XPost: alt.home.repair, uk.d-i-y   
   From: rod.speed.aaa@gmail.com   
      
   "William Gothberg" <"William Gothberg"@internet.co.is> wrote in message   
   news:op.zuaweippo5piw3@desktop-ga2mpl8.lan...   
   > On Thu, 20 Dec 2018 01:31:30 -0000, Rod Speed    
   > wrote:   
   >   
   >>   
   >>   
   >> "Brian Gaff"  wrote in message   
   >> news:pvdu3r$oo6$1@dont-email.me...   
   >>> Well the answer as in many things these days is it depends.   
   >>> Some are very simple and do have a kind of pulsing taken from ripple on   
   >>> the mains. Others seem to not do this, indeed poking a phototransistor   
   >>> connected to an amplifier shows many different results. the same seems   
   >>> to   
   >>> go for CFLs as well.   
   >>> You would need to know what circuit they were using etc to figure out   
   >>> why.   
   >>> One particular led in a stood across the road has a 1khz whine when   
   >>> point   
   >>> the device at it but modulated onto a 100 hz buzz.   
   >>>   
   >>> I often wonder if there is some jiggery pokery going on to drive leds   
   >>> hard   
   >>> for split seconds to make them brighter.   
   >>   
   >> Yes, there is, particularly with the brighter ones like car headlights   
   >> etc.   
      
   > Those designers need to do more research and realise that a lot of the   
   > population have eyesight good enough to detect that flicker   
      
   In fact fuck all of them do and they clearly don't themselves.   
      
   > and should therefore increase the frequency of the flicker, or they're   
   > causing distractions and a danger on the roads.   
      
   Clearly those that set the standards for cars know otherwise.   
      
   You're just a freak.   
      
      
   >>> "William Gothberg" <"William Gothberg"@internet.co.is> wrote in message   
   >>> news:op.zt9okmwvo5piw3@desktop-ga2mpl8.lan...   
   >>>> Do switch mode power supplies flicker in time with mains?  Specifically   
   >>>> LED power supplies in commercially available domestic lamps.  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?  And is there any way I can test this?  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.   
   >>>   
   >>>   
      
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