Editing Talk:2642: Meta-Alternating Current
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Long distance links, especially those between separate unsynchronized grids, use high voltage DC. There is a 2,000-mile link in China running at 1 MV. [[User:Arachrah|Arachrah]] ([[User talk:Arachrah|talk]]) 11:32, 7 July 2022 (UTC) | Long distance links, especially those between separate unsynchronized grids, use high voltage DC. There is a 2,000-mile link in China running at 1 MV. [[User:Arachrah|Arachrah]] ([[User talk:Arachrah|talk]]) 11:32, 7 July 2022 (UTC) | ||
:That's because at great distances, relatively high frequency AC loses a lot of ("active" = actually useful) power as ... reactive power, I think (didn't learn the terminology in English, unit seems right though). A typical grid has a lot of generators and load. A long distance connection results in a phase shift according to the transmission time (speed of light in medium x distance) in about the order of magnitude of the AC period (usually somewhere between 1/10 to 1/60 seconds) wastes a portion equal to the sine of the phase shift angle (up to 90° = all of it) as reactive power. DC isn't quite as easy to use but on long distances there is no power loss to reactive power. [[User:627235|627235]] ([[User talk:627235|talk]]) 12:25, 7 July 2022 (UTC) | :That's because at great distances, relatively high frequency AC loses a lot of ("active" = actually useful) power as ... reactive power, I think (didn't learn the terminology in English, unit seems right though). A typical grid has a lot of generators and load. A long distance connection results in a phase shift according to the transmission time (speed of light in medium x distance) in about the order of magnitude of the AC period (usually somewhere between 1/10 to 1/60 seconds) wastes a portion equal to the sine of the phase shift angle (up to 90° = all of it) as reactive power. DC isn't quite as easy to use but on long distances there is no power loss to reactive power. [[User:627235|627235]] ([[User talk:627235|talk]]) 12:25, 7 July 2022 (UTC) | ||
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Let's face it, the thing should be called an alternator. Of course that name's taken as a redundant word for (electrical) generator. [[User:627235|627235]] ([[User talk:627235|talk]]) 12:26, 7 July 2022 (UTC) | Let's face it, the thing should be called an alternator. Of course that name's taken as a redundant word for (electrical) generator. [[User:627235|627235]] ([[User talk:627235|talk]]) 12:26, 7 July 2022 (UTC) | ||
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:: The mains input bridge rectifier in every PSU I've seen is just a normal 4 diode bridge, it's at worst a 2% loss. The output from the transformer probably has synchronous rectification due to the much lower voltage, but not an H-bridge, instead a center-tapped transformer winding and 2 MOSFETs. The only H-bridge in a PSU is the inverter. [[Special:Contributions/141.101.76.233|141.101.76.233]] 21:43, 8 July 2022 (UTC) | :: The mains input bridge rectifier in every PSU I've seen is just a normal 4 diode bridge, it's at worst a 2% loss. The output from the transformer probably has synchronous rectification due to the much lower voltage, but not an H-bridge, instead a center-tapped transformer winding and 2 MOSFETs. The only H-bridge in a PSU is the inverter. [[Special:Contributions/141.101.76.233|141.101.76.233]] 21:43, 8 July 2022 (UTC) | ||
::: Please see https://www.physics-and-radio-electronics.com/electronic-devices-and-circuits/rectifier/bridgerectifier.html "The maximum rectifier efficiency of a bridge rectifier is 81.2% which is same as the center tapped full wave rectifier." See also https://techweb.rohm.com/knowledge/acdc/acdc_pwm/acdc_pwm06/8786 [[Special:Contributions/162.158.166.183|162.158.166.183]] 19:36, 16 July 2022 (UTC) | ::: Please see https://www.physics-and-radio-electronics.com/electronic-devices-and-circuits/rectifier/bridgerectifier.html "The maximum rectifier efficiency of a bridge rectifier is 81.2% which is same as the center tapped full wave rectifier." See also https://techweb.rohm.com/knowledge/acdc/acdc_pwm/acdc_pwm06/8786 [[Special:Contributions/162.158.166.183|162.158.166.183]] 19:36, 16 July 2022 (UTC) | ||
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I interpreted Randall imagining "inversion" as "reciprocal" (or maybe the inversion of a function) rather than physically turning something upside-down, since mathematical inversion is typically reversible... [[Special:Contributions/172.70.130.121|172.70.130.121]] 03:48, 8 July 2022 (UTC) | I interpreted Randall imagining "inversion" as "reciprocal" (or maybe the inversion of a function) rather than physically turning something upside-down, since mathematical inversion is typically reversible... [[Special:Contributions/172.70.130.121|172.70.130.121]] 03:48, 8 July 2022 (UTC) | ||
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::: The comic is about "meta alternating" pairs of consumer inverters and rectifiers, not idealized chains of the same circuit. [[Special:Contributions/172.70.206.213|172.70.206.213]] 00:58, 9 July 2022 (UTC) | ::: The comic is about "meta alternating" pairs of consumer inverters and rectifiers, not idealized chains of the same circuit. [[Special:Contributions/172.70.206.213|172.70.206.213]] 00:58, 9 July 2022 (UTC) | ||
:::: The title text is about pairing two inverters and having them cancel each other out. It's relevant. [[User:SwervingLemon|SwervingLemon]] ([[User talk:SwervingLemon|talk]]) 19:33, 9 July 2022 (UTC) | :::: The title text is about pairing two inverters and having them cancel each other out. It's relevant. [[User:SwervingLemon|SwervingLemon]] ([[User talk:SwervingLemon|talk]]) 19:33, 9 July 2022 (UTC) | ||
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