Balance-spiral oscillation frequency control device for quartz-crystal watch, has stepping motor to which error signal is applied to correct position of regulator index such that precision of watch is same as that of received time signal

摘要

The device has a bidirectional stepping motor placed between a plate and a dial of a horological movement. An error signal is obtained by comparing a real time provided by an external reference time signal with a time indicated by the movement based on counting of oscillation of an assembly of a balance (3) and a spiral (4) of the movement. The error signal is applied to the stepping motor to correct position of a regulator index (6) through a reduction gear train and by a regulator (5) such that precision of a watch in duration is same as that of the received time signal.