File:Goldschmidt alternator at Eilvese Germany 1928.jpg
Size of this preview: 800 × 531 pixels. Other resolutions: 320 × 212 pixels | 640 × 425 pixels | 866 × 575 pixels.
Original file (866 × 575 pixels, file size: 177 KB, MIME type: image/jpeg)
 | This is a file from the Wikimedia Commons. Information from its description page there is shown below. Commons is a freely licensed media file repository. You can help. |
Summary
| Description |
English: A 200 kilowatt Goldschmidt alternator radio transmitter at Eilvese, Germany, in 1928. Alternator radio transmitters like this were used in high power transoceanic very low frequency radiotelegraphy stations for a short time from about 1915 to 1930. It consists of a 250 HP electric motor (left) turning an alternating current generator (alternator) (right) consisting of a rotor with wire windings turning inside a stator with wire windings. The rotor has 400 poles and turns at 3750 RPM, so it generates an alternating current at 12.5 kHz. The capacitors and coils at top attached to the rotor, called reflector circuits, interact with the iron rotor to create a harmonic at 4 times the fundamental frequency or 50 kHz, which is applied to the antenna.
A very similar photo of this machine was published in Science and Invention, Experimenter Publishing Co., New York, Vol.8, No.8, December 1920, p.881 so it was installed prior to December 1920. |
| Date | |
| Source | Retrieved 13 October 2024 from Lionel Stanley Palmer (1928) Wireless Principles and Practice, Longmans, Green and Co., New York, p.189, fig.115 on Google Books |
| Author | Lionel Stanley Palmer |
Licensing
|
This work is in the public domain in the United States because it was published (or registered with the U.S. Copyright Office) before January 1, 1929.
 Public domain works must be out of copyright in both the United States and in the source country of the work in order to be hosted on the Commons. If the work is not a U.S. work, the file must have an additional copyright tag indicating the copyright status in the source country.
Note: This tag should not be used for sound recordings. |
File history
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 09:15, 14 October 2024 | | 866 × 575 (177 KB) | Chetvorno | Uploaded a work by Lionel Stanley Palmer from Retrieved 13 October 2024 from [https://books.google.com/books?id=mHxBAAAAIAAJ&pg=PA189 Lionel Stanley Palmer (1928) ''Wireless Principles and Practice'', Longmans, Green and Co., New York, p.189, fig.115] on Google Books with UploadWizard |
File usage
The following page uses this file:
