Week -2

MAKE A SIMULINK MODEL OF dOORBELL USING SOLENOID BLOCK .

AIM:

1. to make simulink model for a doorbell using solenoid block .

SIMULINK MODEL EXPLANATION :

Used following blocks in the model.

1.battery

2.switch

3.pulse generator

4.solenoid

5.mechnical translational reference

6.ideal translational motor sensor

7.scope

8.electrical reference

switch block is controlled by external physical signal & if the external physical signal is greater than the switch is closed or else switch is open.

positive terminal is connected to blcok whilw as , the negative terminal is connected to the electrical reference.we connect solenoid block with the switch and battery the ideal translational sensor is connected with the solenoid block r to observe the movement of the plunger. the port c is connected with mechanical reference.scope is connected with ideal translational sensor to get the output.the signal from the pulse generator was converted using the simulink ps converter and given to the input switch

the voltage of the battery connected was made as same as that of the rated voltage of the solenoid.the switch is also connected to the same circuit.the position of the solenoid plunger is measured using an ideal translational motion sensor connected to the circuit.the initial position of this is set to 5mm in the translational motion sensor.the scope is connected to visualize its behaviour.the spring constant and damping parameters of the solenoid block was altered to obtain the desired graph.

the simulation was run for 30 sec. and the result obtained is shown above.it can be observed that at each 2 sec. bell was ringing.

CONCLUSION:

Giving input as time peroid for sec. in the oulse generator to open and close the switch.the switch is closed the solenoid block receives electrical power from the battery and plunger moves from port R to port C to hit the bell and produced sound .

THERMISTOR:

Aim:

To make a simulink model using a thermistor to sense the temperature of heater and turn on and off the fan as per the below condition :

THERMISTOR :

A thermistor is a type of resistor which has property of incresing its resistance linearly with respect to increasing temperature.

1.temperature source

a. 20 degree c from 0 to 10 sec. .

b. 27 degree c from 10 to 30 sec. .

c. 23 degree c from 30 to 50 sec. .

2. fan condition :

1. on if the tempareture is above 25 degree c , off otherwise.

THE BASIC COMPONENTS USED TO COOLING FAN CIRCUIT :

1.thermistor

2.battery

3.resistor

4.voltmeter

5.solver configuration

6.signal builder

7.electrical reference

8.control temperature source

9. 2 constant , scope , switch

the formula for conversion: 1 degree c = 273.15k

the signal 1 is

From 0-10 sec. temp. is 293.15k

From 10-30 sec. temp. is 300.15k

From 30-50 sec. temp. is 296.15k

EXPLAINATION :

A thermistor is used along with a resistor and a battery to create a circuit . the thermistor is connected to an control temperature source and a voltage sensor is provided across the resistor to measure the voltage difference.

the temperature source is provided with input signals as per the given conditions in question.the output from the voltage sensor is given to the switch.a dc motor is used which has its one end connected to switch output and other end to a rotational motion sensor.the output from motion sensor is connected to scope to get both angular displacement and velocity of the motor.

CONCLUSION :

The thermistor model was created and executed.we were able to switch on the fan at a particular temperature as per given conditios.