Week -2

1.AIM:-Make a Simulink model of Doorbell using solenoid block.

• SIMULINK MODEL:-

• SIMULINK MODEL DISCRIPATION:

• As shown in above model,we are using pulse generator for square wave signal generation at regular intervals.In this block configuration,we have to set the value of pulse width,period and phase dealy.
• simulink-PS convertor is use for convert the signal into physical block.

• As shown in above picture,we are giving 2 sec of phase dealy and peroid 4 sec as per requirement.
• switch block is controlled by external physical system,when it`s value is goes up to thershold then switch is closed and electrical input is given to the solenoid.
• fixed solver is used for solve the model at regular time intervals.
• Positive terminal of battery is connected to the positive terminal of switch and negative terminal of battery is connected to the electrical reference.
• Solenoid block is connected between switch and battery and will get complete electric circuit.The C port of solenoid is connected with mechanical reference.
• The R port of solenoid is connected to ideal translational motion sensor to observe the movement of plunger.
• Scope is connected with the ideal translational sensor to get the ouput.
• PS-Simulink converter is used to convert the physical signal to simulink signal.

• OBSERVATION:-

• As shown in figure 1,Time period is 2 sec to pulse generator to open and close the switch.when switch is closed the solenoid gets electrical power from battery and plunger move from R port to C to hit bell and produce sound.

• As shown in above figure,the spikes are generated at every 2 sec.So that at every to 2 seconds we are getting movement from plunger.

• CONCULSION:-

So by using Solenoid block we can easily get output by giving input at electrical side of solenoid and also get pulnger movement of solenoid.

2.AIM:-Use a thermistor to sense the temperature of a heater & turn on or turn off the fan.

THERMISTOR:-

It works on principal of change in resistance due to a change in temperature.It made of semiconductor materials Such as nickel,manganese,copper,cobalt etc.

SIMULINK MODEL:-

SIMULINK MODEL DESCRIPATION:-

• Here,as shown in above figure,signal builder is used for built a signal as per requirement which is for 293 K from 0 to 10 seconds, 300 K from 10 to 30 seconds, 296 K from 30 to 50 seconds.

• Simulink - PS convertor is used to convert the simulink signal to physical signal.
• Controlled Temperature source represents an ideal source of thermal energy.physical input given to the port S of the block.A positive temperature difference causes the temperature at port B to be greater than the temperature at port A.
• Thermistor is a type resistor whose resistace is vary with the temperature.
• A linear resistance is used to control the amount of current from the battery.
• The positive terminal of battery is connected to the thermistor and negative teminal is connected to the electrical reference.
• Fixed solver is connected to the negative of thermistor to solve the model at regular time interval.
• Voltage sensor is connected parallel with the thermistor for sense the voltage across the thermistor.
• Output of volatge sensor is given to the PS-simulink convertor to convert the physical into simulink signal.
• Switch block is used for turn on and off the fun as per given conditon which is ON if the temperature above 25 °C(298k), OFF otherwise.
• Scopes are connected for observing the result.

• OBSERVATION:-

• From above figure, we are getting our signal from signal builder for 50 sec.

• From above result,the voltage of thermistor as per the time interval given to the signal builder.

• When the simulink model is run for 9 seconds the lump is glow as red because the tempature for 0-10 second is 293 K i.e.below the 298 K. So that the fan is in off condition.

• When the simulink model is run for 11 seconds the lump is glow as green because the tempature for 10-30 second is 300 K i.e.Above the 298 K. So that the fan is in on condition.

• When the simulink model is run for 31 seconds the lump is glow as red because the tempature for 30-50 seconds is 296 K i.e.below the 298 K. So that the fan is in off condition.

• From above result,we getting the switch output waveform for given fan on and off condition,for 0-10 seconds fan is off,10-30 seconds fan is on,30-50 seconds fan reamains off.

• CONCULSION:-

So by using this model we can easily trigger a fan for any time interval by building a signal of signal builder.