Buzzing with Excitement: Exploring the Versatility and Power of Buzzers!

What is the Sound?

The vibrations that move in the air or other environment are called sound. When these vibrations reach the ears of humans or animals, They become audible.

What is a Buzzer?

A buzzer is an electrical device that produces a continuous or intermittent buzzing sound. It typically consists of an electromechanical component called a buzzer element, which is made up of a coil of wire and a metal diaphragm. When an electric current is passed through the coil, it creates a magnetic field that causes the diaphragm to vibrate, producing sound waves that create a buzzing sound.

Buzzer elements are commonly used in electronic devices, such as alarm clocks, timers, and game show buzzers, to provide an audible alert or signal. They can also be found in industrial applications, such as in manufacturing and automation, to indicate the completion of a process or warn of an error or malfunction.

Fig 1. A piezo buzzer with continuous/Intermittent sound

Buzzer Internal Parts

The internal parts of a buzzer can vary depending on the specific type of buzzer, but the most common type of buzzer consists of the following components:

1.Buzzer Element

The buzzer element is the heart of the buzzer and is responsible for producing the sound. It typically consists of a coil of wire and a metal diaphragm.

2.Housing

The housing is the outer shell of the buzzer and is usually made of plastic or metal. It protects the internal components and helps to direct the sound produced by the buzzer element.

3.Contact Springs

The contact springs are used to make an electrical connection between the buzzer element and the circuit board. They allow the buzzer to be easily connected and disconnected from the circuit board.

4.Drive Circuit

The drive circuit provides the electrical current necessary to power the buzzer element. It typically consists of a transistor or an integrated circuit that is controlled by a microcontroller or other electronic device.

5.Feedback Circuit

The feedback circuit is used to provide a signal to the microcontroller or other electronic device to indicate that the buzzer is operating correctly. It typically consists of a resistor and a capacitor that are connected in series with the buzzer element.

How does the buzzer work?

A buzzer is an electrical device that works by using an electromechanical component called a buzzer element to produce a continuous or intermittent buzzing sound. The buzzer element typically consists of a coil of wire and a metal diaphragm.

When an electric current is passed through the coil of wire, it creates a magnetic field that causes the metal diaphragm to vibrate. The vibration of the diaphragm produces sound waves that create a buzzing sound.

The electric current that powers the buzzer element is usually provided by a drive circuit, which consists of a transistor or an integrated circuit that is controlled by a microcontroller or other electronic device.

The feedback circuit is used to provide a signal to the microcontroller or other electronic device to indicate that the buzzer is operating correctly. It typically consists of a resistor and a capacitor that are connected in series with the buzzer element.

Buzzer Applications

Buzzers have a wide range of uses in various applications, including:

1.Alarm Systems

Buzzers are commonly used in alarm systems, such as smoke detectors and burglar alarms, to provide an audible warning to occupants of a building in case of an emergency.

2.Timing Devices

Buzzers are often used in timing devices, such as timers, stopwatches, and clocks, to signal the completion of a set time interval.

3.Games

Buzzers are commonly used in game shows and trivia games to signal a player's response or to indicate the end of a round.

4.Industrial Applications

Buzzers are widely used in industrial applications, such as in manufacturing and automation, to indicate the completion of a process or to warn of an error or malfunction.

5.Doorbells

Buzzers are often used as doorbells, providing an audible signal when someone rings the bell.

6.Medical Devices

Buzzers are used in medical devices, such as insulin pumps and infusion pumps, to signal various alerts and alarms.

7.Communication Devices

Buzzers are used in various communication devices, such as two-way radios, to signal the end of a transmission or to indicate a low battery level.

These are just a few examples of the many applications of buzzers. Buzzers are versatile devices that can be used wherever an audible signal is needed to indicate an event or condition.

Where to Use the Buzzer?

Buzzers can be used in a wide range of applications where an audible signal is needed to indicate an event or condition. Here are some common places where buzzers can be used:

1.Homes

Buzzers can be used as doorbells or in-home alarm systems to provide an audible warning in case of an emergency.

2.Offices

Buzzers can be used in offices for various purposes, such as timing devices and communication devices.

3.Industrial Settings

Buzzers are widely used in industrial settings, such as in manufacturing and automation, to indicate the completion of a process or to warn of an error or malfunction.

