Quartz Clocks

In 1927 the first quartz clock marked the beginning of the end for mechanical clocks as a primary time piece for the average person. Today they are found everywhere and are cheap to produce.

The quartz clock works by using a crystal oscillator. Silicon dioxide crystals are piezoelectric and are also used as microphones and speakers (Unit 4). When you pass electricity through quartz it vibrates (oscillates) at a specific frequency that does not change much with temperature. When you place this in an amplifier circuit you can create a steady “sound”. The frequency of oscillation depends on the way the crystal is cut and the placement of electrodes on it. The standard quartz watch is set to a standard of 32,728 Hz (above human hearing range). A binary digital counter is attached to the device and is designed to overflow once each second, this creates a digital pulse at each second, and this is the basis of the quartz clock.