Week -2

Aim:

1.To make a Simulink model of Doorbell using solenoid block.

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

STUDY-1

Theory:

The doorbell working in the principal of electromagnet. with the use of solenoid. when the switch is closed the power supply is passed through the battery into solenoid. which creates an electromagnetic field.The plunger moves towards the electromagnetic field and hit the bell to produce the sound.

Simulink Model:

Input Parameters:

Input signal:

Model Explanation:

1. The Pulse Generatorblock generates square wave pulses at regular intervals. The block waveform parameters, Amplitude, Pulse Width, Period, andPhase delay, determine the shape of the output waveform. The following diagram shows how each parameter affects the waveform.

2.Positive terminal of the battery is connected to the switch block and the negative terminal is connected to solenoid.

3.Plunger part of the solenoid is connected with Ideal translational motion sensor, we can observe the physical movement of the plunger.

4. Each physical network represented by a connected Simscape block diagram requires solver settings information for simulation. The Solver Configuration block specifies the solver parameters that your model needs before you can begin simulation.

5.The switch block is controlled by the input signal using pulse generator.

6.A scope block is connected to get the output of the model.

Output:

STUDY-2

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

Theory: Thermistor

A thermistor is a type of resistor which has a property of increasing its temperature when the resistance is decrease.

Simulink Model:

Input through repeat sequence stair:

Model Explanation:

1. The Repeating Sequence Stairblock outputs and repeats a stair sequence that you specify with the Vector of output values I have converted the temperature value in kelvin(0-degree=273K).

2. The Controlled Temperature Source block represents an ideal source of thermal energy that is powerful enough to maintain specified temperature difference across the source regardless of the heat flow consumed by the system.

3. The Voltage Sensor block represents an ideal voltage sensor, that is, a device that converts voltage measured between two points of an electrical circuit into a physical signal proportional to the voltage. The voltage sensor is connected with display so that we can get a value of voltage drop. Using voltage drop value=0.01099 is given to threshold value to the switch condition.

4. If the threshold value is greater than zero, the fan will ON at the temperature of 25-degree(298K).

5. A scope block is connected to get the output of the model.

Output:

Conclusion:

STUDY-1

The doorbell model was created and executed. We can observed that there is change in plunger when the power supply is passed into solenoid.

STUDY-2

The thermistor model was created and executed successfully.