XPost: alt.home.repair, uk.d-i-y   
   From: rod.speed.aaa@gmail.com   
      
   William Gothberg <"William Gothberg"@internet.co.is> wrote   
      
   > Do switch mode power supplies flicker in time with mains?   
      
   No.   
      
   > Specifically LED power supplies in commercially available domestic lamps.   
      
   None of mine flicker at all.   
      
   > By in time, I don't mean at the same 50/60Hz, but anchored to it.  I.e. if   
   > you have several such lamps each with their own built in supply, will they   
   > all flicker in time, using the mains frequency to keep them in time, or   
   > will they be random, making the room overall not flicker due to them all   
   > being random?   
      
   None of mine flicker at all.   
      
   > And is there any way I can test this?   
      
   Yes, Get or make a strobe disk or use   
   one of the original LP disks that has   
   a strobe disk on it and see what it looks   
   like with the lights illuminating it. You'll   
   get it appearing to freeze when rotating   
   if the light level is varying in synch with   
   the mains frequency.   
      
   > I tried taking photos of them, but my camera only goes as fast as 1/2000th   
   > of a second, which shows all the lights at the same brightness each time,   
   > I suspect the flicker is above 2000Hz.   
      
   Or they don't flicker at all. No reason why a proper   
   switched mode power supply needs to have any   
   AC component at all on its output. The cruder   
   ones may well do.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)