We have a need for continuous power and made a couple of videos showing how the circuit board was made. We machined it rather than using FeCl.
What does it do?
This is a circuit to provide redundant power. 2 input power supplies are connected to the board. The active component, circuit, selects the one with higher voltage. If the higher voltage supply fails (e.g. unplugged), power input is immediately switched to the lower voltage supply. If the lower voltage supply fails, no switching occurs, and the device remains powered.
But why we need it?
If our robot is powered down, it will take an hour to re-establish the extremely accurate positioning we require. We can now switch from power brick to battery to new battery to brick without losing positioning.