• Mechanical Buzzer

    Mechanical buzzer has high resistance all the time. The DC resistance is infinite, and the AC impedance is also large. The narrow band sound generator is usually made of piezoelectric ceramic chips.A large voltage is required to drive, but the current is very small, just a few mA. The power is also very small.

    Active buzzer with internal oscillation and drive circuit. It can ring when the power is on. Like the horn, a passive buzzer can only sound with alternating audio voltage, and can also sound at different frequencies. However, the sound of the buzzer is unpleasant anyway, so the square wave is often added instead of the sine wave.


    1 What is a mechanical buzzer?

    Mechanical buzzer is a special subclass of electromagnetic buzzer, which is composed of oscillator, electromagnetic coil, magnet, shell, etc. Unlike the ordinary electromagnetic buzzer, the vibrating plate of the mechanical buzzer is installed on the housing, and its frequency is generally low, about 0.5 kHz. Generally, the frequency of the electromagnetic buzzer is about 2 kHz. Mechanical buzzer is an electronic buzzer with an integrated structure. It is powered by DC voltage and is widely used as a sound generator in computers, printers, copiers, alarms, electronic toys, automotive electronic equipment, telephones, timers and other electronic products.

    2 What is the pronunciation principle of mechanical buzzer?

    Mechanical buzzer is mainly composed of multivibrator, buzzer, impedance matching device, resonant box, shell, etc. Some piezoelectric buzzer shells are also equipped with light-emitting diodes. The multivibrator is composed of transistors or integrated circuits. When the power is turned on (1. 5~15V DC working voltage), the multivibrator starts to vibrate and outputs 1. 5~2。 For 5kHZ audio signal, the impedance matching device drives the buzzer to make sound. The buzzer is made of lead zirconate titanate or lead magnesium niobate piezoelectric ceramic material, and silver electrodes are plated on both sides of the ceramic plate. After polarization and aging treatment, the buzzer is stuck to the brass plate or stainless steel plate.

    3 The characteristic of mechanical buzzer:

    Piezoelectric buzzer has the characteristics of small size, high sensitivity, low power consumption, good reliability, low cost and good frequency characteristics. Therefore, it is widely used in alarm of various electrical products. The high-voltage electric buzzer with low cost, good frequency characteristics and sensitivity has small volume. The most common ones are music greeting cards, electronic doorbells, electronic toys and other small electronic products that can be used as sound devices, save power, have good reliability, electronic watches, sound purposes, and pocket calculators.

  • Working Principle of the buzzers

    Now that we've had a better look at Piezo and magnetic buzzers' structures, we can move on to how they actually work:

    Piezo Buzzer

    Piezo Buzzer

    Due to the piezoelectric material, when an AC is passed through it, it'll shrink and expand. This would then cause a vibration which would produce sound waves as you can see from the diagram.

    Magnetic Buzzer

    Magnetic Buzzer