From: dxmm@albury.nospam.net.au   
      
   On 18/04/14 22:45, Uncle Peter wrote:   
   > On Fri, 18 Apr 2014 12:48:36 +0100, Daniel    
   > wrote:   
   >   
   >> On 17/04/14 23:46, Uncle Peter wrote:   
   >>> On Thu, 17 Apr 2014 13:50:32 +0100, Daniel    
   >>> wrote:   
   >>>   
   >>>> On 17/04/14 10:07, Uncle Peter wrote:   
   >>>>> Can someone confirm that power factor is NOT taken into consideration   
   >>>>> for domestic supplies?  I have a feeling it isn't, but I can't find   
   >>>>> any   
   >>>>> information on the internet.  If it matters, it's a modern (<5 years   
   >>>>> old) electronic meter I have.  The power factor in my house is an   
   >>>>> average of 0.7 so depending if it's charged for or not, my bill   
   >>>>> could be   
   >>>>> completely different.   
   >>>>>   
   >>>> When I last dealt with this, power generator companies "assumed" there   
   >>>> would be an average power factor and set up their generators to handle   
   >>>> that. Your individual house (or, probably, even a small factory) would   
   >>>> not cause much variation in that power factor, considering the   
   >>>> generators are probably supplying hundreds of thousands of homes at the   
   >>>> same time!!   
   >>>   
   >>> That won't apply to switched mode power supplies clipping off the peaks   
   >>> though.   
   >>>   
   >> Wouldn't cause a very big blip in the grander scheme of things.   
   >>   
   >> And what SMPS clips off the peaks?? Usually they vary the switch on   
   >> point in the A.C. waveform.   
   >   
   > You can get power supplies with "active PFC" which is presumably what   
   > you just described.  However the cheap ones have "passive PFC" or no   
   > PFC, so presumably they just top up the bulk capacitors at the peak of   
   > each waveform.  A basic transformer and rectifier will do the same.   
   >   
   What's "PFC" when it's at home?? Power Factor Correction maybe!!   
      
   To the mains supply, most things look like Inductors, which means the   
   voltage waveform and the current waveforms are not in phase. Power   
   Factor Correction  simple means that capacitors are switched in to   
   counter-act the Inductance, so the Voltage and Current are more nearly   
   in phase.   
      
   Active PFC might be changing how a transistor "appears" (more capacitive   
   or less capacitive) to fix the phase angle.   
      
   And, as I typed earlier, your little power supply would have very little   
   effect on the phase angle of your homes mains supply!!   
      
   Now, when your refrigerator's (inductive) motor switches on, now that   
   might have a noticeably affect, but, in the greater scheme of your   
   regional Power companies operations, zero effect!!   
      
   Daniel   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)