RE: Re: Energy saving device - fact or fiction?

["Richard Lists" <rich_lists@xxxxxxxxxx>]

No, since the power you get for all the current for the reactive
component
of the load is zero, and you are still going to be paying for all the
resistive losses on your side of the meter.



About the only usable way to get more power then you pay for is if the load
only takes current at the crests, and you have a crappy electronic meter
that averages the current rather then being a true watt meter. The old
metal
disc meters are surprisingly good at calculating current on moderately
stupid loads, some electronic ones are not, but since they have a nice
digital display on them people believe them as faultless (think the
kill-a-watt meter and similar for junk measurement connected to a nice
display)



That's what a lot of people think power factor is measuring, but it's not.
A
non linear load like a pc power supply doesn't really have a simple power
factor as its current is not a sinusoidal wave so it can't be a simple
shift
from the voltage. THD is one way of looking at it, and it is a concern with
places installing hundreds of crap power supplys where they once had nice
resistive loads in the form of compact fluro bulbs.





From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On Behalf Of
Mal Lansell
Sent: Thursday, July 24, 2008 2:16 AM
To: ukha_d@xxxxxxx
Subject: [ukha_d] Re: Energy saving device - fact or fiction?





Does that mean that from a domestic consumer's point of view,
devices with worse power factors are to be preferred (i.e you're
getting more energy than you're paying for)?

Mal





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