Week -2

Simulink Model Explanation:

• The pulse generator is used to create square wave pulses at regular intervals.

The block waveform parameters amplitude, pulse width, period and phase delay, determine the shape of the output waveform.

• The switch block used is controlled by external physical signal. If the external signal is greater than the threshold parameter then the switch is closed, otherwise switch is open.
• The positive terminal of the switch is connected to switch and the negative terminal is connected to the electrical reference.
• The solenoid block is connected with switch and battery and we will get a completed electrical circuit. The port c is connected with mechanical reference.
• The ideal transitional sensor is connected with solenoid block R to observe the movement of the plunger.
• Scope is connected with the ideal translational sensor to get the output.
• PS-Simulink converter is used to convert the physical signal to Simulink signal.
• Solver configuration: Each physical network represented by a connected simscape blocks requires solver setting information for simulation.

Thermistor

Given Inputs:

Temperature source: 20⁰C from 0-10secs, 27⁰C from 10-30secs, 23⁰C from 32-50secs.

Fan conditions: ON if the temperature above 25⁰C, OFF otherwise.

Simulink model:

Simulink model explanation:

Signal builder blocks used to the input the values as per given conditions.

At point 1, Time=0Seconds, Temperature=293k.

At point 2, Time=10Seconds, Temperature=293k.

At point 3, Time=10Seconds, Temperature=300k.

At point 4, Time=3Seconds, Temperature=300k.

At point 5, Time=30Seconds, Temperature=296k.

At point 6, Time=50Seconds, Temperature=296k.

• Controlled temperature source represents an ideal source of thermal energy, that can maintain a controlled temperature difference regardless of the heat flow rate. The temperature difference is set by the physical signal port S. A positive temperature difference causes the temperature at port B to be greater than the temperature at port A.
• Thermistor is a type resistor whose resistance is based upon temperature.
• A liner resistor is used in order to control the amount of current from the battery.
• The voltage sensor is used to sense the voltage, measured between 2 points into a physical signal.
• Voltage source which represents AC or DC.
• Electrical reference block is given in below.
• Solver configuration is to each physical network represented by A, connected Sims cape block requires solver setting information for simulation.

Results:

Doorbell:

Time period is given is 2Seconds to the pulse generator t open and close the switch.

When the switch is closed the solenoid blocks receives electrical power from the battery and the plunger move from port R to C to hit the bell and produce sound.

Thermistor:

Fro 0 to 10s fan is off condition because temperature is 293k which is below the threshold 298k. After 10s temperature goes to 300k than the switch will be in ON condition as the temperature exceeds 298k. After 30s fan will turn off as the temperature comes down to 296k which is below the threshold temperature of 298k.

From the above conditions, all the values are evaluated.