A piezoelectric speaker is a type of speaker that uses the piezoelectric effect to produce sound. It is a type of loudspeaker that generates sound by using the piezoelectric effect. The piezoelectric effect is a phenomenon where certain materials, such as quartz, generate an electric charge when they are subjected to mechanical stress. This effect can be used to convert electrical energy into mechanical energy, and vice versa.
A voltage is applied to a piezoelectric material to generate mechanical motion, which is then converted into audible sound using diaphragms and resonators. The prefix piezo- means ‘press’ or ‘squeeze’ in Greek.
In a piezoelectric speaker, an electrical signal is applied to a piezoelectric crystal, causing it to vibrate and produce sound waves. The crystal is typically mounted on a thin metal plate, which acts as a diaphragm to amplify the sound waves. Piezoelectric speakers are known for their high efficiency, durability, and ability to produce clear, high-frequency sound.
In comparison to other speaker designs, piezoelectric speakers are relatively simple to drive; for example, they can be connected directly to TTL outputs, though more complex drivers can produce more intense sound. In ultrasound applications, they typically operate well in the 1-5 kHz range and up to 100 kHz.
Due to their electrical properties, piezoelectric speakers have several advantages over conventional loudspeakers: they are resistant to overloads that would normally destroy most high-frequency drivers, and they can be used without a crossover. There are also drawbacks: some amplifiers, such as most piezoelectrics, can oscillate when driving capacitive loads, resulting in distortion or damage to the amplifier. Furthermore, in most cases, their frequency response is inferior to that of other technologies, particularly in the bass and midrange. As a result, they are most commonly used in applications where volume and high pitch are more important than sound quality.
Usage
Piezoelectric speakers are commonly used to generate sound in digital quartz watches and other electronic devices, and they are also used as tweeters in less-expensive speaker systems such as computer speakers and portable radios. They are also used in sonar systems to generate ultrasound.
Piezoelectric speakers are commonly used in applications where small size and low power consumption are important, such as in alarm clocks, toys, and electronic devices. They are also used in some musical instruments, such as acoustic guitars, where they are used to amplify the sound of the strings. However, they are not typically used in high-end audio applications, where more complex and expensive speaker designs are used to achieve the best sound quality.
