Can a Single Rectifier Keep an LED Constantly On?

[tobi101]

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?
thanks

 

[vk6kro]

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.