Week -2

AIM : 1) To Simulink model of Doorbell using solenoid block.

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

SOL1:

1) To provide signal source pulse generator is used and as we have to close the switch for 2sec , period is choosen to be 4 sec and width as to be 50%of period , due to this the pulse will be high for 2 sec to make it more appropriate initial phase delay is kept as 2 sec, scope is added immediately after it so to know its behaviour.

2) As the output of the pulse generator is in simulink and the switch is physical we use SIMULINK TO PS converter and is connected to one terminal of switch .

3)To provide power battery is used and one terminal is connected to switch and other to soleniod, the other free terminal is connected to free terminal of soleniod.Now all these are grounded using Electrical Reference.

3)As we have to sense the motion of plunger in solenoid we use IDEAL TRANSLATIONAL MOTION SENSOR.

4)The output of sensor is to be converted to simulink to get the output in DISPLAY block PS TO SIMULINK converter is used,and output is displayed in display block ,to study the behaviour of plunger scope is used after ps to simulink converter

5)All the circuit is grounded using mechanical reference ,at the end we need to add a solver to our circuit which is added.

JUSTIFICATION: It is seen that after 2 sec when the pulse is raised to high amplitude that is when swutch is closed for 2 sec the plunger strickes for 2 sec after 2 sec when the switch is open the plunger returns back to its initial position.

SOL2:

1)To produce required signals according to the inputs SIGNAL-BUILDER is used where time line is changed to 50 sec and then for every time part i.e0-10,10-30,30-50 temperatures in kelvin 293,300,296 are set repectively.

2)As this is block gives simulink output and we need in PS simulunk to ps converter is used.Now CONTROLLED TEM. SOURCE is used which takes input from signal builder and to set its initial condition THERMAL REFERENCE is attached to other terminal. The output of this is heat this all over this works as HEATER .

3)The heat or the temperature from heater is sensed by THERMISTOR as we know the resistance of thermistor changes according to the temperature change and there is no Resistance sensor as resistor is added with voltage sensor parallel to it to get the voltages .

4)Out put of this now converted uding PS-SIMULINKconverter now as SWITCH is used which will work as our fan , this switch takes input from PS_SIMULINK converter and works as IF ELSE condition SCOPE is added to output of switch to know the its behaviour.

5)At last electric circuit is grounded and a SOLVER is provided.

JUSTIFICATION:from scope attached at the end it is clear that from 10-30 sec as the temperature is 300K and as we had condition that above 298K the fan must turn on this is working properly aslo after 30sec as theb temperature is 296K the fan is turned off as the scope line returns to zero, thus our simulink program is correct.