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633 Service Fan control change

Heffo

New member
Hi,

I am using my 633 and the 633 service to regulate the fan speeds in my case & watercooler based on the temperatures of the water in the system

My system fans wont spin up until about 20% pwm, and will stall once spun up at around 10% pwm, I was wondering if it would be possible to modify the service so that there is a complete shutdown threshold so that say below a set temperature a certain fan is completely stopped, then once above that it jumps straight to the existing lowspeed setting?

In my case, this is so that below 30deg C, the radiator fans are completely off and the air from the intake fans which can only escape through the PSU and the radiator is keeping the system cool & quiet, and when the system load forces the water above 30deg C the fan will kick straight in at 25% pwm then linearly ramp up to 100% pwm at around 75-80deg C

I will also post some pics of my nicely modded Lian Li PC75 once I get a chance to take some
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CF Mark

Administrator
I thought about this when i was first writing the fan control code, but wasnt quite sure how to fix this possible problem.

Now youve brought it up, ill think about it some more.

How about a setting like "fan_start_speed" which would be a percentage?
Any speed below this setting would result in 0% PWM, everything above, would be the normal % PWM.
 

Heffo

New member
Hi,

the fan_start_speed setting would be a great addition to avoid burning out fans when feeding them an extremely low pwm, but I also think adding low_temp_cutoff which takes a temperature, that also sets a 0% pwm at or below the cutoff temperature, so that the loudest fans dont even start until the temperature reaches a set level
 
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CF Mark

Administrator
Heffo said:
... but I also think adding low_temp_cutoff which takes a temperature, that also sets a 0% pwm at or below the cutoff temperature, so that the loudest fans dont even start until the temperature reaches a set level
But that wouldnt be needed if you had "fan_start_speed".

You say your fans spin up at 20% and stop at 10%.... so you would set "fan_start_speed" to 20%.

BTW, i doubt youll ever burn out a fan from a low PWM setting.
 

Gooserider

New member
CrystalControl Admin :
quote: Originally posted by Heffo ... but I also think adding low_temp_cutoff which takes a temperature, that also sets a 0% pwm at or below the cutoff temperature, so that the loudest fans dont even start until the temperature reaches a set level

But that wouldnt be needed if you had "fan_start_speed". You say your fans spin up at 20% and stop at 10%.... so you would set "fan_start_speed" to 20%. BTW, i doubt youll ever burn out a fan from a low PWM setting.
I think a fan cutoff temp setting (both PWM% and temp) is needed as well. Without it how would the software know when to put the PWM to zero? I don't feel comfortable with just waiting for the fan to stall, and would like to have the fan go off completely when not needed (after all there is no fan as silent as one that isn't running :D ) Having fans stall might also cause problems with any fan speed alarms, but the alarm shouldn't trigger if the fan is supposed to be off.

Also I see it as a means of preventing the fans from exhibiting a 'hysterisis' problem of cutting on and off as the temps hover near the turn on point.

As an example, have a 'fan_start_temp' of 30*C and 'fan_start_speed' of 25% PWM, ramping to 100% PWM as temps increase to 70*C. As temps come back down though, the PWM might ramp down on the same curve (thus going to a lower % PWM than the 'fan_start_speed' ) but have a 'fan_stop_temp' of say 25*C when the PWM would go to 0%. Obviously the actual values should be user settable, with the obvious provision that 'fan_start_temp' must be higher than 'fan_stop_temp'.

Having both functions IMHO is needed so that the desired 'knee' in the temp / pwm curve happens in both directions, but at different times.

Gooserider
 

Heffo

New member
OK, it's getting towards the time of the year when the room temperature is slowly heading towards the 0deg C mark! and I really would like to be able to completely shut my fans down at 15deg C and below, since I don't want to risk even the remotest possibility of condensation buildup on my watercooler.

I was wondering if you had thought of, or added the low temperature cutoff for fans into CC1 yet?

It's starting to worry me a little!
 
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