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The piezoelectric buzzer mainly consists of a multi-harmonic oscillator1. Piezoelectric buzzer Piezoelectric buzzer is mainly composed of multi-harmonic oscillator, piezoelectric buzzer, impedance matching device and resonance box, shell, etc.. Some piezoelectric buzzers are also equipped with light-emitting diodes on the shell. The multi-harmonic oscillator is composed of transistors or integrated circuits. When the power supply is turned on (1.5~15V DC working voltage), the multi-harmonic oscillator is activated and outputs 1.5~2.5kHZ audio signal, and the impedance matcher pushes the piezoelectric buzzer to make sound. The piezoelectric buzzer is made of lead zirconate titanate or lead niobate piezoelectric ceramic material. Both sides of the ceramic sheet are plated with silver electrodes, polarized and aged, and then glued together with brass or stainless steel sheets. 2. The piezoelectric buzzer is composed of oscillator, electromagnetic coil, magnet, vibration diaphragm and shell.
Buzzer (1) Preparation of electromagnet M: in the length of about 6 cm iron bolt around 100 turns of wire, the end of the line left 5 cm for the lead, with transparent tape to stick the coil to avoid loosening the coil, and then tape it to a box, the electromagnet is ready. (2) prepare the shrapnel P: cut a long iron sheet about 2 cm wide from a tin can box, bend it at right angles, connect one of the leads of the electromagnet to the shrapnel, and then tape the shrapnel tightly to the board. (3) Use a crank pin to make the contact Q, use the book to crank pin pad high, with tape, lead a wire, as shown in the diagram to connect the circuit. (4) adjust the distance between M and P (by moving the box), so that the electromagnet can attract the shrapnel, adjust the distance between the contacts and the shrapnel so that they can be exactly in contact, and the beeping sound can be heard after the power is applied. |
