Editing 2642: Meta-Alternating Current

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==Explanation==
 
==Explanation==
This is the sixth installment in the series of [[:Category:Cursed Connectors|Cursed Connectors]] and presents Cursed Connectors #120: Meta-alternating current extension cord.  
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{{incomplete|Created by a CHAIN OF INVERTERS - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
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This comic replaced [[No One Was Hurt]] as comic 2642 after the former was taken down from [[xkcd]]'s website.
  
{{w|Direct current}} is a unidirectional flow of electrons from a power source to something being powered, through one or more conductors, before returning to the power source via one or more other conductors, thus completing the circuit. Batteries produce direct current.  It is commonly used in electronics applications, including computers. {{w|Alternating current}}, on the other hand, frequently reverses the direction of electron flow, and is commonly used for longer-distance transmission (such as from the power plant to an outlet).
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In electronics, {{w|direct current}} is a unidirectional flow of electrons from a power source to something being powered, through one or more conductors, before returning via one or more other conductors, thus completing the circuit. It is commonly used for battery-powered appliances. {{w|Alternating current}}, on the other hand, frequently reverses the flow of electrons, and is commonly used for longer-distance use (such as from the power plant to an outlet).
  
This comic proposes a humorous ''Meta-Alternating Current'', which uses a series of adapters to "alternate" between DC and AC current along the length of a connector. This is absurd in part because typical {{w|power inverter}} efficiency is 90%, and maximum {{w|bridge rectifier}} efficiency is about 99% for 120 V,{{actual citation needed}} so an {{w|extension cord}} made in this manner would lose about 11% power (compounded<!-- ...need a better word for this, but it's very much related to compound interest. It wouldn't be 100% loss after nine steps, but ~91% loss, i.e. 0.90*0.99)^9 -->) per such pair. For the wire shown in the comic, with seven pairs, the efficiency would be 0.89<sup>7</sup>, which is 0.45, that is, 45%.
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This comic proposes a humorous interspersion, ''Meta-Alternating Current'', which uses a series of adapters to "alternate" between DC and AC current. This is funny because since typical {{w|power inverter}} efficiency is 90%, and maximum {{w|bridge rectifier}} efficiency is 81.2%, an {{w|extension cord}} made of them would lose about 27% power per such pair. The "extension cord" shown would yield about 11% of its input power.
  
The title text bemoans that an inverter, which converts direct current to alternating current, does not work in the other direction, as a layman's interpretation of the word "inverter" might assume. Rather, a separate device, a {{w|rectifier}}, also pictured in the comic, must be used for this second conversion. (However, a similar circuit to an inverter may be used to rectify in a process called {{w|active rectification}}.)
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The title text bemoans that an inverter, which converts direct current to alternating current, does not work in the other direction, as a layman's interpretation of the word "inverter" might appear. Rather, a separate device, a {{w|rectifier}}, also pictured in the comic, must be used for this second conversion.
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Common understanding of "inverting" would be to turn upside-down, or reverse the input polarity in the output, something that would be easily done at near-zero inefficiency by just 'crossing' (without connecting between) the wires coupling the inputs and outputs. Two such cross-overs would indeed restore the original electrical supply. In the conversion from DC to AC it is instead an active circuit that ''periodically'' inverts, and then uninverts, the effective polarity – with a specific frequency, and usually a voltage conversion, to conform to some AC need such as using a car battery to power a standard household device designed and built for use on a mains supply. A rectifier is a nominally passive circuit that accepts either polarity (e.g. at any given moment of an AC phase) and produces a single definite polarity as output, possibly smoothed out by a buffering capacitance or with additional components to attain a given voltage and amperage.
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It may in fact be the case that a campsite use of a rectifying device intended for home use (e.g. a standard phone charger that down-converts household AC to a given DC) requires it to be plugged into an inverter itself powered from a battery system (DC to AC), more inefficiently than a single converter (with the correct voltage/amperage re-regulation) might accomplish the task. Further chaining this into more inverters/rectifiers would normally not be considered.
  
 
==Transcript==
 
==Transcript==
:[Above the drawing there is a header. Below the header is a chain of rectifiers and inverters. There are seven pairs of rectifiers (the smaller ones) and inverters (the big chunky ones). The first five inverters have arrows pointing to them from a label above the chain, whereas the last five rectifiers are labeled below the chain, but also with arrows pointing to them from that label. The chain starts on the left with a mains plug (type B), followed by the first rectifier. It ends with the last inverter, and a female mains plug (type B socket) to the right. Beneath the chain there is label for the connector and an explanation in brackets below that.]
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{{incomplete transcript|Do NOT delete this tag too soon.}}
:Cursed Connectors #120
 
:Inverters
 
:Rectifiers
 
:Meta-alternating current extension cord
 
:(alternates between AC and DC)
 
  
==Trivia==
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Cursed connectors #120
*This comic replaced [[No One Was Hurt]] as comic 2642 after it was taken down from [[xkcd]]'s website.
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**See why on that comic's explanation.
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Drawing of a chain of rectifiers and inverters.
*This comic initially did not have a high-resolution (2x) image for high-DPI displays, making it look more blurry than usual on such devices (such as smartphones). This was probably because it was uploaded hastily to replace No One Was Hurt quickly. It has since been updated to include a high-resolution version.
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There are seven pairs of rectifier/inverter.
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The chain starts on the left by a mains plug (type B), followed by the first rectifier. It ends with the last inverter, and a female mains plug (type B socket).
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Meta-alternating current extension cord
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(alternates between AC and DC)
  
 
{{comic discussion}}
 
{{comic discussion}}
 
 
[[Category:Cursed Connectors]]
 
[[Category:Cursed Connectors]]

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