Week -2
Aim : 1.Make a Simulink model of Doorbell using solenoid block
2. Use a thermistor to sense the temperature of a heater & turn on or turn off the fan
1.Simulation Model For Doorbell
Model Explanation : Firstly block require for this model is pulse genrator, switch, battery, solenoid, ideal translational motion sensor, mechanical reference, elecctrical reference and scope. The Pulse genrator is used to create square wave pulse at regular interval. So as per condition the bell is engaged for 2 sec and then relesed for 2 sec. The time period as 4sec and Pulse width as 50% of 4 sec. After that signal from pulse genrator signal converted via simulink-ps converter and given to switch as a input. In series with solenoid battery is connected and also switch is connected. The solenoid R port connected to ideal translational motion sensor for observe the movement of the plunger. Both mechanical and electrical referance connected to the respective circuits. The output from ideal translational motion sensor is converted using ps-simulink converter & output will show in scope.
Result : From graph we can see that at each 2 sec interval the bell is ringing. 
2.Simulation Model For Thermistor
Model Explanation : Firstly for Temperature source conditions we required signal builder block. So we can adjust at paticular time at paricular temperature value. The temperature value will converted into kelvin for eg. 20 °C = 293K. This signal from signal builder in the form of simulink signal so it will required converter which is nothing but simulink-PS converter and applied to controlled temperature source block through thermistor. Resistor connected in series with thermistor to avoid negative load signal to switch. After that it will convert into PS-simulink converter and applied to switch. The switch having 3 input and 1 output. Th middel one is connected from PS-simulink converter and other two input for condition i.e. 1 = On and 0 = OFF. This switch required to set threshould value by comparing two signal which is first from signal builder input and other from voltage sensor signal. The threshould value is 0.012(298K) means Fan will be ON if the temperature above 25 °C(298K), OFF otherwise.
Result : Simulation run by 50sec and we will get following output.
