A piezo buzzer is a type of buzzer that uses the piezoelectric effect to convert electrical energy into sound energy. Due to its efficiency, compact size, and low power consumption, it is widely used in electronic devices for alarms, notifications, and feedback sounds. This article will delve into the working principle, classification, and typical application scenarios of piezo buzzers.
Working Principle of Piezo Buzzers
The core component of a piezo buzzer is a piezoelectric ceramic disk. When an electrical signal is applied to the piezoelectric material, it undergoes mechanical deformation, causing it to vibrate and produce sound waves. The process is as follows:
- Electrical Signal Input: A voltage signal is applied to the piezoelectric ceramic disk.
- Piezoelectric Effect: The piezoelectric material deforms under the applied voltage, generating tiny vibrations.
- Sound Emission: Through these vibrations, the piezoelectric disk resonates with the surrounding air, producing sound.
Piezo buzzers typically use a square wave drive, where the volume and frequency of the sound are related to the frequency of the applied voltage. As a result, variations in the electrical signal frequency within the audio range will cause the buzzer to produce sounds at different frequencies.
Classification of Piezo Buzzers
Piezo buzzers are typically classified into the following categories based on design and application requirements:
Active Piezo Buzzers
Active buzzers have an integrated driver circuit, requiring only a simple DC signal to operate and produce a fixed sound. These buzzers are easy to use but their frequency is fixed and not adjustable.
Passive Piezo Buzzers
Passive buzzers lack an integrated driver circuit and require an external audio signal to drive them. The frequency is adjustable, making them suitable for applications that require multiple tones or frequency variations. However, they require more complex drive circuits.
Surface Mount Piezo Buzzers
These buzzers are designed to be compact and are suitable for surface mounting. They are widely used in small devices, wearable devices, and other products where space is at a premium.
This classification helps in selecting the right type of piezo buzzer based on the specific needs of the application, such as tone variety, integration complexity, and space constraints.
Common Models of Piezo Buzzers
Piezo buzzers come in a variety of models, each designed for specific circuits and application scenarios. Below are some common piezo buzzer models and their features:
1. TDK PS Series
- Example Model: PS1240P02BT
- Features: The PS series buzzers are compact and low-power, making them ideal for portable and small electronic devices. Most of the PS series buzzers offer a wide frequency response range.
- Applications: Consumer electronics, home appliances for sound alerts.
2. Murata PK Series
- Example Model: PKM17EPP-4001-B0
- Features: Murata's PK series piezo buzzers are small, loud, and typically capable of producing up to 85 decibels of sound. This series is compatible with low-voltage operation, making them suitable for power-sensitive applications.
- Applications: Smart home devices, medical devices, security equipment.
3. CUI Devices CEP Series
- Example Model: CEP-1120C
- Features: The CEP series from CUI Devices includes both active and passive models, offering versatility for various applications. These buzzers are known for moderate sound output and stable frequencies, with some models supporting adjustable frequencies.
- Applications: Consumer electronics, industrial automation systems.
4. Kingstate KPM Series
- Example Model: KPM-1210
- Features: The KPM series buzzers are known for their high-frequency range and loud sound, making them suitable for applications that require higher sound levels. Many models in this series support various installation methods, providing flexibility for different device structures.
- Applications: Medical equipment, automotive electronics, security systems.
5. Mallory Sonalert S Series
- Example Model: SC628N
- Features: The S series from Sonalert is typically known for its high sound level output and durability, able to withstand harsh environments. Many models in this series are also rated for specific protection levels, making them suitable for outdoor or industrial use.
- Applications: Industrial alarms, security alert systems, outdoor equipment.NOTHING
6. SOB Series Piezo Buzzers
- Example Model: SOB-1205T
- Features: The SOB series buzzers are widely used for their high sound output and quick response time. They are compatible with a range of operating voltages and are suitable for alarm systems, consumer electronics, and more.
- Applications: Fire alarms, gas detectors, home appliances.
7. Sunrise Series Piezo Buzzers
- Example Model: ST-1230
- Features: The Sunrise series piezo buzzers are compact and lightweight, with some models designed for surface-mount technology (SMT), making them ideal for mass production. Many models can produce up to 90 decibels of sound.
- Applications: Automotive reverse sensors, consumer electronics, instrumentation.
Key Considerations When Choosing Piezo Buzzers
When selecting a piezo buzzer model, it's important to consider factors such as:
- Operating Voltage: Ensure that the buzzer’s rated operating voltage matches your circuit system.
- Volume and Frequency: Consider whether the volume and frequency range are appropriate for the intended alert or notification function.
- Size and Mounting Style: Determine if you need surface-mount or through-hole mount based on your product’s design.
- Environmental Conditions: If the buzzer will be used in outdoor or industrial environments, select a model that can withstand the required temperature range and environmental factors.
These models represent only a portion of the piezo buzzers available in the market, each designed to meet specific needs in various application scenarios.
