who invented moving coil galvanometer?

Answer 1

Jacques-Arsène d'Arsonval (June 8, 1851 - December 13, 1940) was born in La Porcherie and was a French biophysicist and inventor of the moving-coil galvanometer

Answer 2

From Wikipedia:
The term "galvanometer" derives from the surname of Luigi Galvani. Many early applications of galvanometers for measuring and recording are associated with William Thomson (Lord Kelvin). The earliest galvanometer was reported by Johann (Johan) Schweigger of Nuremberg at the University of Halle on 16th September 1820. André-Marie Ampère also contributed to the development of the galvanometer.

I haven't been able to determine if Schweigger's galvanometer was a moving coil or iron vane instrument.

The physicist Johann Salomo Christoph Schweigger is best known as the inventor of a device for measuring weak electric currents, the so-called multiplicator. From the 3rd reference, it appears to have been a moving coil instrument.

Answer 3

The Schweigger galvanometer had a fixed coil and moving magnet. The D'Arsonval galvanometer was the first with a fixed magnet and moving coil.

Answer 4

Who Invented The Coil

Answer 5

The guy credited with the invention was Johann Schweigger, in 1825.

Answer 6

The invention of the moving-coil galvanometer is credited to Johann Schweigger in 1825

The galvanometer, a device used to measure extremely small electrical currents, traces its origin back to 1820. In that year Hans Christian Oersted (1777-1851) discovered that an electric current flowing in a wire created a magnetic field around it, deflecting a magnetized needle. This effect became the basic principle behind the galvanometer. In the same year André Ampère (1775-1836) used the effect to invent a device to measure electric current. He suggested it be called the galvanometer, in honor of Luigi Galvani (1737-1798), a pioneer in the investigation of electricity.

The first practical use of the galvanometer was made by Karl Friedrich Gauss in 1832. Gauss built a telegraph that sent signals by deflecting a magnetic needle. This style is known as a moving-magnet galvanometer. More commonly used today is the moving-coil or moving-mirror galvanometer, sometimes called a D'Arsonval galvanometer.

The invention of the moving-coil galvanometer is credited to Johann Schweigger in 1825, three years later Italian physicist C. L. Nobilli designed an astatic type. It consists of a coil that has been wound with very fine wire mounted between the poles of a permanent magnet. Attached to the coil is a pointer. When electric current is turned on, the coil turns and the deflection angle is measured as the pointer moves along a graduated scale.

In the case of a moving-mirror galvanometer, a mirror is attached to the coil, and illuminated with light. When the coil moves the deflection of the light is measured along a scale. The mirror galvanometer was of major use in laying the transatlantic telegraph cable between the United States and Europe in 1866. William Thomson, later known as Lord Kelvin, used it to keep track of how much electric current was coursing through the cable. Thomson also invented a "siphon recorder," which was a more sensitive galvanometer. Ink was siphoned through a thin glass tube that was attached to the coil of wire which was mounted between the poles of a horseshoe magnet. The moving tube carried the ink onto a paper tape where it traced a line.

Galvanometers come in a variety of types. Ultraviolet recorders use light-sensitive paper and ultraviolet light in place of ink. A photoelectric galvanometer amplifies the signal using a photocell. The ballistic galvanometer is used to measure an electric pulse or burst. A cousin of the galvanometer is the direct current ammeter, which is a calibrated galvanometer that measures larger currents. Another cousin still is the direct-current voltmeter, which uses Ohm's Law to measure voltage. Digital display galvanometers, the best of which can measure a current as small as one hundredth billionth (10-11) of an amp, have almost entirely replaced the early analog galvanometers of yore.



Wíkipedia© on Galvanometer
It has been suggested that Tangent galvanometer be merged into this article or section. (Discuss)
Wire carrying current to be measured
Restoring springA galvanometer is an electromechanical transducer. It produces a rotary deflection, through a limited arc, in response to electric current flowing through its coil. The name galvanometer has been applied to devices used in measuring, recording, and positioning equipment.

