Re: Controlling Holiday Lights

[sylvan butler <ZsdbUse1+noZs_0610@xxxxxxxxxxxxxxxxxxxxx>]

On Mon, 23 Oct 2006 23:48:07 -0400, Marc_F_Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx> wrote:
> On Mon, 23 Oct 2006 18:13:07 -0600, sylvan butler
><ZsdbUse1+noZs_0610@xxxxxxxxxxxxxxxxxxxxx> wrote in message
><slrnejqmkj.a3i.ZsdbUse1+noZs_0610@xxxxxxxxxxxxxxx>:

>>> (Q: Do incandescent lights flicker when run on 50 hz power?)

>A:  No, because incandescent lights are very, very slow.

>>Q:  Do fast acting lights (LEDs, fast phospher in fluorescent tubes,
>>CRTs, LEDs, etc) flicker when run on 50hz power?

> They do not turn on-off faster than the human flicker fusion frequency which
> is what I wrote.

But they do.  I and many others see the flicker from LEDs run on
unfiltered 60hz A.C.  simply by turning ones head causing eyes to sweep
past the LEDs.  Many people complain of this with LED christmas lights
and night lights.

Fluorescent lighting phosphers are a bit slower, and the 120/sec
flashing is much faster, but they also produce easily discernable
flicker that bothers many people and is proven to exhaust eyes even for
those people who are not consciously aware of flicker.

sdb
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