1. REMOTE CONTROL FOR HOME APPLIANCES
SUBMITTED BY:
ABHIJITH SJ (501)
ANAND M (511)
ASHWIN VINOO (522)
T6A , SCTCE , TRIVANDRUM
BABILU SANKAR (527)

2. INTRODUCTION
THE AIM OF OUR PROJECT IS TO DESIGN A WALL MOUNTABLE DEVICE TO AID THE AUTOMATION OF HOUSEHOLD DEVICES.
AC MAINS
THE DEVICE SENSES INFRARED RADIATION FROM ANY COMMON INFRARED BASED TV REMOTE
AND THUS SWITHES ON/OFF THE APPLIANCE CONNECTED TO IT .
NOTE: IF DC POWER IS FED INSTEAD OF AC,THE DEVICE CAN BE USED TO CONTROL LEDS ,TOY MOTORS ETC.
DEVICE INPUTS
DEVICE OUTPUTS
1. AC MAINS LIVE
1. APPLIANCE LIVE
2. AC MAINS NEUTRAL
2. APPLIANCE NEUTRAL
3.INFRARED RADIATION
(TV REMOTE SIGNAL)
3. RED LED INDICATING THAT THE APPLIANCE IS OFF.
4.GREEN LED INDICATING THAT THE APPLIANCE IS ON
The device can be activated by any button on a tv remote

3. BASIC CONCEPTS FOR SENSING THE INFRARED SIGNALS WE USE TSOP1738
MOST INFRARED TV REMOTES FOLLOW PWM FORMATS (LIKE NEC,SONY ETC)
TSOP1738 IS AN INFRARED SENSOR WHICH OUTPUTS ARE 0V IF INFRARED RADIATION IS DETECTED AND 5V OTHERWISE.
FOR SWITCHING THE AC APPLIANCE ON/OFF WE USE 6V RELAY
THE RELAY IS BASICALLY A SWITCH .
NORMALLY COM IS CONNECTED TO NC PIN .
BUT WHEN A 6V DC VOLTAGE IS APPLIED IN BETWEEN THE COILS,
COM GETS CONNECTED TO NO PIN.
THUS USING A RELAY AC MAINS SUPPLY MAY BE SWITCHED ON/OFF USING A SMALL DC VOLTAGE .

4. THE CIRCUIT CAN BE DIVIDED INTO TWO PARTS:
1) THE CIRCUIT FOR SENSING THE REMOTE AND CONTROLLING THE AC APPLIANCE L
JOHNSON’S COUNTER
(CD4017)
RELAY DRIVING CIRCUITRY
CLK SIGNAL GENERATION CIRCUITRY
INFRARED SENSOR
RELAY
230V AC 50HZ N
WHEN A TV REMOTE’S BUTTON IS PRESSED ,THE INFRARED SENSOR GENERATES A PWM SIGNAL. A LARGE CAPACITANCE CONNECTED TO THE OUTPUT OF THE SENSOR, FILTERS THE SIGNALS TO GET A CONTINUOUS DC VOLTAGE. THIS CREATES THE CLOCK SIGNAL FOR THE CD4017 USING A BC558 TRANSISTOR.
APPLIANCE
INITIALLY THE COUNTER COUNTS 0,HENCE THE RED LED AT O0 PIN IS ON.WHEN A CLK SIGNAL IS DETECTED THE GREEN LED AT O1 PIN BECOMES ON AND THE RED LED OFF. THIS ALSO DRIVES THE RELAY VIA A BC548 TRANSISTOR.
(SINCE O3 PIN IS CONNECTED TO THE RESET PIN ANOTHER REMOTE SIGNAL WILL RESET THE CD4017 AND THE RELAY WILL BE DEACTIVATED).
THE RELAY WHEN ACTIVATED,SWITCHES ON OUR HOME APPLIANCES(BULBS,FANS….)

5. 2) THE CIRCUIT FOR GENERATING 6V DC POWER FROM MAINS
9-0 TRANSF-ORMER
BRIDGE RECTIFIER
CAPACITOR FILTER
L7806
6V VOLTAGE REGULATOR
AC MAINS
CIRCUIT
THE AC MAINS SUPPLY IS FED TO A 9V TRANSFORMER AND ITS OUTPUT IS RECTIFIED WITH THE HELP OF A BRIDGE RECTIFIER.
A CAPACITOR FILTER SMOOTHENS THE DC VOLTAGE,AND THEN IT IS FED TO L7806,A 6V VOLTAGE REGULATOR.
THUS A CONSTANT 6V POWER SUPPLY FOR THE EARLIER CIRCUIT IS OBTAINED.
COMPONENTS USED AND EXPECTED COST:
CD4017,TSOP1738,L7806,BC548,BC558,9V TRANSFORMER,6V RELAY,100W 230V BULB,RED AND GREEN LEDS,5 X IN4007,2 X 1000µF ,100µF,0.1µF ELECTROLYTIC CAPACITORS,47E,300E,1K AND 220K.
ESTIMATED COST OF DESIGN: RS 350

6. CIRCUIT DIAGRAM +6v N L GND
CIRCUITRY FOR SENSING REMOTE AND CONTROLLING THE RELAY
CIRCUIT DIAGRAM
6V POWER SUPPLY CIRCUITRY
+6v 3 1
L7806 2
IN4007
IN4007 + +
IN4007
IN4007
1000uf
1000uf
9-0 transformer 500ma N L
230V AC 50HZ
GND

7. FRONT PANEL DESIGN DEVICE NAME METAL HINGES FOR NAILING ONTO WALLS
REMOTE SENSING APPLIANCE CONTROL UNIT L L N N
LIVE AND NEUTRAL WIRE TOWARDS APPLIANCE
AC MAINS LIVE AND NEUTRAL WIRE
RED LED INDICATING THE APPLIANCE IS OFF
GREEN LED INDICATING THE APPLIANCE IS ON
OPENING FOR IR SENSOR

8. PCB DEVELOPMENT AND SOLDERING
Step 2:
Print the PCB layout on any A4 white paper using laser printer.
Step1:
Design PCB in orcad PCB designing software.
Step 4:
Take copper clad PCB board and clean its surface using fine grade polish paper.
Step 3:
Redo the above step with a PCB printing sheet covering the printed area on the A4 whit paper.
Step 5:
Put the PCB Printing Sheet on the PCB and to transfer the print, iron it with the household iron.
Step 6:
Peal off the PCB Printing Sheet carefully under cold running water from the PCB board.

9. Step 8: Step 7: Step 9: Step 10: Step 11:
Clean the masking of the itched PCB using fine grade polish paper.
Step 7:
Itch the PCB using Ferrous Chloride (Fe2Cl3) solution.
Step 9:
Drill the holes with appropriate drills and bits.
Step 10:
Apply flux to the ends of all components after cleaning with a sand paper . Then solder in the components using solder and a soldering iron.
Step 11:
Mask the copper track with the solder to increase the life of the PCB.

10. NAWAS ELECTRONICS LAB MANUALS (VOL 1 & 2)
REFERENCES
NAWAS ELECTRONICS LAB MANUALS (VOL 1 & 2)
THE END