4.Public Places

Buzzers are often used in public places, such as in transportation systems, to provide an audible warning to passengers.

5.Medical Facilities

Buzzers are used in medical facilities, such as hospitals and clinics, to signal various alerts and alarms.

6.Entertainment

Buzzers are commonly used in game shows, quiz games, and other entertainment applications to indicate a player's response or to signal the end of a round.

7.Educational Settings

Buzzers are often used in educational settings, such as in classrooms and quiz competitions, to indicate a correct or incorrect answer.

These are just a few examples of the many places where buzzers can be used. Buzzers are versatile devices that can be used in many different settings where an audible signal is needed to indicate an event or condition.

buzzer Symbol in the Circuit

The buzzer works with DC voltage. The value of this voltage can be 6, 12, or 24 volts, depending on the type of buzzer. When the DC voltage is applied to the input pins, it is converted into an AC signal through an oscillator that includes resistors and transistors. The amplitude of this signal is amplified through the inductor. After that, the signal is transferred to the piezo ceramic and vibrates, which causes the sound to form. The buzzer oscillates because the transistor turns on and off over and over again. This is different from the way the inductor and capacitor oscillate.

Fig 2. Buzzer circuit

More precisely, when the DC voltage is applied, the transistor is turned on, and the voltage is transferred to the large piezoceramic connector through the coil. On the other hand, the internal (small) piezoelectric connector grounds the base of the transistor and turns it off. When the transistor is turned off, the piezoceramic voltage is cut off. The base of the transistor is grounded again, and the transistor is turned on again. This cycle continues. By doing this, an oscillating signal is generated to start the piezoceramic. The coil boosts the signal in the collector, which is then sent to the piezoceramic. This gives the piezoceramic the energy it needs to vibrate and make a sound. The small piezoceramic connector acts as feedback that doesn't stop the oscillation.

What are the Types of Buzzers?

There are several types of buzzers available, each with its unique features and applications. Here are some common types of buzzers:

Piezo Buzzers

Piezo buzzers use a piezoelectric element to produce sound. They are small, lightweight, and consume very little power. They are often used in low-power applications, such as in consumer electronics and home appliances. The piezoelectric buzzer uses the effect of piezoelectric ceramics and pulse current to vibrate the metal plate, which produces sound. The main parts of a piezoelectric buzzer are multiple resonators, piezoelectric plates, impedance matching, a resonance box, a housing, and so on. Some piezoelectric buzzers have light-emitting diodes. Multiple resonators are composed of transistors or integrated circuits. When the power supply is on (working voltage 1.5–15V DC), the multi-resonator oscillates, and an analog audio signal of 1.5–2.5KHz is output. The impedance matcher compresses the piezoelectric plate to produce sound. The piezoelectric plate is made of lead zirconate piezoelectric ceramic or lead magnesium niobate, and silver electrodes are plated on both sides of the ceramic plate.

Fig 3. Piezo buzzers elements

Magnetic Buzzers

Magnetic buzzers use an electromagnet to produce sound. They are often larger than piezo buzzers and consume more power. They are commonly used in industrial applications, such as alarms and signal indicators.

An oscillator, an electric coil, a magnet, a vibrating diaphragm, a housing, and other parts make up the electromagnetic buzzer. When the power supply is turned on, the oscillator's audio signal current flows through the electric coil to make a magnetic field. The electric coil and the magnet cause the vibrating diaphragm to move and make sounds at regular intervals. The general electromagnetic warning frequency is 2-4 kHz.

Fig 4. A magnetic buzzer structure

Mechanical Buzzers

Mechanical buzzers use a motor-driven mechanism to produce sound. They are often large and consume a lot of power. They are commonly used in older electronic devices and appliances, such as doorbells and alarm clocks.

Transducer Buzzers

Transducer buzzers use a combination of piezo and magnetic elements to produce sound. They are often used in harsh environments, such as in outdoor applications or industrial settings.

SMD Buzzers

Surface Mount Device (SMD) buzzers are small, compact buzzers that are designed to be mounted directly on a printed circuit board. They are often used in small electronic devices, such as smartphones, tablets, and other portable devices.

