Week -2
- Make a Simulink model of Doorbell using solenoid block with the following details:
In the below 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.
Simulink model developed for the above mentioned case is as shown below:
It uses a pulse generator input, its value is adjusted to get 2 sec on and 2 sec off results.
PS-SL converter block is used to provide the input to electromechanical block which is the physical system here.
Battery,switch,solenoid valve, ideal translational motion sensor blocks frame up the electro-mechanical physical setup.
Proper electrical reference & Mechanical references are given and proper solver configuration is also made.
Scope is used to preview the output.
Pulse generator is set to have 4 secs period and 50% pulse width with 0 phase delay.
Scope output showing plunger values.
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
Solution:
Simulink model for the above case is obtained as shown below:
Uses Thermistor powered by battery and connected via a resistor element.
Signal builder is used to generate input signal with specified conditions of amplitude: 20 °C from 0 to 10 seconds, 27 °C from 10 to 30 seconds, 23 °C from 30 to 50 seconds.
Switch block with 2 constant blocks are used to set the conditions for Fan operation.
Controlled temperature source is used to connect signal builder to thermistor block.
DC motor , rotational sensor , mechanical rotational reference are used at the output side.
Display and scope is used to view the outputs.
After running the model:
Scope output:
Thus the thermistor setup is used to measure the temperature and Dc motor is made to run accordingly.