I think I understand. the fans are on the back panel and you have wires wining to the conections and when the back panels are on they make connection and run.
Spot on!
So.. can you explain the part where just hooking the fan up to some kind of normal switch is an issue?
It is not a switch I am trying to create, it is a connection. (I always want the fans to be turned on.)
If the wires going to the fans are plugged into the power supply they have to be unplugged before the panel can be removed. This means unscrewing the panel and while holding it, trying to remove the connection plug. To attach the panel back to the cab the process has to be repeated.
With this system there is no wiring. It is kind of like an electric slot car with the little spring loaded contact points rubbing the track and powering it as it goes.
I just put the panel back onto the cabinet and the power is returned to this panel when the layers of foil make contact.
Or maybe better , use a couple of large steel washers.
Washers were actually my first prototype! Found them difficult to hold down flush once they were wrapped in wire (had to wrap them because I couldn't get solder to stick to them). Coke can would be too thick. I am trying to solve this problem within the raised height of a t-nut which is 2mm. I should also note that to make this thickness the foil needs to be folded about 20 times so it is not one slither of foil that is carrying the 12 volts, it is more like a thick "chunk" of foil.
My test rig has now been running for just over two hours and the foil is still cold with no hot spots, it looks like heat won't be an issue. I also tried setting fire to some foil with a lighter, couldn't get it to burn which is kind of reassuring.