Week -2

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

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In the above arrangement, when the switch is closed the electromagnet receives electrical power from the battery and pulls the metal arm to hit the bell producing sound.

Create a situation where the switch is closed for 2 seconds and then released. Observe the physical movement of the plunger.

BLOCKS used to build this mathematical model is

1. solenoid
2. battery
3. switch
4. scope
5. pulse generator
6. electrical reference
7. translational reference
8. motion sensor
9. ps- converter
10. Simulink- ps converter
11. solver configarations

Solenoid:

solenoid block has both mechanical and electrical characteristics, with that we can change the parameters as we required.

Battery:

battery is to supply the power to solenoid so that the plunger hitts the bell to make sound for two seconds.

Motion sensor:

to track the movement of the plunger we use the motion sensor.

Pulse Generator:

is used to generate the pulse according to given conditions. for above conditions the bell has to ring for the two seconds and off for the next two seconds.

the below shown image is the parameters set according to the above explanation.

the above shown image is the frequency of the sound waves generated for the two seconds and off for the next two seconds.

the above shown image is the pulses generate according to the given conditions.

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

Conditions:

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

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Electrical physical(Simscape) Blocks used for this simulink model are:

1. Thermistor
2. Resister
3. voltage sensor
4. electrical reference
5. Battery

Thermal physical (Simscape)blocks:

1. thermal reference
2. controlled temperature source

Simulink Blocks:

1. signal builder
2. constant
3. display
4. ps-converter
5. treshold switch
6. scope

the above blocks are used to make this mathematical model for the simulation.

Thermistor: the main function of the thermistor is to take thermal(temperature) as an input and gives voltage as an output. for the given conditions thermistor is make us to analyze the temperature and helps in switch on/off the fan.

treshould switch:

treshould switch is used to judge when the current as to allow through it to the dc motor.

Voltage sensor:

voltage sensor is used to sense the voltage and maintain the voltage.

Signal builder:

signal builder is used to adjust the parameters like temperature with respect to time. the parameters time and temperature(kelvin) is given according to the conditions mention in the question.

Conclusion:

The simulstion of mathematical models are done by using the SIMULINK.