File:Dolbear's wireless telephone circuit 1886.png
Dolbear's_wireless_telephone_circuit_1886.png (584 × 325 pixels, file size: 15 KB, MIME type: image/png)
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DescriptionDolbear's wireless telephone circuit 1886.png |
English: Circuit diagram of experimental wireless telephone patented by Prof. Amos Dolbear in 1883, from an 1886 article in Scientific American. The transmitter (A) consisted of an electrostatic microphone (T) and battery in the primary circuit of an induction coil (G). One side of the high voltage secondary winding is earthed (C) the other side connected to an elevated metal sheet capacitance (H1). The receiver (B) consists of a battery, earphone (R) and capacitor (H) connected in series between an elevated capacitive plate (H2) and earth (D). It was compared to the first true radio communication system invented by Guglielmo Marconi in 1884, but Dolbear's system worked by electrostatic induction, not radio waves, and he couldn't communicate further than about a quarter mile. Later Dolbear replaced the capacitors with kite-suspended wire antennas and probably transmitted radio waves, achieving longer distances. In 1899 a New England telephone company bought Dolbear's 1883 patent and sued Marconi (who had patented his system a year later) for infringement, but the suit was dismissed in 1901. |
Date | |
Source | Retrieved 29 April 2024 from Dolbear, A. E. "Electric communication without wires" in Scientific American Supplement, Munn and Co., Vol.22, No.571, 11 December 1886, p.9119 on archive.org. Original source US Patent 350299A, Amos Emerson Dolbear, Mode of electric communication, applied 24 March 1882, granted 5 October 1886 |
Author | Amos E. Dolbear |
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current | 21:59, 29 April 2024 | 584 × 325 (15 KB) | Chetvorno (talk | contribs) | Uploaded a work by Amos E. Dolbear from [https://archive.org/details/sim_scientific-american-supplement_1886-12-11_22_571/page/9118/mode/2up Dolbear, A. E. Electric communication without wires in Scientific American Supplement, Munn and Co., Vol.22, No.571, 11 December 1886, p.9119] on archive.org with UploadWizard |
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File change date and time | 20:53, 29 April 2024 |