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The first electric-powered torque amplifier was invented in 1925 by Henry W. Nieman of the Bethlehem Steel Company of Bethlehem, Pennsylvania. [1] It was intended to allow manual control of heavy equipment; e.g., industrial cranes, artillery, etc. Vannevar Bush used Nieman's torque amplifier as part of his differential analyzer project at M.I.T in the early 1930s. [2]
In Australia and New Zealand, the terminology is different. A "phase" is a period of time during which a set of traffic movements receive a green signal - equivalent to the concept of a "stage" in UK and US. One electrical output from the traffic signal controller is called a "signal group" - similar to the UK and US concept of "phase".
Costing one penny, the first edition of the code was published on 14 April 1931. It contained 21 pages of advice, including the arm signals to be given by drivers and police officers controlling traffic. [4] The second edition, considerably expanded, appeared in 1934, and now illustrated road signs for the first time.
IAM RoadSmart, formerly called the Institute of Advanced Motorists (IAM), is a charity based in the United Kingdom, whose objective is to improve car driving standards, motorcycle riding standards, and enhance road safety by using the British police's system of car and motorcycle control.
Paul Voigt patented a negative feedback amplifier in January 1924, though his theory lacked detail. [4] Harold Stephen Black independently invented the negative-feedback amplifier while he was a passenger on the Lackawanna Ferry (from Hoboken Terminal to Manhattan) on his way to work at Bell Laboratories (located in Manhattan instead of New Jersey in 1927) on August 2, 1927 [5] (US Patent ...
A valve RF amplifier (UK and Aus.) or tube amplifier is a device for electrically amplifying the power of an electrical radio frequency signal. Low to medium power valve amplifiers for frequencies below the microwaves were largely replaced by solid state amplifiers during the 1960s and 1970s, initially for receivers and low power stages of ...
The first such systems were installed on an experimental basis in the 1910s in the United Kingdom, in the 1920s in the United States, and in the Netherlands in the 1940s. . Modern high-speed rail systems such as those in Japan, France, and Germany were all designed from the start to use in-cab signalling due to the impracticality of sighting wayside signals at the new higher train spee
A traveling-wave tube (TWT, pronounced "twit" [1]) or traveling-wave tube amplifier (TWTA, pronounced "tweeta") is a specialized vacuum tube that is used in electronics to amplify radio frequency (RF) signals in the microwave range. [2]