Principle and detection method of piezoelectric diaphragm buzzer
Publish Time: 2019-07-09 Origin: Site
Piezo ceramic elements buzzer is in an ionic crystal, positive and negative ions.which are regularly arranged alternately to form a crystal lattice. This creates an intrinsic electric moment, a polarized charge appears on the surface of the piezo crystal, and because the piezo crystal is exposed to the air over time, the charge is neutralized by the alien ions in the air that fall onto the crystal face. Therefore, both the polarization surface charge and the electric moment do not appear. However, when the piezo crystal is mechanically deformed, the crystal lattice changes. Thus, the electric moment changes and the surface when polarization charges by value. Thus, the positive or negative charge on the surface has a measurable increment (increase or decrease), which is the amount of electricity produced by the piezoelectric effect.
If you exchange the test pen position and re-experiment, the order of the pointer swing is: swing to the left → return to zero → swing to the right → return to zero. Under the same pressure, the larger is the pointer swing, the highersensitivity of the diaphragm piezo element. If the pointer does not move, it indicates that the piezo buzzer is leaking or damaged inside. The capacitance of the buzzer can be directly measured by the digital capacitance meter, and the capacitance should be in the range of 0.005~0. 02∧f.