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What does PWM fan control mean?
pulse width modulation
“PWM” stems from electrical engineering and is short for “pulse width modulation”, which is also known as “pulse-duration modulation”. What it means is that you can use it to almost freely control the RPM of a fan. The speed of regular fans can be modified by voltage regulation.
Can 3 pin fans be PWM?
With the 4-pin PWM to 3-pin transformer, all 3-pin fans can now be controlled with a normal PWM signal. The converter is connected to your motherboard or PWM fan control, while the fans are connected to the converter. Now your 3-pin fan can be controlled like any other PWM fan.
How does a PWM drive control a fan?
method a PWM drive signal is applied to a field-effect transistor (FET), which is connected to the high or low side of the fan. The fan will be on/of f at a particular frequency and the speed of the fan is controlled by the duty cycle of the PWM signal.
What’s the difference between PWM and high frequency fan?
With high- frequency PWM, the fan can be run at speeds as low as 10% of full speed, while the same fan may only run at a minimum of 50% of full speed using linear control. It is more energy efficient, because the fan is always either fully on or fully off.
Which is the best fan speed control method?
From the standpoints of acoustic noise, reliability, and power efficiency, the most preferable method of fan control is the use of high-frequency (>20 kHz) PWM drive. Besides eliminating the need for noisy pulse stretching and the commutation noise associated with low-frequency PWM, it has a much wider control range than linear control.
How is the speed of a 3 wire fan controlled?
This form of speed control is open-loop. A 3-wire fan can be controlled using the same kind of drive as for 2-wire fans—variable dc or low-frequency PWM. The difference between 2-wire fans and 3-wire fans is the availability of feedback from the fan for closed-loop speed control.