Inside of a wall clock ( measurement of voltage waveform across the coil and the oscillator ) 

In this video I open the driver of a wall clock and show you the mechanical and electrical construction of the driver. I have measured the voltage waveform of the coil and across the quartz oscillator. the motor is cleverly designed and every half pulse moves the rotor half a turn. The single-tick-per-second clock has one positive and one negative pulse per second. The seemly continues operated clock has 8 cycles (positive and negative pulses) per seconds. When the battery voltage drops down to ~1 Volt, the clock stops working and that is because it does not get enough energy to reach finalize the each half turn.

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