6 CCL BLDC Fan Further Development
This application note presents a basic setup for core independent BLDC fan operation
that can act as a starting point for adding more advanced features and/or control. Some
examples could be:
- Temperature based fan speed control: This could be implemented by connecting a temperature sensor via the ADC and set the PWM duty cycle based on the measured value. The duty cycle could, for instance, be set from a predefined look-up table or by a control algorithm.
- Closed loop speed control: This could be implemented by estimating the fan speed from the Hall sensor signal switching rate and using the value as input to a control algorithm.
- Stall detection: This could be implemented by detecting lack of Hall sensor signal switching.
- Analog reference input: This could be implemented by connecting a potentiometer to an ADC input and use the output value as the set point for a speed or temperature controller, or to simply set the PWM duty cycle directly.
- Serial communication: By using the SPI module, remote monitoring and control can be added. This could be very useful if the fan is to be integrated in a larger system with some higher level control scheme.