Here is my explanation of how the balance wheel and setting knob shaft interact.
When the clock has been disconnected from power for a while, the balance wheel comes to rest in its “home” position. This position is marked by a scored line on the balance wheel. Normally the balance wheel switch is closed in this position, so when power is connected to the clock, the balance wheel will rotate counter-clockwise and the balance wheel will oscillate as long as power is connected. If the switch were not closed, the balance wheel would not oscillate. Delco thoughtfully provided a way to manually apply power to the coil. Pulling out the hands setting knob closes a switch which activates the coil to start oscillation.
Edited by chevy50jim (09/03/17 04:39 PM)