|
The arc converter, sometimes called the arc transmitter or Poulsen arc after its inventor Valdemar Poulsen, is a device used to convert DC energy into RF energy. Valdemar Poulsen ( November 23, 1869, in Copenhagen – July 23, 1942) was a Danish Engineer. Direct current ( DC) is the unidirectional flow of Electric charge. Radio frequency ( RF) is a Frequency or rate of Oscillation within the range of about 3 Hz to 300 GHz It is now on the list of IEEE Milestones as a historic achievement in electrical engineering. This list of IEEE Milestones describes the Institute of Electrical and Electronics Engineers (IEEE milestones representing key historical achievements in electrical and electronic Electrical engineering, sometimes referred to as electrical and electronic engineering, is a field of Engineering that deals with the study and application of
History
The English engineer William Duddell discovered how to make a resonant circuit using a carbon arc lamp. An LC circuit is a variety of resonant circuit or tuned circuit and consists of an Inductor, represented by the letter L and a Capacitor, represented Duddell's "musical arc" operated at audio frequencies, and Duddell himself concluded that it was impossible to make the arc oscillate at radio frequencies. An audio frequency (abbreviation AF) or audible frequency is characterized as a periodic vibration whose Frequency is audible to the average human Radio frequency ( RF) is a Frequency or rate of Oscillation within the range of about 3 Hz to 300 GHz
Valdemar Poulsen, who had demonstrated the 'Telegraphone' (the world's first magnetic recording device) at the Paris Exhibition of 1900, turned his inventive genius to the problem and succeeded in raising the efficiency and frequency to the desired level; Poulsen's arc could generate frequencies of up to 200 kilohertz and was patented in 1903. Valdemar Poulsen ( November 23, 1869, in Copenhagen – July 23, 1942) was a Danish Engineer. Magnetic storage and magnetic recording are terms from Engineering referring to the storage of Data on a Magnetized medium The Exposition Universelle of 1900 was a World's fair held in Paris, France, to celebrate the achievements of the past century and to accelerate Frequency is a measure of the number of occurrences of a repeating event per unit Time. The hertz (symbol Hz) is a measure of Frequency, informally defined as the number of events occurring per Second. Year 1903 ( MCMIII) was a Common year starting on Thursday (link will display calendar of the Gregorian calendar or a Common year starting
After a few years of development the arc technology was transferred to Germany and Great Britain in 1906 by Poulsen, his collaborator Peder Oluf Pedersen and their financial backers. Technology is a broad concept that deals with a Species ' usage and knowledge of Tools and Crafts and how it affects a species' ability to control and adapt Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. See also Kingdom of Great Britain Great Britain (Breatainn Mhòr Prydain Fawr Breten Veur Graet Breetain is the larger of the two main islands Peder Oluf Pedersen ( June 19, 1874 – August 30, 1941) was a Danish Engineer and Physicist. In 1909 the American patents as well as a few arc converters were bought by Cyril F. Elwell. The subsequent development in Europe and the United States was rather different, since in Europe there were severe difficulties for many years implementing the Poulsen technology, whereas in the United States an extended commercial radiotelegraph system was soon established. The United States of America —commonly referred to as the Later the US Navy also adopted the Poulsen system. Only the arc converter with passive frequency conversion was suitable for portable and maritime use. This made it the most important mobile radio system for about a decade until it was superseded by vacuum tube systems. This article is about professional equipment For mobile radios used in Amateur radio, see Amateur radio mobile operation. This article is about the electronic device not an evacuated pipe used for experiments in Free-fall.
