fail in old equipment operating on todays higher
voltage.

Ed

On Sat, 16 Mar 2002 15:37:52 -0800 Bob W7AVK <rsrolfne@atnet.net> writes:
> Ed - May be, not sure.  But one interesting fall out is that if you 
> have the
> same load or number of lamps when you increase the voltage you are 
> able to
> "sell" more power.  Remember its e squared over r.  The power demand 
> meter
> takes this into account as it measures both current and voltage plus 
> phase
> angle.  The difference is just enough.  <grin>
> 
> Remember most power companies would kill to get a 5% or so increase 
> in
> billings while not doing a thing except turn a knob.
> 
> Again, have no idea, but makes a good story.
> 
> 73  Bob  W7AVK