Week -2
Objective:
- Make a Simulink model of Doorbell using solenoid block with the following details:
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.
Assume remaining parameters.
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:
For Objective 1:
Simulink model:
Working:
1) Here we use a pulse generator for the input condition given in the question.
2) To pass the input signal from the simulink block to simscape block through the switch, a simulink to PS convertor block is used.
3) The input signal si provided to a switch. Abattery is connected to a solenoid to generate the magnetic field for movement of the plunger and the switch with electrical refrence as a ground.
4) To track the position of the plunger a translation motion sensor is used. The output of the solenoid block from connector R is given to the motion sensor as an input which will ultimately give an output of position that can be observed in the graph through the scope block.
5) Translation reference block is used for fixed point and also solver configuration is provided to solve the model with simscape block. In addition, the display block is applied which shows the output for the last value.
Inputs:
Outputs:
1)
2)
According tothe above example of the output, we can change the various input parameters to get the output with smooth intensity signal.
Result: Here we run the model for 10 sec as it is a stop time provided here. From the graph it acn be seen that due delay of 2 sec at the initial stage, the position of plunger is at 0. But after that, for the next 2 secs, the solenoid will engage and there will be a movement of plunger. Again for 2 sec the position will come to 0 and for the next 2sec plunger will show displacement. This process continues for a total of 10 secs according to the stop time provided.
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For Objective 2:
Simulink model:
Working:
Inputs:
Outputs:
Results:
From The above graph, it can be seen that the fan shows the zero angular velcity for the first 10 seconds which is because fan is in off condition when the temp. is 293K.
When the temp. is 300K between 10 to 30 seconds ,it is observed that the angilar velocity is increased as the fan is moving and when the temp. is 296K between the 30 to 50 seconds, we can see that the fan is again stopped as angular velocity is decreased which will remain constant from 30 to 50 seconds.
Conclusion:
1) For doorbell model, from the graph, it can be concluded that the situation for 2 seconds delay is satisfied and the plunger movement is also observed.
2) For the thermistor model, from the angular velocity graph, we can conclude that the fan is in motion only when thermistor will sense the the temp. greater than that of 25 degree celcius which satisfies the required condition.
Both the simulink model are attached below.