Why Does an Entire String of Christmas Lights Fail When a Single Bulb Burns Out?
A seemingly innocent string of Christmas lights actually has many tricks up its sleeve, most of which won’t be discovered by the household tree decorator until it’s too late. Christmas tree lights really do multiply in the box, and they spend most of their days braiding themselves together in Gordian knots. The final act of Christmas light cruelty is the “all or nothing” lighting trick. Depending on the design, an entire string of Christmas lights can indeed fail if only a single bulb burns out or comes out of its socket. The reason for this has to do with the nature of electrical circuits and the Christmas bulbs which depend on them. There are two basic electrical wiring scheme used to form a string of Christmas lights. One scheme, called a series uses a single wire connection between bulbs to light them all. The electricity from the household outlet flows down that single wire and through the first Christmas tree bulb. That bulb glows as a certain amount of electrons escape into the
