[time-nuts] Hi Power LED --- Thread Overload

[SAIDJACK at aol.com]

Fellow Time Nuts,
 
in the last week we had more than 50 emails concerning Fedex versus UPS  
shipping and how to package something, now we have a similar number of emails  
about LED lighting.
 
I hope we can end this thread soon, or move it to another discussion group. 
 I for one am getting really tired of deleting 50+ emails every day that 
are not  related to time or frequency metrology.
 
Thanks,
Said
 
That is a very fun prank to do.

Show someone an o'scope with a  flat line on it and hand them a pretzel or
carrot.  

Tell them  that you have implanted several sensors into their brain and you
want to  calibrate them starting with mandibular vibration. 

I have seriously  freaked some people out with this one.

Dave

> -----Original  Message-----
> From: time-nuts-bounces at febo.com 
>  [mailto:time-nuts-bounces at febo.com] On Behalf Of gary
> Sent: Tuesday,  September 18, 2012 12:28
> To: time-nuts at febo.com
> Subject: Re:  [time-nuts] Hi Power LED Light power supply...
> 
> There are ways  for the flicker to be more evident. Don't laugh, but 
> chewing something  hard like a pretzel can bring out the flicker. 
> Basically you can get  beat patterns between the vibration of your eye 
> and the light  flicker.
> 
> There is a common problem with DLP projectors that use  color 
> wheels. You 
> will see reviewers shaking their heads and  eat crunchy food 
> in order to 
> see "rainbows" on the  screen.
> 
> A similar problem occurs with matrixed LED displays  mounted 
> on machinery 
> that has vibration. Very common in  industrial controls since 
> they like 
> LEDs for  readability.
> 
> When I designed the 2nd generation LED display  drivers, I bumped the 
> refresh rate to 500Hz min. That was about 2x the  frequency 
> where I ran 
> out of convoluted experiments to detect  flicker.
> 
> On an analog scope, you can display a flat line and  have it wiggle by 
> eating something crunchy. I don't have an analog  scope on the 
> bench at 
> the moment, otherwise I would figure out  the right 
> circumstances to make 
> that happen.
>  


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