File:EB1911 Telegraph - Marconi magnetic detector.jpg
From Wikimedia Commons, the free media repository
Jump to navigation
Jump to search
EB1911_Telegraph_-_Marconi_magnetic_detector.jpg (370 × 319 pixels, file size: 22 KB, MIME type: image/jpeg)
File information
Structured data
Captions
Captions
Add a one-line explanation of what this file represents
DescriptionEB1911 Telegraph - Marconi magnetic detector.jpg |
English: In 1902 Marconi invented two forms of magnetic detector, one of which he developed into an electric wave detector of extraordinary delicacy and utility (see Proc. Roy. Soc., 1902, 70, p. 341, or British Pat. Spec. No. 10245 of 1902). In this last form an endless band of hard iron wires passes slowly round two wooden pulleys driven by clockwork. In its course it passes through a glass tube wound over with two coils of wire; one of these is an oscillation coil through which the oscillations to be detected pass, and the other is in connexion with a telephone. Two horse-shoe magnets are so placed (see figure) that they magnetize the part of the iron band passing through the coil. Owing to hysteresis the part of the band magnetized is not symmetrically placed with regard to the magnetic poles, but advanced in the direction of motion of the band. When the oscillations pass through the coil they annul the hysteresis and cause a change of magnetism within the coil connected to the telephone. This creates a short sound in the telephone. Hence according as the trains of oscillations are long or short so is the sound heard in the telephone, and these sounds can be arranged on the Morse code into alphabetic audible signals. When used as a receiver for wireless telegraphy Marconi inserted the oscillation coil of this detector in between the earth and a receiving antenna, and this produced one of the most sensitive receivers yet made for wireless telegraphy. |
||||
Date | published 1911 | ||||
Source | Encyclopædia Britannica (11th ed.), v. 26, 1911, “Telegraph,” p. 536, Fig. 45. | ||||
Author | Guglielmo Marconi | ||||
Permission (Reusing this file) |
|
File history
Click on a date/time to view the file as it appeared at that time.
Date/Time | Thumbnail | Dimensions | User | Comment | |
---|---|---|---|---|---|
current | 17:09, 22 March 2016 | 370 × 319 (22 KB) | Library Guy (talk | contribs) | {{Information |Description ={{en|1=In 1902 Marconi invented two forms of magnetic detector, one of which he developed into an electric wave detector of extraordinary delicacy and utility (see ''Proc. Roy. Soc.'', 1902, 70, p. 341, or British Pat. Sp... |
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 en.wikisource.org