You said "LED flicker usually has nothing to do with AC power." But most LED lighting flicker is the result of using a capacitive dropper power supply. These ar

You said "LED flicker usually has nothing to do with AC power." But most LED lighting flicker is the result of using a capacitive dropper power supply. These are cheap and efficient, but produce a lot of ripple at double the line frequency (with full-wave rectification). Filtering the output enough to make flicker imperceptible would cost more, and not everybody notices the flicker so it's easy to get away with cutting corners. See: http://www.bigclive.com/ledlmp.htm http://www.bigclive.com/ledlmp.htm Better and more expensive LED drivers use a switch mode power supply, which does not produce visible flicker.