Why don't your Christmas lights work? Sadly ... this is a great time to look at the difference between series and parallel circuits. A Simple Circuit Just about the simplest circuit you can ...

which means the entire string of Christmas lights will go out. Some of these could be replaced with a working bulb, but not all. The other type of circuit light strands use is a parallel circuit.

Getting into the spirit of Christmas might mean early gift ... all the lights after that burn out, too. Each light on a parallel circuit is powered by its own circuit, so if a light burns out ...

Got a strand of Christmas lights that just won't ... each bulb has its own source of current. If you have lights with a parallel circuit (if they're LED, they have a parallel circuit for sure ...