Technical info
PWM (Pulse width modulated
fan control) is the better option
PWM is a simple and efficient method to control the speed of a fan. The fan maintains its nominal voltage and its speed is not reduced by lowering the voltage as a separate control signal determines the desired speed.
Noise reduction, efficiency, enhanced start-up behaviour
The most important advantages are noise reduction and efficiency. As the control system dissipates non-linear power, fewer power losses and less additional heat are generated in the system. This is a distinct advantage for compact devices or multiple fans.
PWM also enhances the start-up behaviour. Due to the fact that the fan operates at full supply voltage, it starts up more reliably than with a highly reduced operating voltage. This reduces problems that are caused due to tolerances, ageing or tight bearings.
Easy to integrate
For designers PWM is easy to integrate as micro controllers, fan controllers or embedded systems can easily generate the signal. The actual speed can be monitored with a tacho signal and integrated into a closed loop.
Thanks to the PWM control, the fan can be regulated as needed and runs only as fast as required which has the advantage that the fan is not louder than necessary.
A brief summary of the benefits
- Efficient
- Easy to regulate
- Improved start-up behaviour
- Easy to integrate
- Noise reduction
