Crystal Oscillators are the Time Base on a wristwatch or a home clock, analog or digital, Mechanical clocks have become rare due to the Maintenance and Accuracy. Some crystals can change dimensions on a electric force, some generate electricity on Mechanical Strain.
Ceramic Resonators – “The ceramic components are made of high stability piezoelectric ceramics that functions as a mechanical resonator. The frequency is primary adjusted by the size and thickness of the ceramic element.”
In the mechanical gramophone a metal needle and a horn would amplify the sound. When Record players came, the use of magnetic pickups made the needle size a bit smaller but the signal was weak. The crystal type pickups made the needle thinner and the electricity generated by crystal moving on the grooves was large, in mV. A preamp was rarely required. But Equalization preprocessing of audio was needed, to match the ear response. The electric gramophone made LP or Long Playing Record Players possible. It is analogous to DVD having more capacity than CDROM.
Crystals and Their Applications
Introduction to Quartz Frequency Standards – More than one billion quartz crystal oscillators are produced annually for applications ranging from inexpensive watches and clocks to radio navigation and spacecraft tracking systems.
Crystal Oscillator Tutorial Articles – Types of Crystals and oscillators, Frequency and relationship with Temperature, Aging and Stability of the clock.
Technical Literature – Frequency Electronics Inc. – New discoveries, research and development information, and scholarly works from some of the engineers and scientists in the FEI family,