DIGITAL DEVICES
A digital device is an electronic device which uses
discrete, numerable data and processes for all its operations. The alternative
type of device is analog,
which uses continuous data and processes for any operations. Any device which uses a
computer of any sort in its operations is at least partially digital.
Digital devices have been in
existence for well over 100 years, with the first digital device in widespread
use being the telegraph. The telegraph was used to translate text into a series
of dots and dashes, which were transferable along a line from one telegraph to
another to allow for long-distance communications.
The telephone later replaced the
telegraph as a widely used digital device, though earlier telephone systems
also had an analog component that was used to transfer the voice portion of the
call. The digital portion of earlier telephones was used to convey telephone
number data, routing two or more phones to establish connections between them
without the need for manual help from operators. Recent phone systems are
entirely digital, however, with the audio converted into data for transfer
along the phone line, where it is converted back into audio at the other end.
Modems are another recent example
of a digital device, serving the same purposes as the old telegraph lines in
converting analog information such as text, audio and video into digital
signals for transmission along a networking cable.
EXAMPLES
OF DIGITAL DEVICES
v
Computer
A computer is a device
that can be instructed to carry out an arbitrary set of arithmetic or logical operations automatically. The ability of computers to follow
a sequence of operations, called a program, make computers very flexible and useful. Such
computers are used as control systems for a very wide variety of industrial and consumer devices. This includes simple special purpose devices
like microwave ovens and remote controls, factory devices such as industrial robots and computer assisted
design, but
also in general purpose devices like personal computers and mobile devices such as smartphones. The Internet is run on computers and it connects millions of other
computers.
v Digital camera
A digital camera or digicam is a camera that produces digital images that can be
stored in a computer, displayed on a screen and printed. Most cameras sold
today are digital, and digital
cameras are incorporated into many devices ranging from PDAs and mobile phones (called camera phones) to vehicles.
Digital and movie cameras share an optical system, typically using
a lens with a variable diaphragm to focus light onto an image pickup
device. The diaphragm and shutter admit the correct amount of light to the imagery, just as with film but the image pickup device is electronic rather than
chemical. However, unlike film cameras, digital cameras can display images on a
screen immediately after being recorded, and store and delete images from memory. Many digital cameras can also record moving videos with sound. Some digital cameras can crop and stitch pictures and perform other elementary image editing.
v MP3 player
An MP3 player or Digital Audio Player is
an electronic device that can play digital audio files. It is a type of Portable Media
Player. The term 'MP3
player' is a misnomer, as most players play more than the MP3 file format.
v
Mobile phone
A mobile phone is a
portable telephone that
can make and receive calls over
a radio frequency link while the user is moving within a telephone
service area. The radio frequency link establishes a connection to the
switching systems of a mobile phone
operator, which provides access to
the public
switched telephone network (PST.
Most modern mobile telephone services use a cellular network architecture, and therefore mobile telephones are
often also called cellular telephones or cell phones. In addition to telephony,
2000 s-era mobile phones support a variety of other services,
such as text messaging, MMS, email, Internet access,
short-range wireless communications (infrared, Bluetooth),
business applications, gaming, and digital photography. Mobile phones which offer these and more general
computing capabilities are referred to as smartphones.
The first handheld mobile phone was demonstrated by John F. Mitchell and Martin Cooper of Motorola in
1973, using a handset weighing c. 4.4 lbs (2 kg). In 1983, the DynaTAC 8000 x was the first commercially available handheld mobile
phone. From 1983 to 2014, worldwide mobile phone subscriptions grew to over
seven billion, penetrating 100% of the global population and reaching even the bottom of the
economic pyramid. In first quarter of
2016, the top smartphone manufacturers were Samsung, Apple and Huawei .
v DVD Player
DVD (an abbreviation of "digital versatile disc" or
"digital video disc"
is a digital optical disc storage format invented and
developed by Philips, Sony, Toshiba, and Panasonic in 1995. The medium can store any kind of
digital data and is widely used for software and other computer files as well
as video programs watched using DVD players. DVDs offer higher storage capacity than compact discs while having the same dimensions.
Pre -recorded DVDs are
mass-produced using molding
machines that
physically stamp data onto the DVD. Such discs are a form of DVD-ROMs, because data can only be read and not written or
erased. Blank record able DVD discs (DVD-R and DVD+R) can be recorded once using a DVD recorder and then function as a
DVD-ROM. Re writable DVDs (DVD-RW, DVD+RW, and DVD-RAM) can be recorded and erased many times.
DVDs are used in DVD-Video consumer digital video format and in DVD-Audio consumer digital audio format as well as for
authoring DVD discs written in a special AVCHD format to hold high definition material DVDs containing other types of information may
be referred to as DVD data discs.
v iPad
iPad is a line of tablet computers designed,
developed and marketed by Apple Inc.,
which run the mobile operating system. The first iPad was released on April
3 .2010; the most recent iPad models are the 9.7-inch iPad Pro released on March
31, 2016 and the iPad Mini 4,
released on September 9, 2015. The user interface is built around
the device's multi-touchscreen,
including a virtual keyboard. The
iPad includes built-in Wi-Fi and cellular connectivity on
select models. As of January 2015, there have been over 250 million iPads sold.
v
HDTV
The term high
definition once described
a series of television systems originating from August 1936; however, these
systems were only high definition when compared to earlier systems that were
based on mechanical systems with as few as 30 lines of resolution. The ongoing
competition between companies and nations to create true "HDTV"
spanned the entire 20th century, as each new system became more HD than the
last. In the beginning of the 21st century, this race has continued with 4k, 5k
and current 8K systems.
v
Digital watch
A digital clock is a
type of clock that displays
the time digitally (i.e. in numerals or other symbols), as opposed to an analog clock, where the time is indicated by the positions of rotating
hands.
v
Digital Radio
Digital radio is the use of digital technology to transmit and/or
receive across the radio spectrum.
They may refer to digital
transmission by radio waves,
including digital
broadcasting, and especially to Digital
audio radio services .The term is
also applied to radio equipment using digital electronics to process analog radio signals.
v Digital Television
Digital television (DTV) is the transmission of audio and
video by digitally processed and multiplexed signal, in contrast to the totally
analog and channel separated signals used by analog television.
Digital TV can support more than one program in the same channel bandwidth. It is an
innovative service that represents the first significant evolution in
television technology since color television in the 1950s.
Several regions of the world are in different stages of adaptation and are
implementing different broadcasting standards. Below are the different widely
used digital television broadcasting standards .
v
CD player
A CD player is an electronic device that plays
audio compact discs,
which are a digital optical disc data storage format. CD players were first sold to consumers in 1982. CDs
typically contain recordings of audio material such as music. CD players are
often a part of home stereo systems, car audio systems, and personal computers. With
the exception of CD boomboxes, most CD players
do not produce sound by themselves. Most CD players only produce an output
signal via a headphone jack and/or RCA jacks. To listen to music using a CD
player with a headphone output jack, the
user plugs headphones or earphones into the headphone jack. To use a CD player
in a home stereo system, the user connects an RCA cable to the RCA jacks or other outputs
and connects it to a hi-fi (or other amplifier) and loudspeakers for listening to
music. They are also manufactured as portable devices, which are battery powered and typically used with
headphones.