Week -2

Aim:

1. To make a simulink model of doorbell using soleniod block
2. To make a simulink model of a thermister to sense the temperature of heater and turn on or off the fan as pet the temperature conditions.

Objective 1

For the given arrangement, Simulink the model of Door bell using solenoid block with given details

Condition A

To create a situation where the switch is closed for 2 seconds and then released, obserb physical movement of the plunger and to assume remaining parameters.

Condition B

When the switch is closed the electromagnet not receives electrical power from the battery and pulls the metal arm to hit the bell producing sound.

Theary content:

Model Blocks used:

Solenaoid

A solenoid is a device comprised of a coil of wire, the housing and moveable plunger (armature). When an electrical current is introduced, a magnetic field forms around the coil which draws plunger in. More simply it convets electrical energy onto mechanical work.

Ideal translational motion sensor:

The ideal translational motion sensor block represents a device that controls on accross variable measured between two mechanical translational nodes into a control singnal proportional to velocity or position. The sensor is ideal since it does not account for inertia, friction, delays, energy consumption, and so on.

Battery:

A Battery is a device that stores chemical energy and convert it into electricity.

Pulse generator:

Time based is recommended for use with a variable step solver, while sample based is recommended for use with a fixed step solver or within a discrete portion of a model using a variable step solver.

SPST Switch:

A SPST switch is a switch that only has a single input and can connect only one output.

Simulink-PS converter:

Converts the simulink input singnal to a physical signal.

PS-simulink converter:

Converts the physical signal into a simulink input signal

Scope:

Dispalys input signlals with respect to simulation time.

Solver configuration:

Defines solver settings, to use for simulation.

Output:

• The following is the output plot of the pulse generator, we can obserb that, the signal is turn for every 2 seconds alternatively. Now we created a situation where switch is closed for every 2 seconds. Thus we achieved required input.

• We have found that when the switch is closed the electromagnet receives electrical power from the battery and pulls metal arm to hit the bell produsing sound shown below.

Objective-2:

To make simulink model of a thermister to sense the temperature of heater and turn on or off the fan as per the given temperature conditions.

Temperature conditions:

At 20°c from 0 to 10 seconds

At 27°c from 10 to 30 seconds

A 23°c from 30 to 50 seconds

Fan condition:

On if tempersture is above 25°c

Off otherwise.

Theory and content:

Blocks used:

Signal Builder:

Create and generate interchangeble groups of signals whose waveforms are piecewise linear.

Here Temperature °c is converted into kelvins.

Now,

• Temperatures of 20°c at 0 second is 293.15k
• Temperatures of 20°c at 10 second is 293.15k
• Temperatures of 27°c at 10 second is 300.15k
• Temperatures of 27°c at 30 second is 300.15k
• Temperatures of 23°c at 30 second is 296.15k
• Temperatures of 23°c at 50 second is 296.15k

Temperature source:

The temperature source block represents an ideal source of thermal energy that is powerful enough to maintain specified temperature at its outlet regardless of the heat flow consumed by the system.

Resistor:

A resistor is a passive two terminal electrical component that implements electrical resistances as a circuit element. In electronic circuits resistors are used to reduce current flow.

Voltage sensor:

A voltage sensor is a sensor used to caluclate and monitor the amount of voltage in an object.

Battery:

A Battery is a device that stores chemical energy and convert it into electricity.

switch:

The block represents a switch controlled by an external physical signal

Simulink-PS converter:

Converts the simulink input singnal to a physical signal.

PS-simulink converter:

Converts the physical signal into a simulink input signal

Scope:

Dispalys input signlals with respect to simulation time.

• For threshold value we taken nearly average of input signal from scope1.

Solver configuration:

Defines solver settings, to use for simulation.

Output:

We succefully done A simulink model of a Thermistor is to sense the temperature of heater and turn on or off the fan as per given temperature conditions.