"a power source coupled to the control circuitry for supplying electrical power to the device"

The problem in reading that phrase is the direction of the circuit that is being defined...looking backed at the micro controller/MOSFETS....or out to the device issues. You do not get a complete circuit until the microcontroller issues allow the power source to flow.

More simply.....there's a fence.....the power source of that phrase is the fence. The micro controller issues are on one side and all device issues are on the other.

control circuitry = Micro controller.....as depicted and explained in the body of the patent.

doni