Week -2
- 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.
For making this model we have used a pulse generator as an input and we have used a battery, a solenoid which is electromechanical device. And ideal translation motion sensor through which we get a output which is displayed on the scope as an output.
The pulse generator is used to generate a square wave pulses at regular intervals. This pulses go to a suite which is controlled. Main external physical signal. If the external physical signal is greater than the threshold, then the switch is closed or else the switch is open. Then we have connected the battery. Negative terminal to the switch and positive terminal to the solenoid. And also we have given the electrical reference and mechanical reference. And we have used ideal transmission motion sensor which measures velocity or displacement in a mechanical translation network. And gives us the output through scope.
The input and output graphs Are attached below along with the model.
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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
For the execution of this model we have used a signal builder, a controlled temperature source. A voltage sensor. Thermistor. A battery. Switch, scope and display.
It's signal builder is used to give an input signal. The signal can be modified based on our criteria. So we are designing it as per the given condition in the question. The picture of signal is attached in below files.
The controlled temperature source is used to maintain an ideal energy source in a thermal network that can maintain a controlled temperature difference regardless of the heat flow rate.
The signal is then given to the thermistor. The batteries are attached with an electrical reference and also a resistor. A voltage sensor is connected across the resistor. A voltage sensor converts voltage measured between any electrical connections into a physical signal proportional to the voltage.
We measured the value of the voltage sensor by using a display. And the value which we get when the temperature is above 25c is set as a threshold value for the switch. So whenever the temperature crosses 25 degrees Celsius the switch turns on or else it stays off. The output of the scope is attached below where we can see that when the temperture crosses 25c the switch is 1 it means it is at on position.