XPost: alt.home.repair, uk.d-i-y
From: Gothberg"@internet.co.is
On Tue, 25 Dec 2018 18:33:27 -0000, Rod Speed wrote:
>
>
> "William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
> news:op.zulb102po5piw3@desktop-ga2mpl8.lan...
>> On Tue, 25 Dec 2018 17:33:52 -0000, Rod Speed
>> wrote:
>>
>>>
>>>
>>> "William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
>>> news:op.zukr2cpgo5piw3@desktop-ga2mpl8.lan...
>>>> On Thu, 20 Dec 2018 04:22:39 -0000, Clare Snyder
>>>> wrote:
>>>>
>>>>> On Wed, 19 Dec 2018 19:36:51 -0000, "William Gothberg" <"William
>>>>> Gothberg"@internet.co.is> wrote:
>>>>>
>>>>>> On Wed, 19 Dec 2018 17:47:17 -0000, trader_4
>>>>>> wrote:
>>>>>>
>>>>>>> On Wednesday, December 19, 2018 at 11:35:06 AM UTC-5, William
>>>>>>> Gothberg
>>>>>>> wrote:
>>>>>>>> On Wed, 19 Dec 2018 16:21:41 -0000, Mark Lloyd
>>>>>>>> wrote:
>>>>>>>>
>>>>>>>> > On 12/19/18 6:01 AM, William Gothberg wrote:
>>>>>>>> >
>>>>>>>> > [snip]
>>>>>>>> >
>>>>>>>> >> They probably are fairly crude. I know they flicker, for example
>>>>>>>> >> if I
>>>>>>>> >> use my cordless drill, the chuck appears to spin the wrong way
>>>>>>>> >> under the
>>>>>>>> >> LED lighting.
>>>>>>>> > I remember seeing that with a washing machine (under fluorescent
>>>>>>>> > lights). As the tub was slowing down, the row of holes around the
>>>>>>>> > tub
>>>>>>>> > would appear to reverse direction. Same thing with (spoked) wagon
>>>>>>>> > wheels
>>>>>>>> > in movies.
>>>>>>>>
>>>>>>>> It looks absolutely ridiculous with modern cars with LED headlights
>>>>>>>> in
>>>>>>>> films. How hard can it be to put a smoothing capacitor on the
>>>>>>>> output
>>>>>>>> of the power supply?
>>>>>>>
>>>>>>> I've never noticed that. Any films come to mind?
>>>>>>
>>>>>> A lot of Top Gear programs showing the DRLs of cars fitted with LEDs.
>>>>>> With a feature film, they might take the time/trouble/money to do
>>>>>> something to stop it.
>>>>>>
>>>>>>> It seems especially
>>>>>>> weird, since cars have a 12V supply with a big battery to smooth
>>>>>>> anything out. I guess the power supply that reduces that to whatever
>>>>>>> the LED headlights use though might have a switching power supply
>>>>>>> these
>>>>>>> days too.
>>>>>>
>>>>>> AFAIK it's deliberate, making the LEDs operate brighter than they are
>>>>>> capable of, but only 1/4 of the time. Our eyes just see the brightest
>>>>>> part of the cycle, so we think they're four times brighter than the
>>>>>> LED
>>>>>> is really capable of, without overheating itself.
>>>>>
>>>>> That is PWM Overdrive. Peak junction current is over the nominal
>>>>> rating, but the average power consumption is below nominalmaximum
>>>>> current - and the peak lumen output is significantly enhanced without
>>>>> reducing the junction life appreciably.
>>>>> THIS would definitely cause flicker as there is a "significant" dead
>>>>> period between the "strobe flashes"
>>>
>>>> Agreed, although Rod thinks only freaks can see it.
>>>
>>> Its true with car lights.
>>
>> You're obviously wrong,
>
> We'll see...
>
>> just by the number of articles on the internet about it.
>
> That's just the freaks howling about seeing it.
If it were a small number of freaks, there wouldn't so many articles and
studies into it. It is a large percentage of the population that can see it.
Way more than the percentage of vegetarians and disabled, yet they both get
catered for.
>>>> I wonder why none of my houselights use this?
>>>
>>> Hues bulbs do, you can see that by waving something non
>>> transparent past a bulb when looking directly at a lighted bulb.
>>>
>>> Your strip house lights have far more leds so don't need to.
>>>
>>>> Do car lights have to make more brightness from a smaller area?
>>>
>>> Corse they do.
>>>
>>>> Or would flickery houselights annoy people more?
>>>
>>> They don't with Hue bulbs.
>>
>> They don't annoy YOU. They probably annoy others.
>
> You wont find anyone saying that they annoy them on the net.
Depends just how flickery they are. If the frequency is high enough, they
won't bother anyone. Can you set something up to test the light output (or
the voltage to the LEDs) with a scope?
>>>> If it's the extra brightness, I don't understand
>>>
>>> As always.
>>>
>>>> because I have a torch with a single LED and parabolic reflector that
>>>> gives out 20W equivalent without overdrive. Simply have three such
>>>> lamps
>>>> with their own little (only 1.5 inches across) reflector next to each
>>>> other to make the headlamp.
>>>
>>> Even you should have noticed that car headlights are much brighter.
>>
>> A car headlight SHOULD be 60W equivalent.
>
> Wrong, as always.
Back in the days of incandescent lights on cars, every single car had a
55W/60W bulb for it's headlights. 55W for dip and 60W for full.
>> So 6W of LEDs, or a few of my torches per lamp.
>
> Your torches are lying about them being 20W equivalents.
Actually the lie says they're 60W. I measured them as 20W. They consume 2W
and give out 20W equivalent.
>> Quite possible to just have three reflectors just like my torch, mounted
>> together.
>
> Yes, but that's nothing like what real headlights produce light wise.
A real headlight should produce the same amount of light as a 55W
incandescent, which requires about 5.5W of LEDs. Easy to arrange that with
reflectors and cooling without pulsing.
--- SoupGate-Win32 v1.05
* Origin: you cannot sedate... all the things you hate (1:229/2)
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