On 21/05/14 06:38, Ian Field wrote:


wrote in message
news:alpine.BSF.2.00.1405200925160.13722@bunrab...

On Tue, 20 May 2014 12:10:49 +0100, Daniel
wrote:

Don't know!! The impression I got was that domestic mains supplies PF
varied reasonable as it was, due to domestic fridges, fluoro's, T.V.'s,
etc, switching on and off at different times,
They switch on/off during few cycles (allowing for a starting surge)
and run/don't run for many cycles, so the switching on & off only
matters for the overall load. The type of load does matter.

that the major power
suppliers did not worry about the domestic situation .... but in
industrial situations, yes, the major power suppliers could/would
require PF correction.
Or they bill appearant power & the major users /want/ PF correction,
Note that if you use a lot of reactive power it adds to the current on
the grid and the power company still has to put in heavier wire, so it
does cost them /something/.

On Tue, 20 May 2014, Uncle Peter wrote:
Inductive and capacitive cancel each other out in a street. You
can't cancel out clipping.
But the clipping occurs with a relatively constant phase. It may
create a nasty current waveforms which can be a problem but that's not
what power factor refers to.

Its not power factor as I understood it to be, but it appears to have
become trendy to refer to any AC current waveform distortion as a PF issue.

In any event; the circuitry to eliminate the current blips as the
rectifier tops up the reservoir has become generally referred to as
power factor correction.

Well then, what "has become generally referred to as power factor
correction" is *WRONG*

Daniel