File:Eilvese Goldschmidt alternator.jpg
From Wikimedia Commons, the free media repository
Jump to navigation
Jump to search
![File:Eilvese Goldschmidt alternator.jpg](https://upload.wikimedia.org/wikipedia/commons/thumb/b/b3/Eilvese_Goldschmidt_alternator.jpg/747px-Eilvese_Goldschmidt_alternator.jpg?20131005032120)
Size of this preview: 747 × 599 pixels. Other resolutions: 299 × 240 pixels | 598 × 480 pixels | 957 × 768 pixels | 1,276 × 1,024 pixels | 1,488 × 1,194 pixels.
Original file (1,488 × 1,194 pixels, file size: 543 KB, MIME type: image/jpeg)
File information
Structured data
Captions
Captions
Add a one-line explanation of what this file represents
Summary
[edit]DescriptionEilvese Goldschmidt alternator.jpg |
English: 100 kW Goldschmidt alternator at Eilvese, Germany. The Goldschmidt alternator, invented in 1908 by Rudolph Goldschmidt, was a rotating machine that generated high frequency alternating current, used as a radio transmitter from 1910 until about 1930. The Goldschmidt machine generates high frequencies without requiring excessive rotor speeds by using the rotor as a frequency multiplier as well as an AC generator. Tuned circuits called "reflector" circuits, attached to the stator and rotor (the capacitor banks against the walls) cause the machine to produce power at a harmonic (multiple) of the alternator frequency. In this machine, the 250 HP 220 VDC drive motor (left) turns the 3 ft diameter, 5 ton rotor (right) at 4000 RPM. The rotor has 360 narrow magnetic poles in its periphery, and therefore the fundamental frequency produced by the rotor is 24 kHz. The complicated reflector circuits cause the rotor to generate an alternating current at 4 times the fundamental frequency, 96 kHz, which is applied to the antenna through a transformer. The station transmitted text messages in Morse code, by the operator switching the DC power to the rotor on and off with a telegraph key. The machine was used for transatlantic wireless telegraphy traffic, exchanging messages with a similar
machine in Tuckerton, New Jersey, USA. Caption: Goldschmidt 100 K.W. radio frequency alternator |
Date | |
Source | Downloaded 4 October 2013 from Emil A. Mayer, "The Goldschmidt system of radio telegraphy", Proceedings of the IRE (Institute of Radio Engineers, New York), Vol. 2, No. 1, March 1914, p. 76, fig. 3 on Google Books |
Author | Emil A. Mayer |
Licensing
[edit]Public domainPublic domainfalsefalse |
![]() |
This media file is in the public domain in the United States. This applies to U.S. works where the copyright has expired, often because its first publication occurred prior to January 1, 1929, and if not then due to lack of notice or renewal. See this page for further explanation.
|
![]() |
![]() |
This image might not be in the public domain outside of the United States; this especially applies in the countries and areas that do not apply the rule of the shorter term for US works, such as Canada, Mainland China (not Hong Kong or Macao), Germany, Mexico, and Switzerland. The creator and year of publication are essential information and must be provided. See Wikipedia:Public domain and Wikipedia:Copyrights for more details.
|
File history
Click on a date/time to view the file as it appeared at that time.
Date/Time | Thumbnail | Dimensions | User | Comment | |
---|---|---|---|---|---|
current | 03:21, 5 October 2013 | ![]() | 1,488 × 1,194 (543 KB) | Chetvorno (talk | contribs) | User created page with UploadWizard |
You cannot overwrite this file.
File usage on Commons
There are no pages that use this file.
File usage on other wikis
The following other wikis use this file:
- Usage on ar.wikipedia.org
- Usage on de.wikipedia.org
- Usage on en.wikipedia.org
- Usage on fr.wikipedia.org
Metadata
This file contains additional information such as Exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file. The timestamp is only as accurate as the clock in the camera, and it may be completely wrong.
JPEG file comment | Created with GIMP |
---|