I have noticed that about half of the LED Christmas light strings have a "l ump" about 1.5 inches long and 1/2 inch diameter in series with the lights, which have polarized sockets. I assume that it must either be a diode or a resistor or perhaps both. What puzzles me is what limits current and pol arizes the AC into pulsating DC in the light strings that do not have any v isible "lump"? Perhaps there are resistors built into each individual lamp , but the lamps that I have taken loose have the LED leads going directly o ut the bottom of the socket. And, I haven't seen any sign of any resistors built into the sockets themselves.
Anyone know for sure what's going on???