Week -2

1

AIM:

to make a Simulink model of a doorbell using solenoid block

SIMULINK MODEL EXPLANATION:

• the pulse generator is used to create a square wave pulse at regular intervals. the blocks waveform parameters. amplitude, pulse width, period, and phase delay. determine the shape of the output waveform
• the switch block used is controlled by an external physical signal. if the external signal is greater than the threshold parameter then the switch is closed otherwise the switch is open.
• the positive terminal of the switch is connected to the switch and the negative terminal is connected to the electrical reference.
• the solenoid block is connected with the switch and battery. we will get a complete electrical circuit. the port c is connected with the mechanical reference.
• the ideal translational sensor is connected with the solenoid block R to observe the movement of the plunger.
• the scope is connected with the ideal translational sensor to get the output.
• PS-Simulink converter is used to convert the physical signal to a Simulink signal.

solver configuration: each physical network represented by a connected simscape block requires solver setting information for the simulation.

RESULT:

time period is given is 2s to the pulse generator to 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 proceed to sound

2

use a thermistor to sense the temperature of a heater and turn on or turn off the fan

AIM:

to use a thermistor to sense the temperature of a heater and turn on and turn off the fan

THERMISTOR

given inputs:

temperature source 20 degrees Celcius from 0 to 10 seconds, 27 degrees Celcius from 10 to 30 seconds, 25 degrees Celcius from 30 to 50 seconds

fan conditions: on if the temperature is above 25 degrees Celcius. off if the temperature is less than the 25 degrees Celcius

Simulink model explantation:

signal builder block is used to input the values as per given conditions

at point 1, time=0 seconds,temperature=293k

at point 2, time=10 seconds,temperature=293k

at point 3, time=10 seconds,temperature=300k

at point 4, time=30 seconds,temperature=300k

at point 5, time=30 seconds,temperature=296k

at point 6, time=50 seconds,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.
• a thermistor is a type of resistor whose resistance is based upon temperature
• a linear resistor is used in order to control the amount of current from the battery.
• the voltage sensor is used to convert the voltage measured between two points into a physical signal
• voltage source which represents dc or ac.
• electrical reference block is given

solver configuration:

each physical network is represented by a connected simscape block that requires solver setting information for the simulation

RESULT:

for 0 to 10 seconds fan is OFF condition because temperature is 293k which is below the threshold of 298k. after 10s temperature goes to 300k then the switch will be in on condition as the temperature exceeds 298k. after 30s fan will turn off as the temperature goes less than the threshold temperature.