Hi A white LED is like a fluorescent bulb. The actual LED runs at UV and there are phosphors in it to convert the UV to various colors of visible light. The phosphor mix determines the color balance of the LED. It also adds persistence to the output, just like a CRT.
I do very much agree that you need a proper supply to run the LED's. Rectified AC is *not* the way to go. Bob -----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: Tuesday, September 18, 2012 12:42 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Hi Power LED Light power supply... On Tue, Sep 18, 2012 at 5:21 AM, Bob Camp <li...@rtty.us> wrote: > Hi > > I suspect those same 120Hz sensitive people would not be able to watch TV or > a movie :).... In the old CRT type TV sets, the phosphor has some persistence. Movies are modulated with a square waves, the frame blinks off and goes dark then blinks on. But the LED's brightness is fast enough to track the sine wave and would be bright only for an instant with quick pulses of light. But just as bad as the flicker is that the LED is wasted and spends most of the time being dim. Power supplies are so easy to do that they are NOT the hard part. With LEDS the hard part is the mechanical and optical design. The light must be indirect and defused and to do that correctly and without much waste requires being creative and/or having some metal working skills. Chris Albertson Redondo Beach, California _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.