said by TheMG:
Actually, half-wave rectified LEDs will "flicker" at 60Hz.
Full-wave rectified LEDs will also "flicker", but at 120Hz, which makes it much less noticeable.
Toss in a capacitor and now you've eliminated the flickering entirely.
Unfortunately, it seems that manufacturers of LED light strings don't find the cost-benefit ratio worth it, even though we're talking about pennies worth of extra parts.
Not sure what I was thinking on the frequency. I'd just finished getting zapped by a phone ringer circuit that I think is 20 Hz so maybe that confused me as it did hurt a little bit!
I was talking about building a filtered rectifier circuit but failed to mention the need for a cap or two depending on what you have laying around.
I used lytics pulled from switching power supplies such as the kind found in today's HDTV power supplies. Those usually have a decent voltage rating as well as a high enough capacitance value so they filter very well. I could fit the assembly into a extra deep handy box along with a duplex receptacle.
The cap(s) and rectifier and fuse(s) would fit under the receptacle as long as I found the right caps.
Some of the caps rated for 350 volts or higher can get pretty large in physical size depending on how they were designed to fit the application they were used in!