From: dxmm@albury.nospam.net.au   
      
   On 21/05/14 02:21, Ian Field wrote:   
   >   
   >   
   > "Uncle Peter"  wrote in message   
   > news:op.xf5xhtkzswtmtb@red.lan...   
   >> On Tue, 20 May 2014 12:10:49 +0100, Daniel    
   >> wrote:   
   >>   
   >>> On 20/05/14 06:53, Ian Field wrote:   
   >>>>   
   >>>>   
   >>>> "Daniel"  wrote in message   
   >>>> news:vi84v.62218$%x6.40968@fx16.iad...   
   >>>>> 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:   
   >>   
   >>>>>>> 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.   
   >>>>   
   >>>> Between each peak the reservoir cap sags a little, each peak tops it up   
   >>>> againd and passes a large blip of current doing so.   
   >>>   
   >>> Yeap, but the transformer Secondary's peak voltage  must exceed the   
   >>> cap's voltage to then "top-up" the capacitor.   
   >>>   
   >>>> AFAIK, current regs require a PFC front end on any switcher over 50W.   
   >>>   
   >>> 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, 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.   
   >>   
   >> Inductive and capacitive cancel each other out in a street.  You can't   
   >> cancel out clipping.   
   >   
   > When I put an electronic ballast in the bog luminaire, I left the hefty   
   > PFC capacitor in there to filter spikes.   
      
   Sorry, your bug zapper already had a PFC capacitor *AND* you had to add   
   "electronic ballast"!!   
      
   Something seems wrong there!!!   
      
   Daniel   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)