Week -2

1. Make a Simulink model of Doorbell using solenoid block with the following details:

In this simulink model, I have used pulse generator with amplitude 2 for a period of 4 secs and applied it to physical switch using simulink to ps converter. When the switch is turned on the solenoid recevies power supply from the battery and develops magnetic field around it which creates force on spring and spring moves. The motion of the spring is captured using ideal translational motion sensor.

From the scope we can observe that the spring motion can be only seen during switch ON time i.e. for 2 seconds and later time spring motion is zero.

2. Use a thermistor to sense the temperature of a heater & turn on or turn off the fan as per the below conditions:

In this simulink model, I have used signal builder in which I have defined the temparature according to the question. The thermistor is subjected to temparature using temparature controlled reference which gets input from signal builder. The thermistor changes it resistance value with change in temparature. A resistor is connected in series with the thermistor and battery and voltage fluctuations are captured using voltage sensor.

I used a simulink switch where it will check the voltage sensor value is greater than 1.579V or not. If yes then dc motor gets power supply and fan will rotate else no power is suppiled to motor and our condition will also satisfies. The output of the dc motor can be seen from the scope where the graph shows output only in the region of 10 to 30 secs of time.