Total silence is but a dream, these things run super hot!Well most refrigerators aren't that quiet either
I don't know whether this will work but you could try to connect your pulse generator output to the PWM input of you fan. Assuming your pulse generator is generating a square wave with 50% duty cycle. your fan should spin at the speed close to the midpoint between the maximum speed and the minimum speed of you fan profile.ok so I'm at my technical limits here guys so if anyone can help please reach out:
i got the pulse generator modules from Amazon and tested them on my pc and they work fine, they are outputting ~8,000RPM based on the pot setting.
i also took the power supply apart. the pinout for the fan connector seems pretty basic:
1.red - LED power
2.green - LED GND
3.yellow - FAN RPM sensor
4.brown - FAN PWM control
5.black - FAN GND
6.orange-FAN PWR
these are the tech specs of the fan i was able to find online (9GV0412J301):
https://www.mouser.com/datasheet/2/471/San_Ace_40GV28_E-1286218.pdf
https://www.sanyodenki.com/archive/document/product/cooling/DC_PWMcon_en.pdf
it looks like the fan "could" run at lower RPMs by sending a lower PWM control signal.
could i do this just by soldering a resistor in between the connections?
thanks all.
So are you saying by doing this I would show the power supply a fan RPM speed of 8,000 rpm but have the fan running at 4,000 RPM?I don't know whether this will work but you could try to connect your pulse generator output to the PWM input of you fan. Assuming your pulse generator is generating a square wave with 50% duty cycle. your fan should spin at the speed close to the midpoint between the maximum speed and the minimum speed of you fan profile.
rpm = (max_rpm - min_rpm) * duty_cycle + min_rpmSo are you saying by doing this I would show the power supply a fan RPM speed of 8,000 rpm but have the fan running at 4,000 RPM?
Hi,
I doubt that it would work (could be wrong). The PWM signal to the fan is sent at a frequency of 25kHz and have a voltage between 0-5V, and from what I can see of a typical RPM signal it is pulled low two times per revolution (8000 RPM = 16000 pull low/min = 267 / second), which is far from sufficient to generate the required PWM signal.
An alternative for generating the PWM signal is to set up an Arduino to do it: Set PWM frequency to 25 kHz
Easiest and probably cheapest way would be to get one of these: https://www.amazon.com/Noctua-NA-FC1-4-pin-PWM-Controller/dp/B072M2HKSN.
Alternative: https://www.amazon.com/Wire-PWM-Cas...ntroller&qid=1561112914&s=electronics&sr=1-18
edit: Alternatively, you could replace all of the fans with ones that run a bit quiter, but that will cost a wee bit.