What is PWM fan speed control?
PWM stands for pulse width modulation. PWM fans and/or pumps are found in some CPU coolers and GPU (aka graphics card) coolers. They use an integrated circuit to control the speed of a fan or pump and, therefore, how much cooling it’s providing to the CPU or GPU.
How does PWM fan control work?
PWM, in brief, uses the relative width of pulses in a train of on-off pulses to adjust the level of power applied to the motor. A 2-wire fan is controlled by adjusting either the dc voltage or pulse width in low-frequency PWM.
Which is better PWM or DC?
PWM fans are useful because they minimize noise output and are more energy efficient than DC fans. Due to how they function, the bearings in a PWM fan will last much longer.
Is PWM quieter than DC?
With most 12V fans, the lowest voltage value is 6-7V before it stalls. As mentioned above, DC fans are typically 3-wire and have a power, ground, and tachometric or “tach” output. As you might expect, DC fans are typically louder than PWM fans as they spin at maximum RPM, regardless of perceived temperature.
What should the PWM frequency of a fan be?
If the fan has a PWM speed control input (typically this is a “4-wire” fan), the recommended PWM frequency is usually in the 20kHz to 30kHz range. PWM_OUT is a CMOS output that can be connected directly to most fans’ speed control input as shown in the 4-Wire Fan-Speed Controller Typical Application Circuits.
What are the PWM specifications for a Noctua fan?
As specified by Intel (c.f. “4-Wire Pulse Width Modulation (PWM) Controlled Fans”, Intel Corporation September 2005, revision 1.3), the square wave type PWM signal has to be supplied to the PWM input (pin 4) of the fan and must conform to the following specifications: Target frequency: 25kHz, acceptable range 21kHz to 28kHz
What can I do with the max31740 fan speed controller?
General Description The MAX31740 is a sophisticated, yet easy-to-use fan- speed controller. It monitors the temperature of an external NTC thermistor and generates a PWM signal that can be used to control the speed of a 2, 3, or 4-wire fan.
What is the Noctua PWM na-fc1 speed control?
For applications that only require manual rather than automatic speed control, Noctua’s NA-FC1 is a small, easy and straightforward way to control 5 and 12V PWM fans in non-PC environments.