Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

LED's and a single rectifier

  1. Apr 13, 2010 #1
    If an LED is connected to a single rectifier, resulting in a half wave, will this cause the LED to pulsate?!
    I no a bridge-rectifier will work and is more efficient to keep the LED constantly on but can a single rectifier work???
  2. jcsd
  3. Apr 13, 2010 #2


    User Avatar
    Science Advisor

    Yes, it does pulsate, but it is still at 60 Hz so you can't see it. A bridge or full wave rectifier gives 120 Hz from a 60 Hz supply.

    You can add a capacitor across the output of the rectifier and get a steady DC voltage. This is worth doing and results in brighter output.

    Without the capacitor (maybe 1000 uF) the LED has to get high current pulses to appear bright.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook