After further investivation while working for the Marconi Wireless Telegraph Co ., Ltd ., Fleming patented the Fleming Valve rectifier in 1904, resulting in the electron tube becoming the basis of modern electronics.
12.
However, to many observers it appeared that de Forest had done nothing more than add the grid electrode to an existing detector configuration, the Fleming valve, which also consisted of a filament and plate enclosed in an evacuated glass tube.
13.
Other radio detectors invented for wireless telegraphy, such as the Fleming valve ( 1904 ) and the crystal detector ( 1906 ) also proved able to rectify AM signals, so the technological hurdle was generating AM waves; receiving them was not a problem.
14.
De Forest continued to claim that he developed the Audion independently from John Ambrose Fleming's earlier research on the thermionic valve ( for which he received Great Britain patent 24850 and the American Fleming valve patent ( ), and became embroiled in many radio-related patent disputes.
15.
Because the " damped waves " are a train of regularly spaced radio frequency triangle waves that occur at an audio rate, early crystal, magnetic and Fleming valve detectors heard them as a musical note, rich in harmonics, making it easy for the human ear to " copy " messages and identify stations by their unique sound, even under adverse conditions.
16.
The problem was that ( possibly to distance his invention from the Fleming valve ) De Forest's original patents specified that low-pressure gas inside the Audion was essential to its operation ( Audion being a contraction of " Audio-Ion " ), and in fact early Audions had severe reliability problems due to this gas being adsorbed by the metal electrodes.
17.
The "'Fleming valve "', also called the "'Fleming oscillation valve "', was a vacuum tube ( or " thermionic valve " ) invented in 1904 by John Ambrose Fleming as a power supplies of a wide range of electronic devices, until beginning to be replaced by the selenium rectifier in the early 1930s and almost completely replaced by the semiconductor diode in the 1960s.
18.
De Forest passionately denied the similarly of the two devices, claiming his invention was a relay that amplified currents, while the Fleming valve was merely a rectifier that converted alternating current to direct current . ( For this reason, de Forest objected to his Audion being referred to as " a valve " . ) The U . S . courts were not convinced, and ruled that the grid Audion did in fact infringe on the Fleming valve patent, now held by Marconi.
19.
De Forest passionately denied the similarly of the two devices, claiming his invention was a relay that amplified currents, while the Fleming valve was merely a rectifier that converted alternating current to direct current . ( For this reason, de Forest objected to his Audion being referred to as " a valve " . ) The U . S . courts were not convinced, and ruled that the grid Audion did in fact infringe on the Fleming valve patent, now held by Marconi.
