Quartz clock principle

2021-08-03 23:53

Quartz clock principle

The core of the quartz crystal sensor is the sensing element - a piezoelectric quartz wafer. The working principle is the piezoelectric effect, that is, after the quartz crystal is subjected to mechanical stress in some directions, an electric dipole is generated. On the contrary, if a voltage is applied in a certain direction of quartz, deformation occurs in a specific direction. The phenomenon is called the inverse piezoelectric effect. If an alternating electric field is applied to the quartz crystal, the crystal lattice will generate mechanical vibration. When the frequency of the applied electric field coincides with the natural oscillation frequency of the crystal, the resonance of the crystal occurs. Since the intensity of the electric field produced by the quartz crystal under pressure is small, deformation is only required by a weak applied electric field, which makes the piezoelectric quartz crystal easily resonate under the application of an alternating electric field excitation. The oscillation energy loss is small and the oscillation frequency is extremely stable. These, combined with the excellent mechanical, electrical and chemical stability of quartz, have made it a frequency reference component related to digital circuits such as quartz clocks, electronic watches, telephones, televisions, computers, etc. since the 1940s.

An interesting feature of quartz crystals is that when a positive current is introduced on one side and a negative current is introduced on the other side, the negative current side is contracted and bent into a U shape. If the positive and negative currents are introduced alternately on both sides of the quartz crystal at regular intervals, the quartz crystal will oscillate. Quartz crystals are timed according to this oscillation. The built-in quartz crystal of the personal computer oscillates 14.31 million 8180 times per second. The working principle of the quartz clock is like this.

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