So today I’m learning about 3 way switches. Mostly out of necessity, because I hosed 2 three way switches in our house by putting in single pole switches. I knew I was doing it,… just wanted to see if I know how they worked, I don’t and what I did failed 😛
Problem is, I couldn’t visualize how it worked, I need to visualize something before I understand it, at least, that seems to be the easiest way for me to figure something out. Here is a great youtube vid that provides an excellent simple diagram about it:
Basically, with AC, you don’t really have positively and negatively charged wires, what you have is one wire that is considered HOT and the other,… well cold I guess. One has current, the other does not. With switches for lights and other such items, you’re basically completing the circuit. The light bulb wants a round path, from electricity source and to the electricity source, power comes out of the wall, through the light bulb, the light you see is the resistance in the tiny bulb wire that is heating up and emitting infrared heat, visible light spectrum emissions obviously as well. So the switch in that mix is just a cut so to speak in the path to the light. Or from the light, I guess it doesn’t matter, but there are specific colour conventions for such things. Black is hot, white is cold. Anywho you complete the circuit by flipping the switch into the ON position, which in behind just connects the black and the white wire together basically.
Now, so you have your basic theory down, … the 3 way takes it up a notch and provides an alternate path for the electricity to flow, so there are 2 potential circuits to the bulb, each switch cuts and establishes power to one or the other wires on the ‘cold’ side of the switch. When both lights match, the circuit is complete and the light glows (one note is that I”m talking about incandescent bulbs…google it if you don’t know what that means.. How fluorescent ones work is a bit different, not based on resistance directly.)
Anyways, the vid explains it well and gives me a picture I can use in my head to trouble shoot our many 3 way switches.
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