What Is An Electromagnetic Buzzer?

The internal structure of the electromagnetic buzzer
Electromagnetic buzzer, mainly composed of iron core, coil, magnetic ring, diaphragm, PCB assembly (PCB is passive and active, active includes oscillation circuit), shell.
Iron core: divided into stamping and die-casting two processes, the material is iron nickel plating. The reason for choosing iron is that the magnetic conductivity effect is good, and nickel plating is used to achieve the purpose of rust prevention. The iron core mainly plays the role of supporting the PCB, magnetic conduction and controlling the gap in the buzzer, so the height dimensional accuracy requirements for the iron core are relatively high, and the general tolerance is controlled at ±0.01mm;
Coil: self-adhesive enameled copper wire is adopted, and the number of turns of the coil is controlled by the microcomputer winding machine to achieve the effect of self-adhesive fixation through alcohol. The wire diameter used in this industry is 0.03~0.09mm. The coil mainly plays the role of generating electromagnetic field and current limiting in the buzzer;
Magnetic ring: ferrite magnetic ring, constant magnetic field. In the buzzer, it mainly plays the role of superimposing with the electromagnetic field to make the diaphragm vibrate;
Diaphragm: Using iron-nickel alloy material, it is composed of two large and small pieces connected by strong current spot welding, and mainly plays the role of vibration source in the buzzer. Usually the frequency is adjusted by a small diaphragm, the thicker the small diaphragm, the lower the frequency, the thinner the higher the frequency;
PCB: epoxy copper-clad single panel, in the passive buzzer mainly plays a fixed lead to connect the fixed enameled wire and wire or pin, and the active buzzer has more oscillation unit;
Shell: generally injection molding by ABS, PPO, LCP, PBT materials, and different temperature-resistant materials are selected according to the customer's welding method. In the buzzer, it mainly plays the role of protection and amplification of all components.