Analog device
Encyclopedia
Analog device is an apparatus
that measure
s continuous information
. The measured analog signal
has an infinite number of possible value
s. The only limitation on resolution
is the accuracy of the measuring device. Such apparatus operates with variables which are constituted by continuously measured quantities. These quantities can be voltage
, resistance
, rotation
and pressure
.
is an analogue precursor to the modern fax machine. Basically it transmits electrical impulses recorded by potentiometers to stepping motors attached to a pen, thus being able to reproduce a drawing or signature made by the sender at the receiver's station. It was the first such device to transmit drawings to a stationary sheet of paper; previous inventions in Europe used rotating drums to make such transmissions.
An analog synthesizer
is a synthesizer that uses analog circuits and analog computer
techniques to generate sound electronically.
The analog television
encodes television and transports the picture and sound information as an analogue signal, that is, by varying the amplitude and/or frequencies of the broadcast signal. All systems preceding digital television, such as NTSC, PAL or SECAM are analog television systems.
An analog computer
is a form of computer that uses electrical, mechanical or hydraulic phenomena to model the problem being solved. More generally an analog computer uses one kind of physical quantity to represent the behaviour of another physical system, or mathematical function. Modeling a real physical system in a computer is called simulation.
There are also many non-electrical analog devices, such as clocks (sundials, water clocks, pendulum clocks, analog watches), the astrolabe, slide rules, the governor of a steam engine, the planimeter (a simple device that measures the area of a closed shape), Kelvin's mechanical tide predictor, acoustic rangefinders, servomechanisms (e.g. the thermostat), a simple mercury thermometer, a bathroom scale, and the speedometer of a car.
(DAC or D-to-A) is a circuit for converting a digital signal
(usually binary) to an analog signal (current, voltage or electric charge). Digital-to-analog converters are interfaces between the digital world and analog world. An analog-to-digital converter
(abbreviated ADC, A/D or A to D) is an electronic circuit that converts continuous signals to discrete digital numbers. The reverse operation is performed by a digital-to-analog converter
(DAC).
Machine
A machine manages power to accomplish a task, examples include, a mechanical system, a computing system, an electronic system, and a molecular machine. In common usage, the meaning is that of a device having parts that perform or assist in performing any type of work...
that measure
Measure
- Legal :* Measure of the Church of England is a law passed by the General Synod and the UK Parliament equivalent of an Act* Measure of the National Assembly for Wales, a law specific to Wales passed by the Welsh Assembly between 2007 and 2011...
s continuous information
Information
Information in its most restricted technical sense is a message or collection of messages that consists of an ordered sequence of symbols, or it is the meaning that can be interpreted from such a message or collection of messages. Information can be recorded or transmitted. It can be recorded as...
. The measured analog signal
Analog signal
An analog or analogue signal is any continuous signal for which the time varying feature of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal. It differs from a digital signal in terms of small fluctuations in the signal which are...
has an infinite number of possible value
Value (mathematics)
In mathematics, value commonly refers to the 'output' of a function. In the most basic case, that of unary, single-valued functions, there is one input and one output .The function f of the example is real-valued, since each and every possible function value is real...
s. The only limitation on resolution
Angular resolution
Angular resolution, or spatial resolution, describes the ability of any image-forming device such as an optical or radio telescope, a microscope, a camera, or an eye, to distinguish small details of an object...
is the accuracy of the measuring device. Such apparatus operates with variables which are constituted by continuously measured quantities. These quantities can be voltage
Voltage
Voltage, otherwise known as electrical potential difference or electric tension is the difference in electric potential between two points — or the difference in electric potential energy per unit charge between two points...
, resistance
Electrical resistance
The electrical resistance of an electrical element is the opposition to the passage of an electric current through that element; the inverse quantity is electrical conductance, the ease at which an electric current passes. Electrical resistance shares some conceptual parallels with the mechanical...
, rotation
Rotation
A rotation is a circular movement of an object around a center of rotation. A three-dimensional object rotates always around an imaginary line called a rotation axis. If the axis is within the body, and passes through its center of mass the body is said to rotate upon itself, or spin. A rotation...
and pressure
Pressure
Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
.
Examples
The telautographTelautograph
The telautograph, an analog precursor to the modern fax machine, transmits electrical impulses recorded by potentiometers at the sending station to servomechanisms attached to a pen at the receiving station, thus reproducing at the receiving station a drawing or signature made by the sender...
is an analogue precursor to the modern fax machine. Basically it transmits electrical impulses recorded by potentiometers to stepping motors attached to a pen, thus being able to reproduce a drawing or signature made by the sender at the receiver's station. It was the first such device to transmit drawings to a stationary sheet of paper; previous inventions in Europe used rotating drums to make such transmissions.
An analog synthesizer
Analog synthesizer
An analog or analogue synthesizer is a synthesizer that uses analog circuits and analog computer techniques to generate sound electronically. The earliest analog synthesizers in the 1920s and 1930s such as the Trautonium were built with a variety of vacuum-tube and electro-mechanical technologies...
is a synthesizer that uses analog circuits and analog computer
Analog computer
An analog computer is a form of computer that uses the continuously-changeable aspects of physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved...
techniques to generate sound electronically.
The analog television
Analog television
Analog television is the analog transmission that involves the broadcasting of encoded analog audio and analog video signal: one in which the message conveyed by the broadcast signal is a function of deliberate variations in the amplitude and/or frequency of the signal...
encodes television and transports the picture and sound information as an analogue signal, that is, by varying the amplitude and/or frequencies of the broadcast signal. All systems preceding digital television, such as NTSC, PAL or SECAM are analog television systems.
An analog computer
Analog computer
An analog computer is a form of computer that uses the continuously-changeable aspects of physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved...
is a form of computer that uses electrical, mechanical or hydraulic phenomena to model the problem being solved. More generally an analog computer uses one kind of physical quantity to represent the behaviour of another physical system, or mathematical function. Modeling a real physical system in a computer is called simulation.
There are also many non-electrical analog devices, such as clocks (sundials, water clocks, pendulum clocks, analog watches), the astrolabe, slide rules, the governor of a steam engine, the planimeter (a simple device that measures the area of a closed shape), Kelvin's mechanical tide predictor, acoustic rangefinders, servomechanisms (e.g. the thermostat), a simple mercury thermometer, a bathroom scale, and the speedometer of a car.
Interfacing the digital and analog worlds
In electronics, a digital-to-analog converterDigital-to-analog converter
In electronics, a digital-to-analog converter is a device that converts a digital code to an analog signal . An analog-to-digital converter performs the reverse operation...
(DAC or D-to-A) is a circuit for converting a digital signal
Digital signal
A digital signal is a physical signal that is a representation of a sequence of discrete values , for example of an arbitrary bit stream, or of a digitized analog signal...
(usually binary) to an analog signal (current, voltage or electric charge). Digital-to-analog converters are interfaces between the digital world and analog world. An analog-to-digital converter
Analog-to-digital converter
An analog-to-digital converter is a device that converts a continuous quantity to a discrete time digital representation. An ADC may also provide an isolated measurement...
(abbreviated ADC, A/D or A to D) is an electronic circuit that converts continuous signals to discrete digital numbers. The reverse operation is performed by a digital-to-analog converter
Digital-to-analog converter
In electronics, a digital-to-analog converter is a device that converts a digital code to an analog signal . An analog-to-digital converter performs the reverse operation...
(DAC).