Jiangsu HUAWHA Electronics Co., Ltd.

In modern electronic devices, buzzers are important acoustic prompt components, and their selection directly affects the user experience and performance of the product. This article will deeply analyze the technical differences between piezoelectric buzzers and electromagnetic buzzers to help you make wise choices.

1. Working principle: two completely different sound logics

The core function of the buzzer is to "convert electrical energy into sound energy", but the way piezoelectric buzzers and electromagnetic buzzers achieve this conversion is completely different, which is also the most essential difference between the two.

The operation of piezoelectric buzzers depends on the "piezoelectric effect". The so-called piezoelectric effect refers to the fact that some special materials (such as piezoelectric ceramics) will generate electric charges when squeezed by external forces, and conversely, when these materials are passed through alternating current, they will produce periodic expansion and contraction deformation. Piezoelectric buzzers use this "inverse piezoelectric effect": its core component is a piezoelectric ceramic sheet. When an alternating voltage is applied to both ends of the ceramic sheet, the ceramic sheet will expand and contract rapidly with the change of current (up to thousands of times per second). This high-frequency vibration is transmitted through the air, forming the sound we hear. Simply put, it is like a "breathing crystal" that "moves" and makes sounds when powered on.

The electromagnetic buzzer works based on the principle of electromagnetic induction. Its core structure is a small electromagnet: composed of a coil, a permanent magnet and a metal vibrating sheet. When the coil is connected to an alternating current, an alternating magnetic field is generated. This magnetic field interacts with the magnetic field of the permanent magnet (attracts or repels), driving the metal vibrating sheet to vibrate rapidly, thereby pushing the air to make sounds. Figuratively speaking, it is more like a "micro pile driver" that "pulls" the metal sheet back and forth through magnetic force to produce sound.

In principle, the sound of the piezoelectric buzzer depends on the characteristics of the material itself, and the structure is more "passive"; while the electromagnetic buzzer actively drives the movement of the components through the magnetic field force, and the structure is more "active". This difference directly affects the performance and applicable scenarios of the two.

2. Structural composition: component differences determine performance boundaries

Structure is the basis of performance. The difference in the internal composition of the two buzzers further amplifies their functional differences.

The structure of a piezoelectric buzzer is relatively simple, and its core components include piezoelectric ceramic sheets, metal vibration plates, and shells. Piezoelectric ceramic sheets are usually pasted on metal vibration plates. After the two are combined, the expansion and contraction of the ceramic sheets will drive the vibration plates to vibrate synchronously, enhancing the sound effect; the shell protects the internal components and gathers the sound, and some shells are designed into specific shapes to optimize the propagation direction of the sound. Since no complex electromagnetic components are required, the overall structure of the piezoelectric buzzer can be made very light and thin, and can even be integrated into a circuit board with a thickness of less than 1 mm.

The structure of the electromagnetic buzzer is more complicated, mainly consisting of a coil, a permanent magnet, a metal vibration sheet, a bracket, and a shell. The coil is wound on the bracket, maintaining a certain gap with the permanent magnet; the metal vibration sheet is fixed on the bracket, with one end close to the permanent magnet. When the coil is energized, the magnetic field generated will interact with the magnetic field of the permanent magnet, causing the metal vibration sheet to be "sucked" or "pushed away", thereby generating vibration. This structure needs to accommodate the coil and the permanent magnet, so the overall size is usually slightly larger than that of a piezoelectric buzzer with the same performance, and the thickness is more difficult to compress.

The difference in structure also brings about a difference in durability: piezoelectric buzzers have no moving parts that are easy to wear (the expansion and contraction of ceramic sheets belong to microscopic deformation), and the theoretical life is longer; the metal vibrating sheet in the electromagnetic buzzer is a high-frequency moving part, and long-term use may lead to performance degradation due to fatigue, especially in harsh environments such as high temperature and high humidity.

3. Performance comparison: all-round differences from power consumption to volume

Performance is the core basis for selecting a buzzer. Piezoelectric buzzers and electromagnetic buzzers have their own advantages and disadvantages in key indicators such as power consumption, volume, and frequency, which need to be judged in combination with specific needs.

Power consumption: piezoelectric buzzers are more "power-saving"

The power consumption of piezoelectric buzzers is generally low, usually between 0.1-10mA. This is because its sound generation depends on the natural vibration of piezoelectric materials, and it does not need to continuously consume energy to maintain the magnetic field. For products that rely on battery power, such as remote controls, smart bracelets, and portable medical devices, low power consumption means longer battery life, which is a significant advantage of piezoelectric buzzers.

The power consumption of electromagnetic buzzers is relatively high, generally between 10-50mA. Since it needs to continuously power the coil to generate a magnetic field, the energy consumption is greater. Therefore, in battery-powered devices, electromagnetic buzzers are usually only used in scenarios that require short-term sounding (such as car reversing prompts), and are not suitable for devices that are on standby for a long time and frequently sound.

Volume: Electromagnetic buzzers are "louder"

Volume is one of the core performance of the buzzer, usually measured in decibels (dB). Under the same power supply conditions, the volume of electromagnetic buzzers is generally higher than that of piezoelectric buzzers, especially in the low frequency band (200-1000Hz). This is because the vibration amplitude of the metal vibrating plate is larger, which can push more air to generate sound waves, and is suitable for scenarios that require "strong penetration", such as alarms in industrial workshops and fire warnings in large shopping malls.

The volume of piezoelectric buzzers is relatively low, and they are better at making sounds in the high frequency band (1000-5000Hz). The characteristics of high-frequency sound are strong directionality and fast attenuation, which are suitable for close-range prompts, such as operation feedback of home appliances, message reminders of smart watches, etc., and will not cause interference due to excessive volume.

