If there's any discernable flicker at all in a non-moving string, it's being run off 60Hz, probably with 120V dropped across the whole string, because it's cheap. As you say, any DC driver whatsoever will fix the problem. (We do flicker some of our LED drivers but in the megahertz range.) However, an interesting proviso there is the non-moving part. If either the LED's or the person viewing them are in motion, *particularly* if the person is reading or rapidly looking from one side to the other (as you do when you drive) the safe frequency rises dramatically. There's research out there that indicates people exhibit signs consistent with eyestrain from flickering lights at strobe rates of over 10kHz in circumstances like car traffic where both eyes and light sources are moving fast.
![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png)
timeasmymeasure
no subject
Date: 2011-07-19 12:58 am (UTC)However, an interesting proviso there is the non-moving part. If either the LED's or the person viewing them are in motion, *particularly* if the person is reading or rapidly looking from one side to the other (as you do when you drive) the safe frequency rises dramatically. There's research out there that indicates people exhibit signs consistent with eyestrain from flickering lights at strobe rates of over 10kHz in circumstances like car traffic where both eyes and light sources are moving fast.