Abstract: An energy source forming a gravity pendulum clock, including a train of clock gears, includes a fixed position generator having its axle of rotation secured to an axle of rotation of at least one gear of the chain of clock gears; output leads from the generator, the leads comprising an input to a device to be powered; a fixed position solenoid in magnetic communication with a ferromagnetic element; and output leads from the solenoid, the leads defining an input to the device to be powered.