XPost: uk.d-i-y, alt.home.repair   
   From: Gothberg"@internet.co.is   
      
   On Thu, 20 Dec 2018 21:53:44 -0000, %  wrote:   
      
   > On 2018-12-20 2:48 p.m., William Gothberg wrote:   
   >> On Thu, 20 Dec 2018 21:25:45 -0000, %  wrote:   
   >>   
   >>> On 2018-12-20 1:56 p.m., William Gothberg wrote:   
   >>>> On Thu, 20 Dec 2018 20:40:26 -0000, %  wrote:   
   >>>>   
   >>>>> On 2018-12-20 1:30 p.m., William Gothberg wrote:   
   >>>>>> On Thu, 20 Dec 2018 19:11:36 -0000, Rod Speed   
   >>>>>>    
   >>>>>> wrote:   
   >>>>>>   
   >>>>>>> "William Gothberg" <"William Gothberg"@internet.co.is> wrote in   
   >>>>>>> message   
   >>>>>>> news:op.zubnqbkho5piw3@desktop-ga2mpl8.lan...   
   >>>>>>>> On Thu, 20 Dec 2018 09:36:02 -0000, Jon Fairbairn   
   >>>>>>>>  wrote:   
   >>>>>>>>   
   >>>>>>>>> "William Gothberg" <"William Gothberg"@internet.co.is> writes:   
   >>>>>>>>>> Agreed. All I can detect (with my digital camera) is that   
   >>>>>>>>>> one brand of LED light I have flickers about 5 times less   
   >>>>>>>>>> (not sure if it's smother or faster) than the others.   
   >>>>>>>>>   
   >>>>>>>>> Try a longer exposure and move the light rapidly relative to the   
   >>>>>>>>> camera.   
   >>>>>>>>   
   >>>>>>>> I wonder, if I fed the lamps with mains voltage DC, simply a bridge   
   >>>>>>>> rectifier and a huge capacitor, they'd reduce their flicker.   
   >>>>>>>   
   >>>>>>> Wont work at all if they use capacitor droppers and   
   >>>>>>   
   >>>>>> I made a few of those to power LEDs to indicate the function of my   
   >>>>>> central heating.  I'm looking inside the flickery lamp just now (£15,   
   >>>>>> 20W).  Without undoing the glue holding the PSU onto the inside of it,   
   >>>>>> all I can see is probably: the mains going through a large bipolar   
   >>>>>> cap,   
   >>>>>> a tiny resistor (to discharge it safely?), a bridge rectifier, another   
   >>>>>> very large resister (to limit the LED current more accurately?),   
   >>>>>> then a   
   >>>>>> 400V 4.7uF capacitor (which is bulged).  A capacitor dropper with a   
   >>>>>> rectifier and smoothing capacitor after it?  The one I made has no   
   >>>>>> smoothing cap, just mains to cap to resistor to bridge to LED.   
   >>>>>> Perhaps   
   >>>>>> this bulged cap is why I'm getting flicker, I'll try replacing it   
   >>>>>> tomorrow.   
   >>>>>>   
   >>>>>>> they very likely do because those are the only cheap   
   >>>>>>> droppers for dropping such a large voltage.   
   >>>>>>   
   >>>>>> Aren't miniature SMPS units pretty cheap?  I just bought a 12V 6A SMPS   
   >>>>>> for £4.50.  Designed for powering LEDs - but I've looked inside it and   
   >>>>>> it's definitely a switched mode, not a capacitor dropper.  Now this   
   >>>>>> flickery LED lamp I'm looking inside, it's about 20W, so 12V at 2A is   
   >>>>>> all that's required, it could have had an SMPS in it similar to the   
   >>>>>> one   
   >>>>>> I just described.   
   >>>>>>   
   >>>>>> I'm now looking inside one of the better LED lamps (the non-flickery   
   >>>>>> model).  It has a basic SMPS inside it.  They're 9W and £4 each for   
   >>>>>> the   
   >>>>>> whole lamp.  I'm sure it's more than just a standard SMPS though,   
   >>>>>> because when some LEDs fail short circuit (it has about 40 in series),   
   >>>>>> the voltage coming from the PSU drops, to maintain the correct current   
   >>>>>> for the remaining good LEDs.   
   >>>>>>   
   >>>>>>> Very easy to try tho and see if it works.   
   >>>>>>   
   >>>>>> Looks like it would help the better ones, but not the crap one.   
   >>>>>> Better   
   >>>>>> (as I only have a few crap ones) to stick a bigger smoothing cap   
   >>>>>> inside   
   >>>>>> those.  For the good ones, the only problem I can foresee with the   
   >>>>>> external smoother, is overloading the lamp's bridge rectifier, as it   
   >>>>>> will only be conducting on two of the four diodes.   
   >>>>>>   
   >>>>>>>> The cheap shit LED lamp I have that actually flashes at 100Hz would   
   >>>>>>>> most   
   >>>>>>>> likely get much brighter and burn out, so I'd have to adjust that,   
   >>>>>>>> but the   
   >>>>>>>> others which only flicker 8% would just get 4% brighter.   
   >>>>>   
   >>>>> you could use being 4 % brighter   
   >>>>   
   >>>> That would make my IQ 140.   
   >>>>   
   >>>> Was the above too difficult for you to discuss?   
   >>>   
   >>> I Q's are the lamest oldest forgotten tests of them all ,   
   >>   
   >> You're just jealous.   
   >>   
   >>> are you excited this is going to be how usenet is for you for the next   
   >>> 20 - 30 years   
   >>   
   >> Be more specific.   
   >   
   > no and start getting used to the idea that i don't do what you order   
      
   No point in you telling me something if you won't back it up.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)