Week -2

AIM-

1. To make a simulink model of a Doorbell using solenoid block with given details.

2.To sense the temperature of a heater using Thermistor & turn on or turn off the fan with given conditions.

THEORY -

• Solenoid-: A solenoid is a type of electromagnet,the purpose of which is to generate a controlled magnetic field through a coil wound in a tightly packed helix.The coil can be arranged to produce a uniform magnetic field in a volume of space when an electric current is passed through it.

Above figure showing solenoid.

Above figure shows the real life example of solenoid (Door Bell)

• Simulink model of Doorbell using solenoid block-

Blocks Parameter For Pulse Generator -

Explanation-

• The Pulse Generator block generates square wave pulses at regular intervals.
• The block waveform parameters, Amplitude, Pulse Width , Period , and Phase Delay, determine the shape of the output waveform.

Above figure shows how each parameters effects the waveform.

• Simulink PS-Converter is used to convert input simulink signal into physical signal.
• Scope1 display time domain signals of pulse generator.
• To close the circuit in 2 seconds we use the switch block.Thresold value of switch block is 0.5.
• Solenoid block is used with the plunger arrangement ,the plunger fully in i.e air gap closed at X = 0; and pull in force is assumed to decrease quadratically with magnitude of X.
• C port is connected with mechanical translational refrence .
• The position of plunger is obtained by using ideal translational motion sensor ,value is obtained by using scope.
• The Electrical Reference block represents an electrical ground. Electrical conserving ports of all the blocks that are directly connected to ground must be connected to an Electrical Reference block. A model with electrical elements must contain at least one Electrical Reference block.

RESULT-

1)Obtained From Pulse Generator

Above Figure shows the pulse pattern , initially for 0-2 sec the phase is 0 and also the value of amplitude is 0 till 2 sec.For 2 to 4 sec the amplitude value is 2 , pulse is ON for every 2 seconds.

2)Position Of Plunger

From Above Figure it is observe that bell rung for every 2 sec, result is obtained by using Translational motion sensor.

3) Velocity pysical signal -

Above figure shows for every 2 sec there is deflection which shows the velocity at which plunger hit the bell.

THERMISTOR-

2.To sense the temperature of a heater using Thermistor & turn on or turn off the fan with given conditions.

THEORY

Thermistor - Thermistor is a device which is used for temperature measurement. Thermistor is a type of resistor whose resistance is strongly dependent on temperature.

WORKING PRINCIPLE - Electric Resistance.

CONDITIONS -

1). Temperature Source - 20 degree celsius at 0 to 10 sec

2). Temperature Source - 27 degree celsius at 10 to 30 sec

3). Temperature Source - 23 degree celsius at 30 to 50 sec

SIMULINK BLOCK MODEL-

Result-

Model Explanation-

The fan should be turned ON when the value of temperature is greater than 298 k , we use the voltmeter to find the voltage at different temperature.

For 0 to 10 sec the temperature is 293 K ,For another 10 to 30 sec the temperature is 300 K for which the fan should be turned ON .

For 30 to 50 sec the temperature is 298 K and the fan condition is OFF.

Switch is provided to perate these condition we have given it a threshold value of 0.01108.The fan will ON when the threshold value will be more then 0.01108 and it is set for 298K and for time range is 10 to 30 sec.

The scope is provided to see the result.

SCOPE RESULT-

From 0-10 seconds fan is OFF because temperature is 293K which is below 298 K ,After 10 seconds it will goes to 300 K so fan will turn ON because temperature exceeds 298 K .After 30 seconds fan will turn OFF because temperature goes 296 K which is less than 298 K.