XPost: uk.d-i-y, alt.home.repair
From: Gothberg"@internet.co.is
On Thu, 20 Dec 2018 11:57:01 -0000, whisky-dave wrote:
> On Wednesday, 19 December 2018 16:35:05 UTC, 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?
>
> It's easy but that isn't the point. The most efficient way of driving to
make maximium power into the LED means yuo have to pulse the LED's. Using a
capcitor to smooth out the DC is yet another mode of inefficincy as it would
get warm due to current
flow. Indictors in series might be better but then you run the risk of 'radio'
interference.
Being inefficient would presumably make it impossible to get enough brightness
out of LEDs that fit into the lamp holder. The LEDs would get too hot trying
to give out enough brightness for a car headlight.
However cars vary a lot, some are easy to detect flickering, some difficult,
and some impossible (with the naked eye). Perhaps they just use a higher
frequency?
Taillights are pretty bad on a lot of cars, as they dim the brakelights by
deliberately flickering them.
--- SoupGate-Win32 v1.05
* Origin: you cannot sedate... all the things you hate (1:229/2)
|
