I am new to the amazing world of electronics and am starting out small. I think…
Early 2010, the wife and I bought a house that was built in 1979. Now I started replacing light switches and encountered something that appears to me as a weird setup.
This is a simple schematic of what I managed to figure out so far:
I know this makes no sense at all. What I try to explain is that I have 5 switches that turn on the same light. Each switch has 3 wires, a red, black and blue wire. The light bulb has 2 wires and a ground wire.
The Switches
I can't figure what kind of switches these are and I can't find the location where the yellow wire from the light bulb is connected to the hot wire.
Below is a picture I've taken from the switch.
The mechanism works like this: When the button is pushed down, I measure zeroish resistance between the top-left and the bottom connection point. Once I release it though the resistance is infinite again. All the other connections always measure infinite resistance.
Any pointers on the type of switches or how this could all work is greatly appreciated! I want to learn how all this stuff works and I have a multimeter to measure current/resistance and a lot of other things I don't know much about.
Update
Maybe I shouldn't have drawn the schema as it adds to the confusion but the point is that I have 5 switches with each having 3 wires connected. A red one, a blue one, and a black one. From what I've measured:
- Between blue and red: 230V
- Between blue and black: 230V
- Between red and black: 0V (These short circuit if you would connect them)
The button on these switches is indeed sort-of like a pushbutton. You push it down and it comes back up automatically. From what I've measured is when pushed down there is no resistance but once it's back up (released), there is again infinite resistance.
What I would like to know is how could this be done? What sort of switch is this as I have no clue. A cross switch would need four wires and I only have three.
Best Answer
You say that, when you release the button, the contact opens again (resistance goes to infinity). But the light stays on, right? That means there must be some device which has a "memory" of the last action: you push a button, the light goes on and stays on, until you press the button again (or another button). I'm sure there is a device in the cabinet (Dutch: "schakelkast") which toggles its output on every pulse it receives, and which in this way controls the lamp.
The wire on the top right of the switch also hints in this direction; it's a signal wire, it's too thin to be a power wire. My hunch is that it carries the pulses to the actual switching device (I don't know what it's called).