Week -2
AIM
TO CREATE A SIMULINK BLOCK DIAGRAM OF DOORBELL USING SOLENOIDAL BLOCK.
BY USING A THERMISTOR SENSE THE TEMPERATURE OF A HERATER AND MAKE IT SWITCH ON AND OF THE FAN ACCORDING TO THE TEMPERATURE.
QUESTION-01
MAKE A SIMULINK MODEL OF DOORBELL USING A SOLENOID BLOCK WITH THE FOLLOWING DETAILS.
IN THE ARRANGEMENT,WHEN THE SWITCH IS CLOSED THE ELECTROMAGNET RECEIVES ELECTRICAL POWER AND PULLS THE METAL ARM TO HIT THE BELL PRODUCING SOUND.
CREATE A SITUATION WHERE THE SWITCH IS CLOSED FOR 2 SEC AND THEN RELEASED. OBSERVE THE PHYSICAL MOVEMENT OF THE PLUNGER.
EXPLANATION:
FIRST THE INPUT IS GIVEN WITH THE HELP OF PULSE GENERATOR AND ITS CONNECTED TO ELECTRICAL SWITCH WITH THE HELP OF A SIMULINK-PS CONVERTER AND THE INPUT IS OBSERVED
THEN THE SOLVER CONFIGURATION BLOCK IS CONNECTED TO THE SWITCH . A BATTERY BLOCK IS DEFINED FOR VOLTAGE SOURCE.
A BATTERY IS CONNECTED TO AN ELECTRICAL SWITCH AND THE SWITCH IS CONNECTED TO THE SOLENOID TO COMPLETE THE CIRCUIT.
THEN THE SOLENOIDAL BLOCK IS CONNECTED TO AN IDEAL TRANSLATION MOTION SENSOR TO MEASURE THE TRANSLATION MOTION OF THE SOLENOID, THE TRANSLATION MOTION OF THE BELL IS OBSERVED BY CONNECTING TO THE SCOPE WITH THE PS- SIMULINK CONVERTER.
ELECTRICAL AND MECHANICAL TRANSLATION REFERENCE CONNECTED TO EARTHING.
STOP TIME IS GIVEN AS 20 SEC.
INITIAL POSITION OF THE IDEAL TRANSLATIONAL MOTION SENSOR IS GIVEN AS 5 SEC
SIMULINK BLOCK :
OUTPUT OF THE SIMULINK BLOCK:
QUESTION-2
USE A THERMISTOR TO SENSE THE TEMPERATURE OF S HEATER AND TURN ON OR TURN OFF THE FAN AS PER BELOW CONDITIONS:
TEMPERATURE SOURCE IS FOR 20 DEG CELSIUS FROM 0 TO 10 SECS, 27 DEG CELSIUS FROM 10 TO 30 SECONDS, 23 DEG CELSIUS FROM 30 TO 50 SECONDS
FAN CONDITIONS: ON IF THR TEMPERATURE ABOVE 25 DEG CELSIUS TO BE IN OFF CONDITION.
WHEN THE DOOR BELL BUTTON IS PRESSED, AN ELECTRICAL CIRCUIT IS CLOSED,WHICH LEADS TO THE FLOWING OF ELECTRIC CURRENT THROUGH THE ELECTROMAGNET. THE CURRENT THEN PASSES THROUGH THE ELECTROMAGNETIC WIRE WINDING. A MAGNETIC FIELD IS GENERATED AS A RESULT, WHICH IS USED TO DRIVE A SOUND MAKING MECHANISM. DIFFERENT TYPES OF SOUND MAKING MECHANISMS ARE USED TO GENERATE DIFFERENT SORTS OF NOISES.
EXPLANATION:
INPUT SIGNAL IS GIVEN WITH THE HELP OF REPEATING SEQUENCE BLOCK.
THE INPUT SIGNAL BLOCK IS CONNECT TO ‘S’ PORT OF THR CONTROLLED TEMPERATURE SOURCE BLOCK WITH THE HELP OF A SIMULINK-PS CONVERTER. THE ‘B’ PORT OF THE CONTROLLED TEMPERATURE SOURCE IS CONNECTED TO THE ‘A’ PORT OF THERMISTOR.
A SCOPE IS CONNECTED TO THE INPUT SIGNAL OF OBSERVE THE INPUT.
THEN WE CONNECT A RESISTOR BLOCK AND CONNECT IT TO A VOLTAGE BLOCK IN A SERIES TO MEASURE THE VOLTAGE FLOWING THROUGH THE RESISTOR.
DISPLAY BLOCK IS CONNECTED TO ‘V’ OF THE VOLTAGE SENSOR WITH THE HELP OF A PS-SIMULINK CONVERTER TO DISPLAY THE OUTPUT.
A CONDITIONAL SWITCH BLOCK WITH 2 CONSTANT BLOCKS OF VALUE ‘0’ AND ‘T’ IS CONNECTED TO THE ‘V’ PORT OF THE VOLTAGE SENSOR.
THEN THE THRESHOLD OF THE SWITCH IS CALCULATED BY THE THERMISTOR EQUATION.
8.29 OHMS IS CALCULATED AS THE THRESHOLD AT 25 DEG CELSIUS AN IT GIVEN AS THRESHOLD FOR SWITCH.
T1 IS THE FIRST TEMPERATURE POINT IN KELVIN
T2 IS THE SECOND TEMPERATURE POINT IN KELVIN
R1 IS THE THERMISTOR RESISTANCE AT TEMPERATURE T1 IN OHMS.
R2 IS THE THERMISTORS RESISTANCE AT TEMPERATURE T2 IN OHMS.
THE CONDITIONAL SWITCH BLOCK IS CONNECT TO A SCOPE TO DISPLAY THE GRAPH AND THE OUTPUT OF SWITCH IS CONNECTED TO A LAMP. THE LAMP GLOWS RED IF THE RESISTANCE ACROSS IS LESS THAN THE SWITCH THRESHOLD MEANING THE FAN IT OFF, IF THE RESISTANCE ACROSS IS HIGHER THAN THE SWITCH THRESH0LD THE LAMP GLOWS GREEN MEANING THE FAN IS ON.
THERMAL REFERENCE AND ELECTRICAL REFERENCE IS CONNECTED TO PROVIDE EARTHING,
THE INITIAL STOP TIME IS GIVEN AS 20 SEC.
SIMULINK MODEL:
INPUT SIGNAL
OUTPUT SCOPE:
CONCLUSION:
THUS, BOTH THE OBJECTIVES WERE ACHIEVED SUCCESSFULLY. SIMILAR APPROACH CAN BE USED FOR SIMULATING OTHER PHYSICAL DEVICES USING THE SIMULINK.