These are just a few examples of the many types of buzzers available. The choice of buzzer type depends on the specific application and the requirements of the design, such as the size, power consumption, and sound output needed.

Buzzer Types Division Based on the Control Method

Active Buzzer (with drive line)

When the internal oscillator is energized, the buzzer sounds. The ideal signal is a direct current, usually marked as VDC, VDD, etc., which can convert a constant direct current into a pulse signal of a certain frequency.

Passive Bus (external drive)

There is no internal oscillator. It cannot be chirped by a DC signal. It should be driven by a 2K~5K square wave because the magnetic circuit is fixed.

How to Distinguish an Active Buzzer from an Inactive one

The height of the active buzzer is slightly different from the passive one. The active buzzer is usually 9 mm, and the passive buzzer is 8 mm high. When placing two buzzers with the pins facing up, the passive buzzer's mod plate is green, and the active buzzer is without a vinyl-sealed circuit board.

Rxl multimeter Resistance Test

Connect the multimeterblack lead to the '+' pin and the red one to the other pin. If it ticks and the resistance is 8Ω (or 16Ω), then the buzzer is passive; Connect the black pen to the "+" pin of the viewer and connect the red one to the beginning and end of the other pin. If a continuous sound is emitted and its resistance is more than a few hundred ohms, then the buzzer is active.

Fig 5. Illustrating Black glue and circuit board on buzzer structure

The active buzzer produces sound continuously when connected to a rated power supply (note on the label). Passive buzzers are similar to electromagnetic speakers and must be connected to the output of the audio circuit for sound.

Tips on Choosing the Right Buzzer

The buzzer specifications are different. The appropriate buzzer can be selected by several main parameters (voltage, current, mode of movement, size, connection mode / fixed) and required sound (sound pressure and frequency).

1.Working voltage

The working voltage of the electromagnetic buzzer can be 1.5–24 V, and the working voltage range of the piezoelectric buzzer can be 3–220 V. However, under normal conditions, it is recommended that the working voltage range of the piezoelectric buzzer be more than 9V to produce a louder sound.

2.Current consumption

According to different voltages, the electromagnetic buzzer can consume a current of tens to hundreds of milliamperes, while the piezoelectric buzzer needs a few milliamperes for normal operation.

3.How to control

Choose active or inactive buzzers according to specific needs.

4.Size

Buzzer size affects volume and frequency. The size of the electromagnetic buzzer is generally 7 to 25 mm, and the piezoelectric buzzer is 12-50 mm.

5.Sound pressure

A distance of 10 cm is used as a standard test for buzzers. If the distance is doubled, the attenuation will be about 6 dB. Conversely, if the distance is shortened, it will exceed 6 dB. The electromagnetic buzzer can reach a level of 85dB / 10 cm, while the piezoelectric buzzer can make a louder sound. Most common alarms are made from piezoelectric sensors.

Buzzer Control Circuit

Because the operation current of the buzzer is generally high, the input/output port of the single-chip microcomputer cannot be directly driven (but the AVR can drive a small electric buzzer), so the amplifier circuit must be used for driving, and generally a triode is used to amplify the current. The market drive circuit generally includes the following parts:

Triode, buzzer, freewheeling diode, and power filter capacitor.

1.Buzzer

When DC voltage (for an active buzzer) or square wave (passive buzzer) is applied to both ends of the sound element, its main parameters are shape dimensions, sound direction, working voltage, working frequency, working current, motion mode, etc., which can be chosen according to the need.

2.Freewheeling diode

The buzzer is an inductive element and its current cannot be changed temporarily. Therefore, a freewheeling diode should be used for constant current. Otherwise, an alternating voltage of ten volts is applied to both ends of the warning buzzer, which may damage the triode and interfere with other parts of the circuit.

3.Filter capacitor

The function of the filter capacitor is to filter the influence of the buzzer current on other components and improve the AC impedance of the power supply. If possible, it is better to parallel a 220uF electrolytic capacitor.

4.Triode

A high base level causes the triode to saturate and produce a buzzer sound. While the low base level causes the triode to close and stop the buzzer sound.

Precautions When Using Buzzer

It is not allowed to use the buzzer in an environment other than the specified temperature (when the buzzer works outside the specified temperature, the performance of the piezoelectric sheet and shell will change and the sound will be low).

