Jump to content
Light-O-Rama Forums

Does dimming LEDs add flicker?


Recommended Posts

I currently do not use LEDs in my display, and I understand that full-wave LEDs eliminate/reduce the strobing that you see in half-wave sets.  It is my understanding that this is accomplished basically by doubling the duty-cycle using a bridge rectifier.  My question is though, if you dim these full wave strings, does the flicker effect return, as that is simply reducing the duty-cycle, no?

Restated, is there a visible difference between a half-wave set at 100% intensity and a full-wave set at 50% intensity?


Link to comment
Share on other sites

cTb  Triac (also used in many wall dimmers) pulses at the same Line duty cycle.  The reason flicker was not as much an issue with incans, was the filament took time to cool or heat

cMb MosFet (used on DC controllers) More like a variable resistance

So back to your Q. Full wave fed LEDS get their power 120 times vs 1/2 wave at 60. The results still depends on the actual LED

Edited by TheDucks
Link to comment
Share on other sites

Half wave LEDs flicker at 60 times per second (50 in Europe). Some people can notice this, but not when looking at them directly. Full wave LEDs flicker at 120 times per second, which is too fast for the human eye to notice.

CMB (DC) boards use pulse width modulation, which technically also makes the LEDs flicker, but at 400Hz.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...