Tower clock structure generally has mechanical type and electromechanical type two kinds.The mechanical tower clock takes the heavy hammer as the power source, drives the walking mechanism to indicate the time through the mechanical transmission, and strikes the specially cast "clock" to tell the time.This kind of tower clock has a large structure and poor accuracy, and only exists in the old buildings. The needle running system of electromechanical tower clock is mechanical, and the control system is in the form of child and mother clock.Tower clock is a sub-clock, it receives the high-precision mother clock regularly issued by the electrical pulse signal, by stepping (or synchronous) motor driving needle mechanism indicating time, and the mother clock synchronized operation.A bell or music that tells the time is emitted by a tape-recording or programmed control.