Contents [hide]
1 Operation
2 Types
3 Uses
4 History
5 External link



Operation
The most familiar use is as an analog measuring instrument, often called a meter. It is used to measure the direct current (flow of electric charges) through an electric circuit. Such devices are constructed with a small pivoting coil of wire in the field of a permanent magnet. The coil is attached to a thin pointer that traverses a calibrated scale. A tiny spring pulls the coil and pointer to the zero position. In some meters, the magnetic field acts on a small piece of iron to perform the same effect as a spring.

When a direct current (DC) flows through the coil, the coil generates a magnetic field. This field acts with or against the permanent magnet. The coil pivots, pushing against the spring, and moving the pointer. The hand points at a scale indicating the electric current. A useful meter generally contains some provision for damping the mechanical resonance of the moving coil and pointer so that the pointer position smoothly tracks the current without excess vibration.


An automatic exposure unit from an 8 mm movie camera, based on a galvanometer mechanism (center) and a CdS photoresistor in the opening at left.The basic sensitivity of a meter might be, for instance, 100 microamperes full scale (with a voltage drop of, say, 50 millivolts at full current). Such meters are often calibrated to read some other quantity that can be converted to a current of that magnitude. The use of current dividers, often called shunts, allows a meter to be calibrated to measure larger currents. A meter can be calibrated as a DC voltmeter if the resistance of the coil is known by calculating the voltage required to generate a full scale current. A meter can be configured to read other voltages by putting it in a voltage divider circuit. This is generally done by placing a resistor in series with the meter coil. A meter can be used to read resistance by placing it in series with a known voltage (a battery) and an adjustable resistor. In a preparatory step, the circuit is completed and the resistor adjusted to produce full scale deflection. When an unknown resistor is placed in series in the circuit the current will be less than full scale and an appropriately calibrated scale can display the value of the previously-unknown resistor.

Because the pointer of the meter is usually a small distance above the scale of the meter, parallax error can occur when the operator attempts to read the scale line that "lines up" with the pointer. To counter this, some meters include a mirror along the markings of the principal scale. The accuracy of the reading from a mirrored scale is improved by moving the head while reading the scale so that the pointer and the reflection of the pointer are aligned; at this point, the operator's eye must be directly above the pointer and any parallax error has been minimized.


Types
Extremely sensitive measuring equipment once used mirror galvanometers that substituted a mirror for the pointer. A beam of light reflected from the mirror acted as a long, massless pointer. Such instruments were used as receivers for early trans-Atlantic telegraph systems, for instance. The moving beam of light could also be used to make a record on a moving photographic film, producing a graph of current versus time, in a device called an oscillograph.

Galvanometer mechanisms are used to position the pens of analog chart recorders such as used for making an electrocardiogram. Strip chart recorders with galvanometer driven pens might have a full scale frequency response of 100 Hz and several centimeters deflection. In some cases (the classical polygraph of movies or the electroencephalograph), the galvanometer is strong enough to move the pen while it remains in contact with the paper; the writing mechanism may be a heated tip on the needle writing on heat-sensitive paper or a fluid-fed pen. In other cases (the Rustrak recorders), the needle is only intermittently pressed against the writing medium; at that moment, an impression is made and then the pressure is removed, allowing the needle to move to a new position and the cycle repeats. In this case, the galvanometer need not be especially strong.


Uses
Mirror galvanometer systems are used as beam positioning elements in laser optical systems. These are typically high power galvanometer mechanisms used with closed loop servo control systems. They can have frequency responses over 1 kHz.

Galvanometers have been replaced as measuring instruments by analog to digital converters (ADC) for most uses. There are, for instance, self contained digital measuring systems, called digital panel meters (DPMs), available to replace most traditional analog meter functions. Many computer systems also employ ADC's


History
The term "galvanometer" derives from the surname of Luigi Galvani. Many early applications of galvanometers for measuring and recording are associated with William Thomson (Lord Kelvin). The earliest galvanometer was reported by Johann (Johan) Schweigger of Nuremberg at the University of Halle on 16th September 1820. André-Marie Ampère also contributed to the development of the galvanometer.

Answer 7

The MCG was invented by Micheal Faraday The other versions of the MCG were invented later by scientists such as Thomas Alva Edison and Ampere