Abuzzer orbeeper is anaudio signaling device,[1] which may bemechanical,electromechanical, orpiezoelectric (piezo for short). Typical uses of buzzers and beepers includealarm devices,timers,train and confirmation of user input such as a mouse click or keystroke.
The electric buzzer was invented in 1831 byJoseph Henry. They were mainly used in earlydoorbells until they were phased out in the early 1930s in favor of musical chimes, which had a softer tone.[2]
Piezoelectric buzzers, or piezo buzzers, as they are sometimes called, were invented by Japanese manufacturers and fitted into a wide array of products during the 1970s to 1980s. This advancement mainly came about because of cooperative efforts by Japanese manufacturing companies. In 1951, they established the Barium Titanate Application Research Committee, which allowed the companies to be "competitively cooperative" and bring about several piezoelectric innovations and inventions.[3]
Early devices were based on an electromechanical system identical to anelectric bell without the metal gong. Similarly, arelay may be connected to interrupt its own actuatingcurrent, causing thecontacts to buzz (the contacts buzz atline frequency if powered byalternating current) Often these units were anchored to a wall or ceiling to use it as a sounding board. The word "buzzer" comes from the rasping noise that electromechanical buzzers made.
Ajoy buzzer is an example of a purely mechanical buzzer and they require drivers. Other examples of them are doorbells.
Apiezoelectric element may be driven by anoscillating electronic circuit or otheraudio signal source, driven with apiezoelectric audio amplifier. Sounds commonly used to indicate that a button has been pressed are a click, a ring or a beep.
A piezoelectric buzzer/beeper also depends on acoustic cavity resonance orHelmholtz resonance to produce an audible beep.[4]
While technological advancements have caused buzzers to be impractical and undesirable[citation needed], there are still instances in which buzzers and similar circuits may be used. Present day applications include:
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