How Everything Works
How Everything Works How Everything Works

Question 922

What is an analog clock? How do you attach it to batteries? — HB
An "analog" clock is a clock that has an hour hand and a minute hand. Twenty years ago, virtually all clocks were analog clocks but nowadays electronics has made it easier to display time with digits ("digital" clocks) than with hands ("analog" clocks). However, there are some clocks and wristwatches that still use moving mechanical hands to display the time. Most of these devices use quartz crystal oscillators to control electronic pulsing devices that drive electric motors that advance the hands. In such clocks, the batteries power the oscillators and the motors. You connect them as you would any electronic device: you form a string of batteries with the correct voltage, attach the negative lead from the clock to the negative terminal of the battery string, and attach the positive lead from the clock to the positive terminal of the battery string.

There are also some analog clocks in which the hands are just lines on a computer display, an arrangement that strikes me as silly. Finally, long ago there were two interesting types of analog electric clocks: the electric clocks that used the AC power line to run synchronous electric motors to advance their hands and the electric clocks that were used in automobiles. The automobile clocks were actually mechanical clocks, with mainsprings and everything, but they were wound by electromagnetic devices. Every minute or two, this device would give the spring a small wind and you would hear a click.


Copyright 1997-2017 © Louis A. Bloomfield, All Rights Reserved
Privacy Policy