Welding must be done according to the specified method. Common methods of buzzer welding are manual welding, wave soldering, and re-soldering.

Prevent foreign material from entering the buzzer sound hole (Foreign material entering the buzzer sound hole may affect the vibration of the diaphragm and indicate small or abnormal sounds).

For the buzzer that is not waterproof, it is necessary to prevent the buzzer from being placed where it may come into contact with water (for this buzzer, buzzing, short-circuiting, and blockage of parts vibration will occur after water enters).

Do not use outside the specified working voltage (when the voltage is too high, it will cause an arcing phenomenon, which will lead to the cracking of the ceramic chips and the weakening of the electric field).

What are the Advantages and Disadvantages of Using the Buzzer?

Advantages of Using a Buzzer

1.Audible alert

A buzzer provides an audible alert that can be easily heard, making it an effective way to signal an event or condition.

2.Low cost

Buzzers are relatively inexpensive and can be easily integrated into electronic circuits.

3.Low power consumption

Piezo buzzers consume very little power, making them ideal for low-power applications.

4.Compact size

Some types of buzzers, such as SMD buzzers, are very small and can be easily integrated into small electronic devices.

5.Simple to use

Buzzers are easy to use and require minimal programming or configuration.

Disadvantages of Using a Buzzer

1.Limited functionality

Buzzers can only produce a single type of sound and are not capable of producing complex tones or melodies.

2.Harsh sound

The sound produced by a buzzer can be harsh and unpleasant to listen to, especially if the sound level is high.

3.Limited range

The range of a buzzer is limited, and the sound may not be audible at long distances or in noisy environments.

4.Limited control

The control over the sound produced by a buzzer is limited, and it may not be possible to adjust the volume or tone of the sound.

Overall, buzzers are a simple and cost-effective way to provide an audible alert on electronic devices. However, they have some limitations in terms of functionality, sound quality, and control.

Conclusion

In conclusion, a buzzer is an electronic device that produces an audible sound to alert or signal an event or condition. There are several types of buzzers available, each with its unique features and applications, such as piezo buzzers, magnetic buzzers, mechanical buzzers, transducer buzzers, and SMD buzzers. When choosing the right buzzer for a particular application, factors such as sound output, power consumption, size, operating voltage, operating temperature range, and environmental factors must be considered. While buzzers have advantages such as low cost, low power consumption, and simple use, they also have limitations in terms of functionality, sound quality, and control.

To Recap

Q: What is the difference between a piezo buzzer and a magnetic buzzer?

A: The main difference between a piezo buzzer and a magnetic buzzer is the way they produce sound. Piezo buzzers use a piezoelectric crystal to produce sound when an electrical signal is applied, while magnetic buzzers use a coil and a diaphragm to produce sound.

Q: What is the operating voltage of a buzzer?

A: The operating voltage of a buzzer can vary depending on the type and model of the buzzer. It is important to choose a buzzer that has an operating voltage that matches the voltage output of the drive circuit to ensure proper operation.

Q: What is the sound output of a buzzer?

A: The sound output of a buzzer can vary depending on the type and model of the buzzer. Piezo buzzers are typically quieter than magnetic buzzers, but they can still produce sound levels of up to 100 dB or more.

Q: What is the lifespan of a buzzer?

A: The lifespan of a buzzer can vary depending on several factors, such as the type and model of the buzzer, the operating conditions, and the frequency of use. Generally, buzzers can last for several years with proper use and maintenance.

Q: Can I adjust the sound level of a buzzer?

A: Some types of buzzers, such as piezo buzzers, have built-in sound level control circuits that allow the sound level to be adjusted. However, other types of buzzers may not have this feature, and the sound level cannot be adjusted.

Q: Can I use a buzzer in a wet or humid environment?

A: Some buzzers are designed to be water-resistant or waterproof and can be used in wet or humid environments. However, it is important to choose a buzzer that is specifically designed for these conditions to ensure proper operation and reliability.

Q: Can I use a buzzer in a high-temperature environment?

A: Some buzzers are designed to operate in high-temperature environments, but it is important to choose a buzzer that has an operating temperature range that is suitable for the application. Operating a buzzer outside of its specified temperature range can result in reduced performance or damage to the buzzer.