Description
Unlike the spark-gap transmitter converter, the arc converter produces undamped or continuous waves (CW), This was an important feature as the use of damped waves resulted in lower transmitter efficiency and communications effectiveness, while covering the r. A spark-gap transmitter is a device for generating Radio frequency electromagnetic waves. A continuous wave or continuous waveform ( CW) is an Electromagnetic wave of constant Amplitude and Frequency; and in Mathematical A damped wave is an electromagnetic wave whose Amplitude of Oscillation decreases with time eventually going to zero f. spectrum with interference. This more refined method for generating continuous-wave radio signals was initially developed by Danish inventor Valdemar Poulsen. Valdemar Poulsen ( November 23, 1869, in Copenhagen – July 23, 1942) was a Danish Engineer. The Poulsen arc converter can be likened to a continuous-duty-rated electric arc welder with a tuned circuit connected across the arc. Arc welding uses a Welding power supply to create an Electric arc between an electrode and the base material to melt the metals at the welding point An LC circuit is a variety of resonant circuit or tuned circuit and consists of an Inductor, represented by the letter L and a Capacitor, represented The negative resistance characteristics of an electric arc permits the creation of a relaxation oscillator that converts direct current to radio frequency energy. Negative resistance (or negative differential resistance (NDR or differential negative resistance (DNR is a property of Electrical circuit elements composed An electric arc is an Electrical breakdown of a gas which produces an ongoing plasma discharge, resulting from a current flowing through normally nonconductive A relaxation oscillator is an oscillator in which a Capacitor is charged gradually and then discharged rapidly Direct current ( DC) is the unidirectional flow of Electric charge. Radio frequency ( RF) is a Frequency or rate of Oscillation within the range of about 3 Hz to 300 GHz The arc converter consisted of a water-cooled bronze chamber in which the arc burned in hydrogen gas between a carbon cathode and a water-cooled copper anode. Bronze is any of a broad range of Copper alloys, usually with Tin as the main additive but sometimes with other elements such as Phosphorus Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 A cathode is an Electrode through which (positive Electric current flows out of a polarized electrical device Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 An anode is an Electrode through which Electric current flows into a polarized electrical device Above and below this chamber there were two series field coils surrounding and energizing the two poles of the magnetic circuit. A field coil is the magnetic field component of an alternator generator dynamo motor or rotary converter These poles projected into the chamber, one on each side of the arc to provide a magnetic field. In Physics, a magnetic field is a Vector field that permeates space and which can exert a magnetic force on moving Electric charges This field helps to stabilize the arc and improve overall conversion efficiency. In today's world one still find oscillators based on negative resistance devices; the tunnel diode is one of them. Oscillation is the repetitive variation typically in Time, of some measure about a central value (often a point of Equilibrium) or between two or more different states A tunnel Diode or Esaki diode is a type of Semiconductor diode which is capable of very fast operation well into the Microwave frequency
Since the arc took some time to strike and operate in a stable fashion, normal on-off keying could not be used. On-off keying ( OOK) is a type of Modulation that represents Digital Data as the presence or absence of a Carrier wave. Instead, a form of frequency shift keying was employed. Frequency-shift keying (FSK is a Frequency modulation scheme in which digital information is transmitted through discrete frequency changes of a Carrier wave The arc was left operating continuously and a portion of the tuned circuit was shorted out when the key closed. An LC circuit is a variety of resonant circuit or tuned circuit and consists of an Inductor, represented by the letter L and a Capacitor, represented Therefore, the "mark" (key closed) was sent at one frequency; the "space" (key open) at another frequency. If these frequencies were far enough apart, and the receiving station's receiver had adequate selectivity, the receiving station would hear standard CW when tuned to the "mark" frequency. This emission of signals at two differing frequencies was eliminated by the development of uniwave keying by Lt. W. A. Eaton, USN. wherein the generated energy was dissipated in to a noninductive resistive absorbing circuit during open key periods. |- align = "center"| |width = "25"| | |- align = "center"| || Potentiometer |- align = "center"| | | |- align = "center"| Resistor| |
It was most successful when made to operate in the frequency range of a few kilohertz to a few tens of kilohertz. The hertz (symbol Hz) is a measure of Frequency, informally defined as the number of events occurring per Second. The passive frequency multiplier was relied upon to bring the output frequency up to practical transmission frequencies. The frequency multiplier and antenna tuning had to be selective enough to suppress the high harmonic output of the arc converter. An antenna tuner, transmatch or antenna tuning unit (ATU matches a transceiver with a fixed impedance (typically 50 Ohms for modern transceivers to a load (feed In Acoustics and Telecommunication, the harmonic of a Wave is a component Frequency of the signal that is an Integer
See also
References
- Principles of Radio Communication, Morecroft JH, Pinto A & Curry WA; John Wiley & Sons Inc (New York), 1921. The pre-history and early history of radio is the history of Technology that produced radio instruments that use Radio waves Within the Timeline of For biologic transmitters see Transmitter substance. A transmitter is an electronic device which usually with the aid of an antenna
- History of Communications-Electronics in the United States Navy, Captain Linwood S. Howeth, USN (Retired), U. S. Govt. Print. Office, 1963
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic