Week -2
- Make a Simulink model of Doorbell using solenoid block with the following details:
Ans: Solenoid model is used from electrical simscape with on/off provision. For switching solenoid on/off position, a trigger switch is made with the help of repeating sequence of 2 seconds.
Once switch is turned on for 2 seconds, solenoid gets energised to become magnet and pull the plunger of bell by electromagnetic force. Plunger gap becomes zero from its initial position of 5mm. As plunger hits the gong, it rings and whole process repeats with a frequency of 2 seconds.
Same process can be seen in simulink model attached for reference.
2. Use a thermistor to sense the temperature of a heater & turn on or turn off the fan as per the below conditions:
Ans: Heater block is created with temperature heat source of 20 °C from 0 to 10 seconds, 27 °C from 10 to 30 seconds, 23 °C from 30 to 50 seconds. Heater is connected to thermistor which is a NTC type.
As temperature increases resistance of thermistor decreases and voltage increases. At 25°C temperature voltage found to be 0.1157 volt. It indicates if thermistor voltage is more than thersold 0.1157 volt then it indicates temperature more than 25°C.
So now this voltage(0.1157 volt) becomes thresold for switching fan on or off as per reuirements fan needs to be on once temperature crossed 25°C.
A logic switch is created with on/off provision with the help of if else statement. As per per logic if thermistor voltage goes more than thersold 0.1157 volt then fan gets turned on.