Piezo Buzzers Provide The Best Audio Signaling Applications

In common language, buzzer is an audio signaling device and not a loudspeaker. The multiple types of buzzers are: electrical, mechanical, electro-mechanical, magnetic, electro-magnetic, electro-acoustic and piezoelectric. A piezo buzzer can produce the sound for household goods, medical devices, audible alarms, game shows, sporting events, electronic metronomes, indicators, etc. These have very clear sounds and optimum sound pressure. These buzzers can be used to alert a user for the event corresponding to a switching action, counter signal or sensor output. Most of the buzzers sound in the range 2-4 KHz.

They are available in different mounting configurations like, panel mounting, thru hole, surface mounting, flange, snap-in, vertical mount, PCB mount or wire leads. The tone nature of these piezo buzzers comes in different styles like continuous, pulsing, 6 or 7 different set of tones, etc. They are available in different sizes too with RoHS compliance. Some of the buzzers can be customized in SPL according to the requirement.

The various manufacturers have come up with idea of customized products having different size, mounting choice, tones and other things with respect to the order of the user. The manufacturers employ engineers to deliver the perfect piezo buzzers satisfying the given design criteria.

The piezoelement is essentially the heart of the buzzer. It is present in the enclosure so that sound can be created inside. A piezoelement of ceramic when exposed to the alternating electrical field it changes dimensions cyclically, at the frequency of the field. The frequency at which the element vibrates the most readily in response to electrical input and converts the electrical energy into mechanical energy is called the resonance frequency which is determined by the materials shape, composition and size. There are manufacturers who produce these products in different shapes and size according to the user requirements.

The different parameters that can get customizable buzzers are:

• Sound Pressure Level (SPL): It is the local pressure deviation from the ambient atmospheric pressure caused by a sound wave. It is a major property which depends on the input voltage.
• Resonant Frequency: The frequency, at which the response amplitude is relatively maximum is measured in terms of hertz and gets varied on the vibrating frequency. Driving a system at its resonant frequency create largest amplitudes with smallest inputs. The buzzers are the loudest when driven in their resonant frequencies.
• Frequency Response: It depends on the requirement, the manufacturer are available with parts having different frequency responses.
• Sound Effects: Different kind of buzzers serves in different purposes like in medical devices, computers, toys, household appliances, etc. They could be high/low, slow/fast for feedback or warning signal, continuous, multiple tones, sirens, chiming etc.

In terms of comparison with the Magnetic buzzers, the piezo buzzers are a lot better than them, as the latter one have wide operating voltages, lower current consumption, high rated frequency, larger footprint and higher sound pressure level. These are versatile products that come with different mechanisms having specific features and output ranges.

Irving Blair is an acoustic equipment expert. He uses various acoustic products and reviews its performance. Recently he reviewed Piezo buzzer and recommend this piezoelement for various industrial usages.