Week -2

AIM:

To make a simulink model of a doorbell using solenoid block.

To use a themistor to sense the temperature of a heater & turn on or turn off the fan.

1.DoorBell;

Using Solenoid:

The solenoid is a eletromagnet. On passing current throught the conducting wires a magnetic field is generated around it which attacts magnetic materials. This phenomenon is used in the bell when the switch of the bell is pressed the current passes throught the circuit exciting the eletromagnet and pulling the plunger toward the metal portion. This product a ringing sound.

Simulink Model Explanation:

* The pulse generator is used to create square wave pulses at regular interval.. The block wavefrom parameters amplitiude pulse width period and phase delay determaine wavefrom.

* The switch block used is controller by external physical signal. If the external signal is greater than the thersold parameter then the switch is closed otherwise switch is open.

* The positive terminal of the of the switch is connected to switch and the negative is connected to the electrical reference.

* The solenoid block is connected with switch and battery and we will grt a completer eletrical circuit. The port c is connected with with mechinical reference.

* The idea translation sensor is connected with solenoid block R to obsereve the movement of the plunger.

* Scope is connector with the ideal translation sensor to get the output.

* PS –Simulink converter is used to convert the physical signal to simulink signal.

* Solver configuration :Each phsical network represented by a connected simscape block requires solver setting information for simulation.

(1).The image shows the pulse pattern give as input . The cycle repeats for 20 second.

(2).As we want the circuit to be closed only in the interval of 2 second a switch block is used . The switch block has a therhold value of 0.8 . Threshold of the pluse generatoris 1 . The switch will only close if the value of thershold more than 0.8. This the connector to solenoid block which contain the plunger arrangement. Initially when the plunger is away from c the value of x is 5mm and when the plunger is near c the value of x is 0mm.

Results:

2. Thermistor ;

Given inputs :

Temperature source 20°c from 0 to 10 second , 27°c from 10 to 30 second , 23°c from 30 to 50 second.

Fan conditional ON if the temperature about 25°c OFF otherwise.

Simulink model:

SIMULINK MODEL EXPLANATION;

Signal builder block is used to input the values as per given conditional.

At point 1,Time=0 second , temperature=293k

At point 2, Time=10 second ,temperatuire= 293k

At point 3,Time =10 second, temperature=300k

At point 4, Time=30 second, temperature=300k

At point 5,Time=30 second,temperature=296k

At point 6, Timer=50 second, temperature=296k

* Controlled temperature source represents an ideal source ofvthermal energy that can maintain a controller temperature difference regardless of the heat flow rate . The temperature difference is set up by the physical signal port S . A positive temperature difference causes the temperature are port B to be greater than temperature at port A.

* Thermistor is a type resistor whose resistance eis based upon temperature.

* A linerar resistor is used inored to control the amount of current from the battery.

* The voltage sensor is used to convert the voltage measured brtween two point into a physical signal.

* Voltage source which represers DC or AC

SOLVER CONFIGURATION;

Each physical network represented by a connected simcape block requires solver setting informatuion for simulation.

The time period given is 2 second to the pulse generator to open and close the as switch. When the switch is closed the solenoid block receives electrical power from the batter and the plunger mover from port R to C to hit bell and produce sound .

Result:

For 0 to 10s fan is OFF condition because temperature is 293k which is below the thresold 298k. After 10s temperat ure goes to 300k then the switch will be in ON condition as the temperature exceeds 298kk. After 30s fan will turn OFF as the temperature comes down to 296k which is below the thresold temperature of 298k.