PC Fans: Difference between revisions

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A junction must propagate only one tachometer signal, i.e. if three fans are connected to a splitter, only one tach value is reported. Whether this is a maximum, or an average, or something else is undefined, but every junction I've ever seen, from passive splitters to active controllers, simply connects only one tachometer to the wire (controllers using a side channel in addition to the fan connector might of course report multiple tach signals, as does the [https://shop.aquacomputer.de/product_info.php?products_id=3832&language=en Aquacomputer OCTO] via USB).
A junction must propagate only one tachometer signal, i.e. if three fans are connected to a splitter, only one tach value is reported. Whether this is a maximum, or an average, or something else is undefined, but every junction I've ever seen, from passive splitters to active controllers, simply connects only one tachometer to the wire (controllers using a side channel in addition to the fan connector might of course report multiple tach signals, as does the [https://shop.aquacomputer.de/product_info.php?products_id=3832&language=en Aquacomputer OCTO] via USB).


==Connector and wiring==
==Physical==
===Connector and wiring===
[[File:Pwm.jpeg|thumb|right|Pinout (GND, power, tach, PWM).]]
[[File:Pwm.jpeg|thumb|right|Pinout (GND, power, tach, PWM).]]
Intel specifies UL1430 wire with a minimum AWG26, 300V capacity, with rating of at least 105℃.
Intel specifies UL1430 wire with a minimum AWG26, 300V capacity, with rating of at least 105℃.
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Both connectors ought employ a polarizing rib between the third and fourth pin to ensure correct connection. The absence of such does not preclude mating with a ribbed connector; an offset connection is almost certain to blow the tachometer circuit [https://kampidh.blogspot.com/2021/02/even-deeper-into-rabbit-hole-4-pin-pwm.html if the device is externally powered].
Both connectors ought employ a polarizing rib between the third and fourth pin to ensure correct connection. The absence of such does not preclude mating with a ribbed connector; an offset connection is almost certain to blow the tachometer circuit [https://kampidh.blogspot.com/2021/02/even-deeper-into-rabbit-hole-4-pin-pwm.html if the device is externally powered].
===Form factor===
'''FIXME'''


==External links==
==External links==