PWM works by increasing the width of the pulses from 0 to 100%. That then translates to fan speed. I don't know whether the Voltage goingfrom the PCB to the fan changes or the signal to the motor changes. But the PWM signal to the PCB is 5 Volts. Steady 5v = 100%. Grounded PWM line = 0% duty, which means 0 RPM on Noctua and Enermax fans, alow but irreducable speed on some other fans, or full speed on yet other fans.
I cover the Phanteks "PWM Hub" in the above review. At 10% PWM duty the hub put out 3.5-4 Volts. At 100% around 11.5+ Volts. It's really an elegant way to control fans -- expecially since you can get a boost from the PSU.
Phanteks used to make a separate PWM-to-Voltage converter that you could get for free -- if you had bought their tandem tower heatsink and asked for the converter. I don't know about now, however.
New "PWM Hub" is PWM to variable voltage.
PH-TC14PE still has "PWM External Adaptor" listed on component list.
The "1x PWM External Adaptor" is 4pin in and 3pin out.. 3pin out hooks to 3pin Y-splitter to fans.
Look at the fans on new PH-TC14PE. They should have black rubber in mounting holes and are PH-F140HP fans.
So if PH-F140HP are 4-pin PWM why is the "1x PWM External Adapter" and the "2x 3-pin fan connection" for?
According to HiTech review of PH-F140HP
Here the PH-F140HP / TS is 3-pin
Here's an image of one of my PH-F140HP? on PH-TC14PE box showing "1x External P.W.M Adaptor" and "1x Y Fan Splitter"
Maybe the individually sold PH-F140HP is not the same PH-F140HP as included with PH-TC14PE?
Edited by doyll - 1/5/14 at 11:02am