It works, but I don't know how

[Fred Bear]

Thanks to all those responding to my question about wiring up Atlas switches to a manual switch as well as the AIU. It does work, but how? The manual switch would appear to block at least the ground from completing the circuit. I guess if it works I should be happy, but I'd like to understand the thing as well! Jake

[willpick]

Jake, the Atlas pushbutton switch is an odd setup. The three posts on the top are the ones that go to the switch machine: Hot side (coil 1); common; Hot side(coil 2). The posts on the left and right sides are the power connections: top is common, connected to the center post and the right side power post of the pushbutton. The connection on the bottom left is the hot, which connects to the right side bottom post.  Atlas provides the jumpers so that you can "daisy chain" all of the buttons.   Please excuse my poor explanation-- I'm working from memory--

The way the pushbutton operates is to momentarily connect the "hot" to the coil- left or right-- it's got a leaf spring contact that bends down to contact the "hot" power. The common is always connected.

[Fred Bear]

Pretty darn clear explanation to me! Now I understand why the AIU can still work. I was thinking the common was robbed until the Atlas switch button was pushed. The hot side is provided by the AIU itself, so that was not a problem. The AIU is basically just a switch, three inputs/outputs, one providing the power, the other two are the sides that get switched. Jake