Week -2

2) THERMISTOR MODEL -

Thermistor means a resistor whose resistance value depends upon the temperature . In model , the input is given through Repeating sequence stair which is connected to temperature controlled source which is further connected to thermal resistor which is known as thermistor . Thermal resistor has two inputs , one is for sensing temperature and other has two terminals positive and negative . These two terminals have been connected to dc voltage source . A resistance of R ohm has been provided with thermal resistor . Voltage sensor has been provided to caputre the voltage across the resistor and display it as output . Switch is connected to the output of voltage sensor with two constant blocks which will work as on-off state . The lamp is connected to the output of switch . 12V DC supply is given with the help of DC Voltage Source . When the temperature is above 298K the colour turns to Green and when temperature is below the colour turns to Red . Here below are meanings of some parameters , values of above parameters (T,V,R) can be changed through Comand window .

a) T - Temperature in kelvin having values [293 300 296] . Sample time is 10s .

b) V- Voltage in volts .

c) R - Resistance in ohms .

d) 1 - On state .

e) 0 - Off state .

The simulation time given when using repeating sequence pair is 50s and when using constant block of having value 298K is 10s .

1) DOORBELL MODEL -

The simscape model of doorbell has been attacted below .

Here due to the trial version of software i have to use substitute of solenoid that is translational electromechanical . DC supply of 12V is given with the help of DC voltage source. Here in the model the switch is close for 2 secs and open for 2 secs. In pulse generator the period is set at 4 and pulse width is set at 50% of period . The simulation time given is 8 secs . The blocks used in this model are ,

1) Pulse generator

2) Switch

3) DC Voltage source

4) Transaltional Electromechanical

5) Translational Motion Sensor

6) Scopes , one for pulse generator and second for observing position of the bell .

The input and output can be observe through scopes .