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The experiment uses a simple barometer to measure the pressure of air, filling it with mercury up until 75% of the tube. Any air bubbles in the tube must be removed by inverting several times. After that, a clean mercury is filled once again until the tube is completely full. The barometer is then placed inverted on the dish full of mercury.
Later thermionic vacuum tubes, mostly miniature style, some with top cap connections for higher voltages. A vacuum tube, electron tube, [1] [2] [3] thermionic valve (British usage), or tube (North America) [4] is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied.
Examining the causes of the Great Depression raises multiple issues: what factors set off the first downturn in 1929; what structural weaknesses and specific events turned it into a major depression; how the downturn spread from country to country; and why the economic recovery was so prolonged.
The first prototype Fleming valves, built October 1904. Early commercial Fleming valves used in radio receivers, 1919 Fleming valve schematic from US Patent 803,684.. The Fleming valve, also called the Fleming oscillation valve, was a thermionic valve or vacuum tube invented in 1904 by English physicist John Ambrose Fleming as a detector for early radio receivers used in electromagnetic ...
This is a list of vacuum tubes or thermionic valves, and low-pressure gas-filled tubes, or discharge tubes. Before the advent of semiconductor devices, thousands of tube types were used in consumer electronics.
Differences explicitly pointed out between the recession and the Great Depression include the facts that over the 79 years between 1929 and 2008, great changes occurred in economic philosophy and policy, [9] the stock market had not fallen as far as it did in 1932 or 1982, the 10-year price-to-earnings ratio of stocks was not as low as in the ...
Vacuum-tube computers, now called first-generation computers, [1] are programmable digital computers using vacuum-tube logic circuitry. They were preceded by systems using electromechanical relays and followed by systems built from discrete transistors. Some later computers on the list had both vacuum tubes and transistors.
The San Francisco Bay area was one of the early centers of amateur radio activity and experimentation, containing about 10% of the total operators in the US. Amateur radio enthusiasts sought vacuum tubes that would perform at higher power and on higher frequencies than those then available from RCA, Western Electric, General Electric, and Westinghouse. [1]