[time-nuts] White LED's

[Robert Atkinson]

Hi,I'm late to the thread (as usual), but have looked at these LED's in the past. It was for a biotech imaging application. There are two types, a red/green/blue cluster or a blue / near UV LED with a white phosphor. These phosphors seem to have a fairly continuous spectrum, at least compared to fluorescent lamps and HID lamps. What surprised me was the speed. We had a strobe application for which a xenon strobe was proposed. I tried LED's (our optics "expert" said even normal LED's would not be fast enough). I knew normal LED's are fast enough but was unsure about the phosphor types. To my surprise they where faster than the xenon tube! They were faster than my detector. This has has an impact on the mill illumination in that you can get strobe effects that could cause you to think the spindle was stationary when it was not. This is more of a problem in a noisy environment than a home shop with only one machine running.  
Robert G8RPI.

--- On Sat, 30/1/10, J. Forster <jfor at quik.com> wrote:

From: J. Forster <jfor at quik.com>
Subject: Re: [time-nuts] Conducting Bench Top Material
To: "Magnus Danielson" <magnus at rubidium.dyndns.org>
Cc: "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
Date: Saturday, 30 January, 2010, 1:15

To my aging eyes, the flashlight looks distinctly blue-white. I don't know
how these particular LEDs are built, but the unit is less than a year old.

-John

===============


> J. Forster wrote:
>> Attached is a spectrum of a "white" LED Flashlight. My diode
>> spectrometer
>> does not go further than the limits shown.
>
> Looks pretty continuous to me. Great. I know there is non-continuous
> LEDs out there, but I hope they will fade to grey while continuous takes
> the market.
>
> Cheers,
> Magnus
>
>



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