Coming from a non-electrical mindset, I’ve read several Relay X1 questions on the forum here and they are doing stuff way beyond what I need.
My problem is simple, I just want to hookup a fan (for an example) to a relay and be able to control it with a button. Planning to use all GHI modules. I have the relay X1, button, and a Spider II mainboard.(and several other modules) (the fan is low amps/voltage, I checked the range that the Relay X1 docs point out) You turn the board on, the fan is off. You hit the button, the fan turns on. Hit the button again, it turns off. Pretty basic. The coding part I can figure out.
The problem is when I’m looking at the actual board, I don’t know what to hookup. I looked at the electrical diagram but I’m unfamiliar with this; being “FEZ” I was hoping someone could just tell me what wires to hookup and where. Normally I march ahead and just learn as I go, but a mistake here could cause a fire, electrocution, or something even worse.
The only docs I saw was about the relay itself which just had the diagram and not an example. There’s a few youtube videos but they don’t show how to hook it up.
Is there documentation that talks about this? If so I’ll be happy to go and read that. But after awhile of searching I could not find anything.
What version of the module do you have? And are you talking about an AC fan or a DC fan? (I’ll assume DC, as that’s all I’m comfortable giving guidance on. In Australia, to do anything with AC you must be licensed. The concepts are the same though, AC to DC).
Think of the relay as an “inline switch”. You have a “common” pole in the relay, and you have a switch element that is either connecting the common to the output or stopping it. The two positions, “normally open” and “normally closed”, just talk about the default position (when the relay isn’t energised) - for your use case, where you want the default position to be “fan off”, you will want to use the NO pole and the COMMON.
With a DC fan, you’re basically wanting to put +voltage to one wire of the fan, and GND to the other. See the left side of the image attached. Thinking about the relay as a switch, you can choose one of the wires to switch - you can switch the “high side”, so that the +V never reaches the fan, or you can switch the “low side”, so that the +V never has a return path to the power supply. They have safety implications, but since this is DC, it doesn’t really matter which you choose - use high-side switching if you get the choice. So this means you’ll be “breaking” the wire running to the fan; see the right side image. This way the power won’t reach the fan until the relay is closed.
Thank you both very much for the help, yes it is a DC fan. And It is a very inexpensive fan, used just for an example. I’m going to hook up a nice fan to it when I know if all works.
Your description is great…I have a technical mind but get caught up with circuit diagrams. I’m going to look for a class around here to finally learn it.
I wasn’t sure what posts to hook up to the wires, but I understood it was going to be an in-line switch from the start. I have enough info to be dangerous I think, but I’ll be very careful.
Both diagrams helped because one refers to the symbols and the other has the letters which is in the diagram,