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866A
The 866 is a Mercury-arc valve, mercury vapor Rectifier#Half-wave rectification, half-wave rectifier intended for high-voltage applications. The voltage drop is approximately 15 volts up to 150 Hz. To avoid unwanted shorts the tube must be operated in a vertical position and the Heating element, filament preheated for at least 30 seconds before applying the plate voltage. Construction Structurally, it consists of a linear electrode arrangement; a cup shaped anode with top cap and a cylindrical cathode. The socket is a medium 4 pin bayonet Tube socket#Early bases, UX-4 and the glass envelope is ST-19. The 2.5 volt/ 5 Amp filament is connected to pins 1 and 4. Operation Under normal operating conditions the tube glows blue and mercury droplets are visible. Pictures in working conditions References Further reading * External links 866 @ The National Valve Museum [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tube Socket
Tube sockets are electrical sockets into which vacuum tubes (electronic valves) can be plugged, holding them in place and providing terminals, which can be soldered into the circuit, for each of the pins. Sockets are designed to allow tubes to be inserted in only one orientation. They were used in most tube electronic equipment to allow easy removal and replacement. When tube equipment was common, retailers such as drug stores had vacuum tube testers, and sold replacement tubes. Some Nixie tubes were also designed to use sockets. Throughout the tube era, as technology developed, sometimes differently in different parts of the world, many tube bases and sockets came into use. Sockets are not universal; different tubes may fit mechanically into the same socket, though they may not work properly and possibly become damaged. Tube sockets were typically mounted in holes on a sheet metal chassis and wires or other components were hand soldered to lugs on the underside of the socket. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diode
A diode is a two-terminal electronic component that conducts current primarily in one direction (asymmetric conductance); it has low (ideally zero) resistance in one direction, and high (ideally infinite) resistance in the other. A diode vacuum tube or thermionic diode is a vacuum tube with two electrodes, a heated cathode and a plate, in which electrons can flow in only one direction, from cathode to plate. A semiconductor diode, the most commonly used type today, is a crystalline piece of semiconductor material with a p–n junction connected to two electrical terminals. Semiconductor diodes were the first semiconductor electronic devices. The discovery of asymmetric electrical conduction across the contact between a crystalline mineral and a metal was made by German physicist Ferdinand Braun in 1874. Today, most diodes are made of silicon, but other semiconducting materials such as gallium arsenide and germanium are also used. Among many uses, diodes are found in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercury-arc Valve
A mercury-arc valve or mercury-vapor rectifier or (UK) mercury-arc rectifier is a type of electrical rectifier used for converting high-voltage or high-current alternating current (AC) into direct current (DC). It is a type of cold cathode gas-filled tube, but is unusual in that the cathode, instead of being solid, is made from a pool of liquid mercury and is therefore self-restoring. As a result mercury-arc valves, when used as intended, are far more robust and durable and can carry much higher currents than most other types of gas discharge tube. Some examples have been in continuous service, rectifying 50 ampere currents for decades. Invented in 1902 by Peter Cooper Hewitt, mercury-arc rectifiers were used to provide power for industrial motors, electric railways, streetcars, and electric locomotives, as well as for radio transmitters and for high-voltage direct current (HVDC) power transmission. They were the primary method of high power rectification before the advent of semi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rectifier
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The reverse operation (converting DC to AC) is performed by an Power inverter, inverter. The process is known as ''rectification'', since it "straightens" the direction of current. Physically, rectifiers take a number of forms, including Vacuum tube#Diodes, vacuum tube diodes, wet chemical cells, mercury-arc valves, stacks of copper and selenium rectifier, selenium oxide plates, Diode#Semiconductor diodes, semiconductor diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches. Historically, even synchronous electromechanical switches and motor-generator sets have been used. Early radio receivers, called crystal radios, used a "Cat's-whisker detector, cat's whisker" of fine wire pressing on a crystal of galena (lead sulfide) to serve as a point-contact rectifier or "crystal detec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-voltage
High voltage electricity refers to electrical potential large enough to cause injury or damage. In certain industries, ''high voltage'' refers to voltage above a certain threshold. Equipment and conductors that carry high voltage warrant special safety requirements and procedures. High voltage is used in electrical power distribution, in cathode ray tubes, to generate X-rays and particle beams, to produce electrical arcs, for ignition, in photomultiplier tubes, and in high-power amplifier vacuum tubes, as well as other industrial, military and scientific applications. Definition The numerical definition of depends on context. Two factors considered in classifying a voltage as high voltage are the possibility of causing a spark in air, and the danger of electric shock by contact or proximity. The International Electrotechnical Commission and its national counterparts (IET, IEEE, VDE, etc.) define ''high voltage'' as above 1000 V for alternating current, and at l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heating Element
A heating element converts electrical energy into heat through the process of Joule heating. Electric current through the element encounters resistance, resulting in heating of the element. Unlike the Peltier effect, this process is independent of the direction of current. Heating elements types Metal Resistance wire: Metallic resistance heating elements may be wire or ribbon, straight or coiled. They are used in common heating devices like toasters and hair dryers, furnaces for industrial heating, floor heating, roof heating, pathway heating to melt snow, dryers, etc. The most common classes of materials used include: * Nichrome: Most resistance wire heating elements usually use nichrome 80/20 (80% Nickel, 20% Chromium) wire, ribbon, or strip. Nichrome 80/20 is an ideal material, because it has relatively high resistance and forms an adherent layer of chromium oxide when it is heated for the first time. Material beneath this layer will not oxidize, preventing the wire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
