08 Jan 98 11:23, Tim Hutzler wrote to Mike Ross:
TH>I was under the impression that DC has a 100-percent power factor.
TH>Perhaps you can explain how PF is measured.
I will try. Power Factor is a measurement of the in-phase relationship 
between AC voltage and AC current. A power factor of 1 (100%) means that the 
wave form of the voltage is exactly in sync with the amperage. An AC wave 
form rises from 0 (zero) in a positive direction then falls back thru 0 to a 
negative peak then returns to 0. This is 1 cycle. The number of times that 
this occurs in 1 second is the frequency. Amperage can lag or lead the 
voltage (positive PF or negative PF). 
Impedance is a measure of the "resistance" to a change in voltage of a 
device. Usually such a device will contain coils of wire such as a 
transformer or motor.
In DC impedance is not normally a consideration because voltage is constant.
-Joe
jdodson@freewwweb.com
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