Views:1 Author:Site Editor Publish Time: 2019-12-24 Origin:Site
The function of the piezo ceramic crystal inductor is mainly to transmit DC and block AC. It mainly plays the role of filtering, oscillation, delay and notch in the circuit. It is inductive coils block AC current. The size of the blocking effect is called inductive reactance x1, and the unit is ohms. Its relationship with the inductance L and AC frequency F is x1 = 2πf1. Inductors can be divided into high-frequency current blocking coils and low-frequency current blocking coils. Tuning and frequency selection: The LC coil is formed by the inductor and capacitor connected in parallel. That is, if the natural oscillation frequency F0 of the circuit is equal to the frequency f of the non-AC signal, the inductive and capacitive reactances of the circuit are also equal, so the electromagnetic energy oscillates back and forth in the inductance and capacitance, which is a resonance phenomenon of the LC circuit. During resonance frequency, the inductive reactance and capacitive reactance of the circuit are equal or opposite to each other, the inductive reactance of the total current of the circuit is the smallest, and the amount of current is the largest AC signal.
The performance indicators of piezoelectric ceramic transducer are as follows:
(1) free dielectric constant / E0: 1000-6000;
(2) Dielectric loss and (2-12) '10-3;
(3) Piezoelectric strain coefficient d33: 300 ~ 600 PC / n;
(4) Plane electromechanical coupling coefficient KP: 0.56 to 0.70;
(5) Mechanical quality factor QM: 100 ~ 2000;
(6) Curie temperature Tc: 280 ~ 400 ℃.
Equipment requirements: ball mill, spray granulator, automatic tablet press, sintering furnace, electrode infiltration furnace, polarization high voltage device, impedance spectrometer, d33 quasi-static tester.
The conductivity of the conductive coating of the piezo ceramic disc is mainly related to the conductivity, content, particle size and compatibility of the polymer and filler particles. The finer the carbon black particles, the closer the network chains are packed, and the larger the specific surface area. The more mass particles there are, the more advantageous it is to form a chain-like conductive structure in the matrix. Under certain other conditions, the dispersion of carbon black particles in the polymer will determine the conductivity of the conductive coating. When the carbon black particles reach the nanometer level, the specific surface area is very large, and flocculation easily occurs during the preparation of the coating. The coupling agent will significantly affect the dispersibility and wetting of the filler in the matrix. Therefore, it is necessary to study different coupling agents effect on the conductive properties of the coating. In addition, carbon-based composite conductive coatings are prone to cracking during film formation, which leads to poor conductive stability and affects the application of the coating. One of the effective treatment methods is to add a coupling agent. Therefore, the application of the coupling agent will directly determine the conductivity of the carbon-based composite conductive coating.