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12V Fan pin header FAQ
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d

daboone72

04/23/2023, 8:26 AM
Just for some reference info on the 12V connector
So on a 4 PIN black is ground and is closest to the key1 button.
And a useful all the connectors reference if you need to figure out others 3 pin etc. https://faqs.noctua.at/support/solutions/articles/101000081757-what-pin-configuration-do-noctua-fans-use-
c

colinriddell

04/23/2023, 11:07 AM
just connected my noctura fan with the noise limiter. Works good, but I seem to hear it slightly pulse.. even though it's not a PWM fan and the header isn't pwm either. Any ideas?
u

_dhanos_

04/23/2023, 1:28 PM
This is how you connect any 3- or -pin fan to TPi2:
This is odd. If you have a multimeter you might try to measure the voltage and see if it also pulses (both before and after the noise limiter)
c

colinriddell

04/23/2023, 4:36 PM
I think this might be because I stuck two limiters before the fan. I like how quiet it is, but unsure if it's a good idea?
u

_dhanos_

04/23/2023, 5:07 PM
The fan can potentially struggle a bit if you lower it the voltage too much. This is only a guess, though, I haven't noticed anything like this, but I also haven't stacked the "low noise" cables
h

Hizzie

04/23/2023, 7:38 PM
Another possible: Amazon FBHDZVV 4 PCS SATA Power Splitter Y Cable 1 to 1 15 Pin Male SATA to Sleeved 3 Pin/4 Pin PMW 12V PC
(Power Only)
c

colinriddell

04/23/2023, 10:13 PM
Is there any way to stop the power to the 12v header once node 1 has been powered off ?
this was almost certainly the issue btw.
u

_dhanos_

04/23/2023, 10:16 PM
There is - if you turn off all of the nodes using
key1
or power button in the case (if you are using any). There's a bug with other ways to control the power (like web interface) that will not turn off the PSU with the last node turned off. We'll fix it soon with the CE firmware
c

colinriddell

04/23/2023, 10:17 PM
Thank you
u

_dhanos_

04/23/2023, 10:18 PM
Interesting
c

colinriddell

04/23/2023, 10:24 PM
Yeah found out noctura recommend only one limiter per fan Doubling them up works but is a bit dodgy
u

_dhanos_

04/23/2023, 10:28 PM
Good to know, thank you
c

cbceebee

04/27/2023, 7:32 PM
Just to clarify: the 12v fan 2 pin header is just a fixed DC supply (no PWM or voltage variation on the 12v pin)?
u

_dhanos_

04/27/2023, 8:27 PM
The fan header can have 2-4 pins: 1. ground 2. +12 V 3. RPM/taho (this was the controller knows fan speed) 4. PWM (this way the controller controls fan speed) So: 2-pin header: only has power pins 3-pin header: has power pins and can report own speed 4-pin header has power pins, can report own speed, can be controlled There is also an old standard where you could control fan speed by the voltage on the power pins, but this is not used in the TPi2
c

cbceebee

04/27/2023, 8:28 PM
thanks for clearing things up
r

rbenj406

05/21/2023, 5:37 PM
Can the 12v FAN header be used to power an external PWM controller for fans on multiple CM4? How much power can this header supply? I have 2 CM4 so far, and intend to use these heatsink/fan combo. https://www.amazon.com/dp/B0B4HCL62K?_encoding=UTF8&psc=1&ref_=cm_sw_r_cp_ud_dp_7RFVWGZXD5HFN44XWWBE
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_dhanos_

05/21/2023, 7:03 PM
Yes it can. It can supply up to 2A
d

dadcoachengineer

05/22/2023, 11:11 AM
Any update on the 4 pin fan pads with no pins soldered?
u

_dhanos_

05/22/2023, 4:26 PM
What update do you mean? This one is not populated and is not working.
d

dadcoachengineer

05/22/2023, 4:40 PM
Got it. I though I read somewhere that it may be enabled in soft/firmware at some point to support a case PWM fan.
u

_dhanos_

05/22/2023, 4:41 PM
It cannot since there's more unpopulated parts than just the connector.
d

dadcoachengineer

05/22/2023, 4:42 PM
Got it. Thank you for the clarification 🙏🏻
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