Week -2

Aim:

1. Make simulation model of doorbell using solenoid block
2. Use thermister block to sence the temprature of heater to turn on /off ffan for given temprature conditions

Objectives:

1. Make simulation model of doorbell using solenoid block

• Understand working of doorbell
• genrate simscape model for boorbell
• simulate model for given situation i.e Switch is closed for 2 seconds and then released and obseerve the resultant plots

2.Use thermister block to sence the temprature of heater to turn on /off ffan for given temprature conditions

• Create temprature source, use thermistor for sencing temprature
• simulate model for given conditions i.e (Temp source=20 deg.C for 0 to 10 sec, 27deg.C for 10 to30 sec,23deg.C for 30 to 50 sec : Fan condition :ON if temp>25 else OFF

Part 1.Make simulation model of doorbell using solenoid block

Solenoid:A solenoid is an electromagnet where the coiled wire surrounds a metal piston(clapper) ,the piston is made of magnetic material so tht it can move forward or backword by the electromagnetic field.

• Working:

• As shown in animation above as switch pressed it activates electromagnet as current passes through it from battery .
• As electromagnet activates it atracts magenet wich is connected to clapper lever , on one end of clapper there is piston which strikes on "bell" which create sound
• Every time clapper strike on bell contactor get diconnected so circuit breaks and leaver come backward ,This process reoets unti switch is pressed

Input parameters for pulse genrator & Input pulse scope

Input pulse:

Simscape model:

Results:

Part2 Use thermister block to sence the temprature odf heater to turn on /off fan for given temprature conditions

Theory:

Tosove given problem we have to build model to turn on or off the fan asper given temprature values

Simscape blocks used:

Signal builder:

Ideal temprature source:Gives temprature values to system asper input signal

Thermistor: Is defined as a type of resistor whose electrical resistance varies with changes in temprature .Although all resistors resistance will fluctuate slightly with temprature ,a thermistor is particularly sesitive to temprature changes.

Voltage sensor:Gives voltage value i circuit.

Switch:If input 2 satisfies pass through input 1 ;Else pass through input 3 .This block fuction like if Else condition.

Simulink model:

Input parameter:

create input signal asper given temprature condition in signal builder

After running simulation we get threshold value for Switch which we inter in Switch parameter bliock

Result:

Output signal:

Fan will be on for 10 to 30 seconds .