Week -2
Aim:
1) To make simulink of a doorbell model using solenoid block.
2) To make a simulink to use a thermistor to sence the temperature of a heater & turn on or off the fan as per the given condition.
1) Simulink of a doorbell model:
To create the signal input a pulse generator is used to give the input values as per the asked time, that is the bell should ring for 2 seconds for every 4 seconds. So the pulse generator will give the signal for 2 seconds in every 4 seconds.
The options and the values given in the pulse generator is shown below.
The scope 1 is used to check wether the input signal is given correct. The signal should be 1 for the 1st 2 seconds and 0 for the next 2seconds.
As the pulse generator is a simulink value andthe bell switch is a physical connection, a simulink to ps converter is used to connect the signal with the input.
A battery is used to pass the electric current as it work in electricity.
Then the signal is send to the solenoid, which has the damping coefficient of 3 with 500 as the daping contact and 5mm as the spring force.
An ideal translation sensor is used to sence the motion of the bell(solenoid), then it is fed to the simulink using ps to simulink converter and the output wave is shown in the scope.
2) Simulink model to use thermistor to sence the temperature of a heater & turn on or off the fan:
The condition for the thermistor is:
Temperature source: 20 °C from 0 to 10 seconds, 27 °C from 10 to 30 seconds, 23 °C from 30 to 50 seconds.
Fan conditions: ON if the temperature above 25 °C, OFF otherwise.
The simulink model is made for the thermistor to sence and turn on or off the fan.
All the temperature values are converted from degree celcius to kelvin, and the kelvin values are given as the input as temperature.
The input signal in the signal builder is given as shown in below:
The signal input is feded to the temperature controller which works as per the input.
Then the output value from the temperature controller is connected to the termistor, and passes to the resistance.
Where the voltage is set in parallel to the resistor. To sence the voltage. 
This is used to check the voltage for the value of 25 degree celcius, as the fan should on when the temperature goes above 25 degree celcius.
Which will be then given as the threshold input for the switch for the fan to on or off.
Then a scope is used to see the plot of the fan whether it works correctly.
The fan should be on, that is it should be 1 for the time length of 10 to 30 alone.
Where the rest of the time it should be 0(off).
