Stopping the fans

[lizardking]

I use the fancontroller to control several Noctua NF-A20-PWM fans. I can control their RPM between 330-approx 880RPM, but I cant stop them completely.
In the web frontend the sliders per fan are changing the RPM, but the on/off switch doesnt turn the fans off, it only sets them to the min rpm.

Is there any way to configure the board (latest hardware), so it actually turns off the fan when it should be off?

[oscill8ory]

I'm having the same issue. I have a Thermaltake CT200 fan and I'm not able to stop it either.

https://thermaltake.com.au/products/ct200-pc-cooling-fan-single-fan-pack-cl-f177-pl20bl-a

I notice the fan specs only range from around 500 to 900 rpm though, so perhaps I've messed up and bought a fan that can't go to zero speed via PWM control. I'd be happy if I could at least turn it off though, and when it's turned on, only be able to control speeds between min and max RPM.

[lizardking]

In the meantime I've learnt that my Noctua fans will not stop if PWM duty cycle goes to 0% and that the only solution to really stop them would be to cut the 12v power supply.
It seems that I need to design something myself, that can cut off the power if needed, unless a board revision with such possibilities is planned.
Are there any plans for this?

[Pel1can111]

No idea if this might be a fan specific issue but I have 4 x 140mm Noctua NF-A14 Industrial PPC PWM 3000RPM fans and they can be fully spun down if needed.

[patschi]

Same here. I am using 2x Noctua NF-A12x25 120mm PWM chromax.black.swap and they are able to fully stop.

[lizardking]

The different Noctua fans seem to have different behavior for 0% PWM. For my fans they state:

• Rotational speed @ 0% PWM | 350 rpm

[oscill8ory]

The different Noctua fans seem to have different behavior for 0% PWM. For my fans they state:

• Rotational speed @ 0% PWM | 350 rpm

@lizardking I'm glad you told me that, because one of my next options was going to be to try one of those fans instead.

I wonder if this is a standard "feature" of 200mm fans (i.e., not stopping at 0% PWM)