[time-nuts] Hi Power LED Light power supply...

[Bob Camp]

Hi

The shutter on a conventional movie projector is very much an on / off
device. They run well below 120Hz. The phosphors in a white LED are at least
as long persistence as those in a TV set. There are a *lot* of TV's out
there that refresh at 60 Hz or less.

Bob

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Poul-Henning Kamp
Sent: Tuesday, September 18, 2012 9:05 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Hi Power LED Light power supply...

In message <AC9E4C92327746D4A521FACD35D9D654 at vectron.com>, "Bob Camp"
writes:

>I suspect those same 120Hz sensitive people would not be able to watch TV
or
>a movie :)....

I suggest you either carry out a couple of experiments yourself, or
go a little easy on the irony.

CRTs, and LCDs go out of their way to avoid flickering using physical
or electronic persistence, whereas a naked LED wil happily flash
up to several hundred kHz if you ask it to.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.

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