garostoss
Newbie level 5
Microcontroller based PWM fan controller with temperature feedback and overvoltage protection
The developed device should control the speed of a low voltage DC fan using a programmable microcontroller. The controller should cut-off the supply to the fan if the supply voltage exceeds 14V It must also automatically run the fan at full speed if the temperature in the ventilated area exceeds 70 deg C.The minimum specifications are:
1. The device should provide manual speed control of a 12V DC fan using pulse width modulation.
2. The control should be exercised either by the means of a potentiometer or by two push-buttons for acceleration and deceleration of the fan’s motor.
3. The device should be able to supply to the fan a current of up to 3A.The nominal voltage of the motor is 12V DC.
4. The speed of the motor should be controlled continuously from zero to its maximum value, corresponding to 12 V DC supply.
5. The fan motor supply should be disconnected if the supply voltage to the controller exceeds 14 V. It should be re-connected automatically if it is below 14 V.
6. There should be a red LED light on the front panel of the device indicating the ‘overvoltage’ condition described in 5.
7. The device should have an externally connected temperature sensor that should monitor the temperature of the ventilated by the fan area. If the temperature on the sensor exceeds 70 degrees C, the controller should start operating the fan automatically at maximum speed, regardless of the current manual setting. The speed of the fan is restored to the relevant manual setting once the temperature drops to 60 deg C.
8. The ‘high temperature’ condition should be indicated by a dedicated LED light on the front panel of the device.
i am struggling with this please assist.
The developed device should control the speed of a low voltage DC fan using a programmable microcontroller. The controller should cut-off the supply to the fan if the supply voltage exceeds 14V It must also automatically run the fan at full speed if the temperature in the ventilated area exceeds 70 deg C.The minimum specifications are:
1. The device should provide manual speed control of a 12V DC fan using pulse width modulation.
2. The control should be exercised either by the means of a potentiometer or by two push-buttons for acceleration and deceleration of the fan’s motor.
3. The device should be able to supply to the fan a current of up to 3A.The nominal voltage of the motor is 12V DC.
4. The speed of the motor should be controlled continuously from zero to its maximum value, corresponding to 12 V DC supply.
5. The fan motor supply should be disconnected if the supply voltage to the controller exceeds 14 V. It should be re-connected automatically if it is below 14 V.
6. There should be a red LED light on the front panel of the device indicating the ‘overvoltage’ condition described in 5.
7. The device should have an externally connected temperature sensor that should monitor the temperature of the ventilated by the fan area. If the temperature on the sensor exceeds 70 degrees C, the controller should start operating the fan automatically at maximum speed, regardless of the current manual setting. The speed of the fan is restored to the relevant manual setting once the temperature drops to 60 deg C.
8. The ‘high temperature’ condition should be indicated by a dedicated LED light on the front panel of the device.
i am struggling with this please assist.