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It is a forces air-conditioning driver for home use. The system was developed on evaluation board EvB. The main element of the circuit is Atmega16. LCD 4x20 characters shows the time, temperatures inside and outside the house, as well as currently selected operating mode.
The driver is designed to enable and disable the PC fans (80mm) that are placed in the ventilation grilles. Air is pulled out of the kitchen, two bedrooms and a bathroom. Sometimes there is moisture in the house, unfortunately, there is no air circulation. Presented here device is an useful solution in such a situation. Fan speed is controlled by PWM of a resolution of 10%. Type of work can be chosen from the menu. The temperature is read by two DS18B20.
- automatic, according to the temperature: set the temperature threshold, at which the fans will be enabled for sure. After decreasing temperature by 0,2 degrees Celsius, fans rotate for 30% turns.
- automatic according to the time: set the fans speed for active time. Additionally, you can set two times: operation and break time. During the operation, fans rotate with the set speed, during the break they are set to 30%. Maximum time of work/break is 60 minutes. Set by 5 minutes.
- manual mode: set only the speed with which the fans are to rotate. Continuous work.
The circuit is powered from toroid transformer 30W. Transformer with two voltages was created: after rectifying 8V DC for uC stabilizer and 16V DC for fans.
Pictures of construction:
Link to original thread (useful attachment) - Sterownik domowej wentylacji ATmega16