Week -2

1) Make a simulink model of Door bell using solenoid block.

• Solenoid is electromagnetic device. it reacts when some current is applied to coil. Here, when switch is on with help of pulse generator current passes through coils and it helps to move plunger, which results into ringing sound of doorbell.

• Simulink model:-
• Here, simulink model shows, the working if doorbell. As it was asked to operate doorbell at every 2 seconds. Pulse generator id used for it.
• Also, this model is combination of electrical and mechnical blocks the PS-simulink convertor and simulink-ps convertor as used. Because, it is essentail of convert the signal for proper understanding of it.

Pulse generator:-

Here, we have set the amplitude to 1 and also the pulse with is 50 % , with period of 4 seconds.

Output Waveform:-

As it can be observed from above diagram, that when pulse is applied to magnetic coil, the doorbell operates for every 2 seconds. The movement of plunger can be seen in the waveform.

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.

Here, we have different block for making the model as per the requirement.

1) signal builder.

2) controlled temperature source.

3) thermistor

4) voltage sensor.

5) switch.

1) Signal builder:- it is used to generate different types of signal for the input. The picture of it is shown below.

2) Temperature controlled source:- it gives output according to input provided in the form of temperature through the signal builder.

3) thermistor:- it is device which converts temperature signal into electrical signal for further analysis.

4) voltage sensor:-The block represents an ideal voltage sensor, that is, a device that converts voltage measured between any electrical connections into a physical signal proportional to the voltage.

Here is the simulink model for the temperature controlled fan.Now , signal builder generates input signal, which goes into controlled temperature source for the maintaining the signal, even the temperature is changing.As the thermistor gives output to voltage sensor, according to the condition the switch operates. the fan is on/off as per the signal condition.

The output waveform:-