Week -2

AIM :

Make a Simulink model of Doorbell using solenoid block and thermistor to sense the temperature of a heater & turn on or turn off the fan as per given conditions.

OBJECTIVES :

 1.Make a Simulink model of Doorbell using solenoid block

In the above arrangement, when the switch is closed the electromagnet receives electrical power from the battery and pulls the metal arm to hit the bell producing sound. 

Create a situation where the switch is closed for 2 seconds and then released. Observe the physical movement of the plunger. 

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

Objective 1: 

Make a Simulink model of Doorbell using solenoid block

In doorbell, when the switch is closed Electric current passes from battery. When current passes from conducting wires a magnetic field is generated,Which drugs the plunger in. Due to this bell is ringing.

We are going to use following blocks for doorbell simulink - 

1. Battery- 

Battery is used for electric supply

2. SPST switch-

This is a basic ON/OFF switch and used to connect or Break the connection between two terminals.

3. Solenoid-

Solenoid is a set of coiled wire which acts as an electromagnet when current is passed through it. Basically it converts electrical energy directly into linear mechanical motion.

4. Ideal translational motor sensor-

This is a device which converts an across variable measured between two mechanical translational nodes into a control signal proportional to velocity or position.

Simulink Model of Door Bell : 

Explanation:

1.For door bell simulink we are going to use pulse generator block,batery,switch,solenoid block,ideal translational motion sensor, solver configuration block & scope blocks.

2.We are using pulse generator for input condition given

3.Then next we are using simulink PS convertor block for passing the input signal from Simulink block to simscape block.

3.The input signal is provided from switch,A battery is connected to solenoid

4.When we give electric supply from battery to solenoid, it generates magnetic field in solenoid, due to this plunger movement done.

OUTPUTS:

1.Time vs Amplitude

2.Time vs Velocity

3.Time vs Position

Objective 2 :

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

 

We are going to use following blocks for doorbell simulink -

1.Battery- 

Battery is used for electric supply.

2. Thermistor-

Thermistor is a type of resistor whose electrical resistance varies with changes in temperature. Thermistors are widely used as a way to measure temperature as a thermistor thermometer in many different liquid and ambient air environments. 

3.Resistor-

A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses.

4.Voltage sensor-

Voltage sensor is used to calculate and monitor the amount of voltage in an object. Voltage sensors can determine the AC voltage or DC voltage level.

Simulink model of thermister :

Explanation :

1.In above circuit, signal builder block is used for create access to the signals connected with controlled temperature.We have to give inputs to signal builder.

2.Controlled temperature source is an ideal energy source in thermal network that can maintain a controlled temperature difference regardless of the heat flow rate. 

3.Battery is connected to thermistor for electrical supply.

4.To measure  voltage, voltage sensor is connected to circuit.

5.The switch has 3 ports, two of them are connected with constant blocks, and one of them is connected to voltage sensor.

Output: 

1. Repeating sequence stair - Scope block

Temperature source :

20 degrees (293 K) from 0 to 10 sec

27 degrees (300 K) from 10 to 30 sec

23 degrees (296 K) from 30 to 50 sec

2. Voltage sensor block - Scope 1 block

3.Switch block - Scope 2 block

Coclusion :

1.We understand how to create circuits & how to give output blocks for results for door bell & fan using thermister simulinks.

2.Both simulinks are completed successfully.