Week -2

1.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.

Aim:

Make a Simulink model of Doorbell using solenoid block

Condition:

swich is closed for 2sec and the released

Simulink Model:

Block use for simulink model:

• Pulse Generator
• Switch
• Solenoid
• Battery
• Ideal Translational Motion Sensor
• Solver Configuration
• Mechanical Translational Reference
• Electrical Reference
• Scope
• PS-simulink converter
• Simulink-PS converter

Theory:

• The pulse generator is used to create square wave pulses at regular intervals of time.The block parameter as shown below

• The switch block used is controlled by external physical signal.If the external signal is greater than the thersold parameter then the switch is closed,otherwise switch is open.
• The positive terminal of switch is connected to battery and the negative terminal is connected to electrical reference.
• The solenoid block is connected with battery and switch.
• C port is connected with mechanical reference and R port connected with ideal translational sensor.
• Scope is connected with pulse generator and ideal translational sensor to get the input and output signal.
• PS-simulink converter is used to convert to physical signal to simulink signal.
• Solver configuration: Each physical network represented by a connected Simscape block diagram requires solver settings information for simulation. The Solver Configuration block specifies the solver parameters that your model needs before you can begin simulation.

Results:

INPUT:

OUTPUT:

Conclusion:

The simulation was run for 10sec and the result obtained is shown above.It can be observed that at each 2sec interval the bell is ringing.

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

Simulink Model:

Block use for simulink Model

• Repeating Sequence Stair
• Controlled Temperature Source
• Thermistor
• Voltage Sensor
• Battery
• Resistor
• Thermal Reference
• Electrical Reference
• Switch
• Solver connfiguration
• Display
• Scope

Theory:

• A Repeating Sequence Stair is given as input to the thermistor through a controlled temperature source.The definite of Repeating Sequence Stair block is given below.

• The sample time is taken as 10sec and the simulation time is take as 50sec because there are 5 temperature condition given for each 10sec interval of time i.e [293, 300, 300, 297, 297]
• Battery and a resistor is connected in the thermistor circuit.
• The voltage sensor was given across the resistor to measure the voltage chande during the different temperature inputs.
• The resistance of this resistor can be set to any value,but it should not be changed onces the thersold voltage is found.
• The two different constant block given to this switch block
• If the simulation run at first time then the display block shows the thersold voltage value.After that this thersold value is putting into the switch block.
• Then once again the simulation is run and we get the output signal.

Result:

INPUT signal:

OUTPUT signal:

Conclusion:

The simulation was run for 50sec and the result obtained is shown above.It can be observed that whenever the temperature goes above the 25 °C i.e. 298K the fan will be turn ON similarly if the temperature goes below the 25 °C i.e. 298K the fan will be turn OFF.