Frequency range: each has its own "sound range"

The frequency of the buzzer determines the "tone" of the sound. The higher the frequency, the sharper the tone; the lower the frequency, the thicker the tone. The frequency range of the piezoelectric buzzer is narrow, mainly concentrated in 1000-5000Hz, and the high-frequency response is better, which can produce crisp and sharp sounds. Although this kind of sound is not as penetrating as the low frequency in a noisy environment, it has high recognition and is suitable for scenes that require "precise prompts".

The frequency range of the electromagnetic buzzer is wider, covering 200-3000Hz, especially stable in the medium and low frequency bands, and can produce a thicker and lower sound. This kind of sound has a long transmission distance and is suitable for scenes that require "wide-range warnings", such as warehouse security alarms, outdoor equipment fault prompts, etc.

Size and weight: piezoelectric buzzers are more "compact"

Affected by the structure, piezoelectric buzzers can be made thinner and lighter. The thickness of common piezoelectric buzzers can be as low as 0.5mm, and the minimum diameter is only 3mm, which is very suitable for installation in devices with strict space requirements such as smartphones and smart glasses.

Because electromagnetic buzzers contain coils and permanent magnets, the size is difficult to compress. The common thickness is 2-10mm and the diameter is 5-20mm. It is more suitable for installation in devices with relatively ample space such as car center consoles and industrial control cabinets.

Environmental adaptability: piezoelectric buzzers are more "durable"

The core component of piezoelectric buzzers is piezoelectric ceramics. This material is insensitive to changes in temperature and humidity. It can work stably in an environment of -40℃ to 85℃, and has good vibration and impact resistance. It is suitable for complex environments such as outdoor equipment and vehicle-mounted electronics.

The coils and metal vibrating sheets in electromagnetic buzzers are more sensitive to the environment: high temperature may cause aging of the coil insulation layer, humidity may cause rusting of metal parts, and severe vibration may cause the vibrating sheet to loosen. Therefore, it is more suitable for use in indoor, normal temperature, and low humidity environments, such as household refrigerators and washing machines.

4. Applicable scenarios: Match the most suitable type according to needs

After understanding the performance differences between the two, we can determine which buzzer to choose according to the specific usage scenarios.

Typical application scenarios of piezoelectric buzzers

Portable electronic devices: such as remote controls, smart bracelets, electronic thermometers, etc. These devices rely on batteries for power supply and have high requirements for power consumption and size. The low power consumption and small size characteristics of piezoelectric buzzers are just right.

Precision instruments: such as medical monitors, laboratory equipment, etc. These devices require clear but not harsh prompt sounds. The high-frequency sound of piezoelectric buzzers can convey information without interfering with operations.

Outdoor equipment: such as solar warning lights, field alarms, etc. These devices need to work under extreme temperatures and humidity. The environmental adaptability of piezoelectric buzzers has obvious advantages.

Typical application scenarios of electromagnetic buzzers

Industrial alarm systems: such as factory fault alarms, production line safety reminders, etc. These scenarios require loud and long-distance sound transmission. The low-frequency and high-volume characteristics of electromagnetic buzzers are more suitable.

Automotive electronics: such as reversing radar, seat belt unfastened reminder, door open alarm, etc., the interior space of the car is relatively ample, and there is a stable power supply, which can meet the power consumption requirements of the electromagnetic buzzer, and its deep sound can also be clearly heard in the noisy environment of the car.

Large household appliances: such as microwave ovens, dishwashers, air conditioners, etc., these devices are installed indoors, the environment is stable, and medium-volume prompt sounds are required. The performance and cost of electromagnetic buzzers are more advantageous.

5. Purchase suggestions: Priority sorting of key indicators

In actual purchase, facing a variety of product parameters, you don’t have to be comprehensive, just sort according to core needs.

If power consumption and size are given priority: for example, when choosing a buzzer for a smart watch, piezoelectric buzzers are the first choice, focusing on their operating voltage (usually 3V or 5V) and static power consumption.

If you prioritize volume and propagation distance: for example, if you choose an alarm for a warehouse, an electromagnetic buzzer is more suitable, and focus on its decibel number at a distance of 1 meter (recommended ≥85dB) and frequency range (recommended 200-1000Hz).

If you prioritize environmental adaptability: for example, if you choose a buzzer for outdoor equipment, a piezoelectric buzzer is more reliable, and focus on its operating temperature range and protection level (such as IP65 dust and water resistance).

If the budget is limited: Under the same performance, the cost of electromagnetic buzzers is usually lower, which is suitable for civilian equipment purchased in batches.

Summary: Choose the right buzzer to make sound transmission more accurate

Piezoelectric buzzers and electromagnetic buzzers are not "who is better", but "who is more suitable".

Piezoelectric buzzers win with low power consumption, small size, and strong environmental adaptability, and are suitable for portable, precision, and outdoor scenes; electromagnetic buzzers are known for high volume, wide frequency, and low cost, and are suitable for industrial-grade, high-volume, and indoor fixed scenes. When choosing, you only need to clarify the power supply method, space limitations, volume requirements and usage environment of your own equipment to quickly lock in the target type.

Of course, a high-quality buzzer must not only match the performance, but also have stable quality control and consistency. Among many buzzer manufacturers, HUAWHA can provide adaptive solutions according to the needs of different scenarios by virtue of its in-depth research and development of two types of products. It has been rigorously tested from material selection to performance debugging to ensure that each product can function stably, making it a trustworthy choice.