Electronic control timepiece

摘要

A compact and thin electronic control timepiece having a long duration time for indicating highly accurate time. The flow of an AC electromotive force induced in a coil in a generator powered by a power spring is supplied to a step-up circuit in an IC. The step-up circuit boosts the rectified electromotive force doubling to charge in a smoothing capacitor as storage power. A step-up control circuit generates a step-up control signal for controlling the step-up operation of the step-up circuit. A cycle comparing circuit compares a reference cycle signal from an oscillation circuit and a detected cycle signal synchronized with the rotational cycle of the generator, generates a cycle correction signal for eliminating a time difference between both signals, and outputs the signal to a load control circuit. The load control circuit in turn changes a load current on the generator by appropriately selecting a load resistor for changing switching elements within an internal circuit, controls the amount of an electromagnetic brake corresponding to a current amount flowing through the load resister and thereby governs the speed of the rotation cycle of the generator.