Week -2

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

Theory : - 1. Electro magnetic induction principle is very versitle to understand the concept of with out primary and secondary connection how we can transfer electric energy like in transformer.

2. Same here the solenoid is working with the same principle, for energising the magnet we can store the electro magnetic energy in form of the magnetic field in inductor.

3. here instead of AC , dc is very comfortable and portable , here battery used for generating the voltage and current , and due to the pressure of the voltage , flow of electrons are flowing through switch and switch is turn on , it enables flow of electrons in solenoid, and by using electro magnetic induction principle the end of the solenoid connects to plunger and plunger can make force , and that plunger connection we can connect to any metal bell, once the switch is turn on the plunger force can make a sense to the metal then it will buzz.

Component name	library	Parameters
Battery	Simscape/electrical/sources	12V
Electrical reference	Electrical elements
Switch	Electrical Elements
Pulse generator	Simulink/sources
Ideal translation motions sensor	Simscape/electro mechanical/mechatronics actuatros
solenoid	Simscape/electro mechanical/mechatronics actuatros
solver configuration	utilities
Mechanical translation reference	Mechanica translation elements

Results: Results are attached . Damping force variations also shown in scope.

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

Theory :- thermistors are for measuring the temperatures, example the PC fan is on, when the PC temperature is too high.

resistance is changes with temperature means increasing called positive temperature cooefficient, if resistance is decreasing temperature is increasing called negative temperature coefficient .

Temperature sensor is using for sensing the temperature,

Working:- if thermistor resistance is good at room temperature means , current will not flow to the fan, if thermistor is getting too much heat means thermistor resisance is decreasing and current flowing is increasing in fan then fan will rotate,

conclusion : between the power supply and PC of fan we can indulge thermistor for checking temperature, according to the temperature of thermistor fan automatically turn on and turn off . here for rotating fan we used small DC motor, which one working by PWM means from H Bridge we can get PWM pulses if pulses are too much motor rpm will increase, so from thermistor only flow of electrons can control which one coming from power supply.

Model is , power supply , thermistor, fan , dc motor, PWM bridge, temperature sensor in scope we can see temperature, heat, resistance, speed of dc motor variations by using thermistor.