摘要 |
<p>The quartz controlled electric clock, with a directly driven pendulum, uses a drive with a coil and a permanent magnet, and an electrodynamic changeover system for the pendulum. Pulses to drive the pendulum are generated by an integrated circuit which incorporates the quartz oscillator and frequency divider stages to operate a polarised stepping motor. This integrated circuit and the quartz crystal are included a unit with its output connected to the pendulum driving coil. The pulses used to operate the seconds indicator are used to control each half swing of the pendulum, and applied as control signals to the coil. The time allowed for a half swing is 0.33 secs., and the time taken between two changeover pulses is one second. The frequency of the quartz oscillator is 4194304 MHz and the frequency divider has 23 divider stages.</p> |