Buzzer
A buzzer or beeper is an audio signalling device, which may be mechanical, electromechanical, or piezoelectric. Typical uses of buzzers and beepers include alarm devices, timers and confirmation of user input such as a mouse click or keystroke.
History
Electromechanical
The first electric buzzer was invented in 1831 by Joseph Henry. They were mainly used in early doorbells until they were phased out in the early 1930s in favor of musical chimes, which had a softer tone.
Piezoelectric
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.
Type of buzzers
Electromechanical
Buzzer (whirligig)
A buzzer (buzz, bullroarer, button-on-a-string), is an ancient mechanical device used for ceremonial purposes and as a toy. It is constructed by centring an object at the midpoint of a cord or thong and winding the cord while holding the ends stationary. The object is whirled by alternately pulling and releasing the tension on the cord. The whirling object makes a buzzing or humming sound, giving the device its common name.
A buzzer is often constructed by running string through two of the holes on a large button and is a common and easily made toy.
American Indians used the buzzer as a toy and, also ceremonially, as to call up the wind. Early Indian buzzers were constructed of wood, bone, or stone, and date from at least the Fourche Maline Culture, c. 500 B.C.
See also
References
Bibliography
Buzzer (disambiguation)
A buzzer is a signalling device.
Buzzer or The Buzzer may also refer to:
Digi
Digi may refer to:
See also
Digi 24
Digi 24 is a 24-hour Romanian news television, which was launched on 1 March 2012 by Digi TV.
History
10 TV, a generalist television channel, was launched on 10 December 2010, by RCS&RDS. 10 TV hosted Nașul show, which Radu Moraru had anchored for ten years on B1 TV. 10 TV was re-launched with a new name. On 1 March 2012, 10 TV was rebranded to Digi 24. by branding agency Kemistry
References
External links
Digi Telecommunications
Digi Telecommunications Sdn. Bhd., DBA digi, is a mobile service provider in Malaysia. It is owned in majority by Telenor ASA of Norway with 49%. On 24 May 1995 Digi became the first telco in Malaysia to launch and operate a fully digital cellular network.
They were also the first to offer GPRS (2.5G) and later EDGE (2.75G) in Malaysia on 14 May 2004. DiGi primarily uses the 1800 MHz band for GSM with the network code of 502-16.
Digi is listed on the Bursa Malaysia under the Infrastructure category act.
It uses the native dialling prefix identifier of "010", "016", "0143", "0146" and "0149", although with the implementation of Mobile number portability mandated by the Malaysian government this does not apply to subscribers who switched from their old mobile service provider over to Digi. At the moment, switching to DiGi is free.
Coverage, Products, and Services
As of December 2015, DiGi has 2G coverage of 95% on populated areas, 3G at 87%, 4G LTE at 65%. LTE-Advanced (LTE-A) population coverage is currently at 28.8% nationwide, likely measured at the lowest signal quality at -110dBm.
Dae
Dae can refer to:
