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A piezoelectric speaker (also known as a piezo bender due to its mode of operation, and sometimes colloquially called a "piezo", buzzer, crystal loudspeaker or beep speaker) is a loudspeaker that uses the piezoelectric effect for generating sound. The initial mechanical motion is created by applying a voltage to a piezoelectric material, and ...
A buzzer or beeper is an audio signaling device, [1] which may be mechanical, electromechanical, or piezoelectric (piezo for short). Typical uses of buzzers and beepers include alarm devices , timers , train and confirmation of user input such as a mouse click or keystroke.
Metal disks with piezo material, used in buzzers or as contact microphones. Piezoelectric technology can measure various physical quantities, most commonly pressure and acceleration. For pressure sensors, a thin membrane and a massive base is used, ensuring that an applied pressure specifically loads the elements in one direction.
More recent computers use a tiny moving-iron or piezo speaker instead. [2] The speaker allows software and firmware to provide auditory feedback to a user, such as to report a hardware fault. A PC speaker generates waveforms using the programmable interval timer , an Intel 8253 or 8254 chip.
Begin using briefed radio procedures to counter communications jamming. Cheapshot (USAF) Active missile supported to high pulse repetition frequency (HPRF, better against oncoming targets), but not medium pulse repetition frequency (MPRF, better against targets flying away). (Naval) Active missile not supported to active range. Check turn (deg)
A Bridge Navigational Watch Alarm System, abbreviated BNWAS, is an automatic system which sounds an alarm if the watch officer on the bridge of a ship falls asleep, becomes otherwise incapacitated, or is absent for too long a time.
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These active detectors transmit ultrasonic sound waves that are inaudible to humans using frequencies between 15 kHz and 75 kHz. The Doppler shift principle is the underlying method of operation which detects a change in frequency due to object motion. This detection occurs when the object must cause a change in the ultrasonic frequency to the ...