Electric Parts of Christmas Lights
When it comes that time of year when you have to take out all the old boxes full of Christmas lights and check if they still work, it can turn out very useful to know how o perform some simple repairs on order to save entire strings of lights.
The incandescent bulbs, the oldest and most used Christmas light invented by Thomas Edison, are wired with positive and negative wires creating a series of small bulbs through which current passes.
Not for a long time LED lights have been used to create Christmas light, even though they have been used since 1960.
There is an institution called Underwriters Laboratories with the purpose to say if the Christmas lights are for indoor use or outdoor use. The UL standards require that a set of Christmas lights should have a pair of fuses already installed in order to prevent fires, melting and overloading.
There are also Christmas lights designed to work continuously even if one of the bulbs burns out or is missing but these are more expensive. The main advantage of this technology is to save you the hard time searching for the bulb that stopped working. Each bulb has a back-up power supply provided by a redundant positive wire that runs through the system.