Thread: Do switch mode power supplies flicker in time with mains?
View Single Post
  #12   Report Post  
Posted to alt.home.repair
bubba bubba is offline
external usenet poster
  
Posts: 16
Default Do switch mode power supplies flicker in time with mains?
On 12/19/18 9:22 AM, wrote:
In this case they will NOT be in sync. Switching power supplies are usually free running and the frequency will be drifting around. Even if they are the same model, component tolerances and temperature variations will mean they are on slightly different frequencies and there will be no defined phase relationship.

mark

Correct. My strings of cheapo imported LED Christmas lights appear to the naked eye to be on 100%.

However, when viewed through my cheapo webcam, they appear on for 5 seconds, fade to off 2 seconds, off for 5 seconds, fade to on 2 seconds, lather/rinse/repeat.
Reply With QuoteReply With Quote