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Overview of Buzzer

Updated: Mar 22


A beeper, buzzer, or other auditory signaling device can be mechanical, piezoelectric, or electromechanical in nature. This is mostly used to transform the audio signal into sound. It is often powered by DC voltage and is found in computers, printers, alarm clocks, timers, and other devices. It may produce a variety of sounds, including alarms, music, bells, and sirens, according to the varied designs.

Positive and negative pins are the two that are included. This can have a longer terminal or the '+' sign to indicate its positive termination. This terminal draws power from six volts, whereas the negative terminal, which is linked to the ground wire, is denoted by the short terminal or the sign '-'.

Types of Buzzer


As the name implies, the piezoelectric type vibrates and produces sound on the metal plate by means of the piezoelectric effect and pulse current of the piezoelectric ceramic. Resonance boxes, multiple resonators, piezoelectric plates, housing, impedance matchers, and other components are used to make this type of buzzer. LEDs are also included into the design of some buzzers.

Transistors and Integrated circuits make up the bulk of this multi-resonator. This resonator will oscillate and produce an audio signal at 1.5 to 2kHz as soon as it receives power. The piezoelectric plate will be forced to make sound by the impedance matcher.


A magnet, solenoid coil, oscillator, housing, vibration diaphragm, and magnet are the components used to make this kind of buzzer. When the power source is turned on, the oscillator that generates the audio signal will start to send current through the solenoid coil, creating a magnetic field.

Under the influence of the magnet and solenoid coil, the vibration diaphragm will occasionally vibrate and produce sound. Its frequency range is between 2 kHz and 4 kHz.


The components utilized in these buzzer types are identical because they are subtypes of electromagnetic buzzers. However, the most notable distinction is that the buzzer is now external rather than internal.


An electromagnet and a bare metal disk may be used to construct these kinds of buzzers. This operates on a similar concept to electromagnetic and magnetic fields. It produces sound as the disc moves and becomes magnetized.


Similar to a piezo type, a magnetic type similarly produces sound; however their fundamental functions distinguish them. Because the magnetic type operates via a magnetic field, it is more fixed than the piezo type.

Magnetic buzzers create a magnetic field by using an electric charge rather than piezo materials. This allows a different component of the buzzer to vibrate and produce sound.

The uses of magnetic buzzers are comparable to those of piezo alarms used in watches, clocks, and keyboards, among other household appliances.

Buzzer Usage

An effective way to add sound elements to our system or project is to use a buzzer. It is a very compact and sturdy two-pin gadget, so using it on a breadboard or PCB is easy. Therefore, this component is frequently utilized in most applications.

Buzzers come in two primary varieties: premade and simple. A basic kind will continually emit beeps once it is powered on. A prefabricated kind emits a beep and seems heavier. Beep. Beep. Its internal oscillating circuit produces this sound.

A DC power source with a voltage range of 4V to 9V is used by this buzzer. Although a regulated +5V/+6V DC source is recommended, this may be operated with a 9V battery. In order to turn the buzzer ON or OFF at the appropriate interval, it is often connected via a switching circuit.

Working principle of a buzzer with a circuit diagram

The water level indicator circuit schematic with buzzer is displayed above. The water level in a tank, washing machine, pool, etc. is sensed or detected using this circuit. A transistor, buzzer, 300K variable resistor, power supply, and 9V battery are among the few parts that make up this easy-to-design circuit.

When the circuit's two probes are inserted into the tank, the water level is detected. A buzzer attached to the circuit emits a beep sound when the water level rises above the specified level. The 2N3904/2N2222 NPN transistor used in this circuit can be replaced with any general-purpose transistor. However, the circuit employs a BC547B NPN transistor.

The transistor utilized in this water level sensor circuit functions as a switch, making it a relatively easy circuit to operate. When the two sensors detect the water level in the tank, the transistor switches on, and electricity starts to flow through it, causing the buzzer to sound.


Industrial Settings:

Buzzers are commonly employed in industrial environments to signal alarms, warnings, or specific events. Their reliability and effectiveness make them essential for notifying workers about potential hazards or operational changes.

Electronic Devices:

Many electronic devices incorporate buzzer modules to provide audible feedback. For example, in household appliances like washing machines or microwave ovens, a buzzer sound signals the end of a cycle.

Security Systems:

Buzzer alarms play a vital role in security systems, alerting individuals to unauthorized access or potential threats. The distinct sound they emit ensures immediate attention.

Automotive Sector:

In automobiles, buzzers are utilized to signal various conditions, such as a door ajar, low fuel, or a seatbelt reminder. The attention-grabbing buzzer sound serves as an effective means of communication.

Educational Applications:

Buzzers are also commonly used in educational settings, particularly in quiz games or electronic learning aids. Their sharp sound serves to capture attention and indicate correct or incorrect responses.

The buzzer sound varies depending on the design and purpose of the device. It can range from a simple continuous tone to more complex patterns, such as intermittent beeping. This versatility in sound production allows for customization to suit specific applications.


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