Hi folks,

New to EET here.

Just got this LED board online, but on board are parallel sets of LED bulb and diode, the sets themselves are connected in a series (see attached pictures).


What I don't understand is: what is the role of those diodes? I thought they were there to provide an alternative path for current to flow should an LED bulb fail, but then one bulb blew up, and I got an open circuit...


Thanks in advance!

 

Reverse Current suppressor -- LED junction capacitance may be relatively "high" - in switching it may mean momentarily excessive reverse current through the LED -- which might damage it (either the LED junction stack strucuture or bonding wires) without parallel reverse protection diode and/or small capacitor that is higher than the LED-s junction capacitance ← especially important with High-Power LED-s

 

The diodes may also be for reverse voltage protection, since the LEDs that I am familiar with have rather low reverse voltage tolerance. And when you say "one blew up", was that an LED or one of the parallel diodes? That part is not clear to me.
What voltage are you supplying? and is it rectified AC or pure DC?