SETH JAI PARKASH POLYTECHNIC

DAMLA (YAMUNA NAGAR)

SUMMER TRAINING IN

SESSION 2004-07

PREPARED BY:-

SOURAV SINGH : 041515050

DEPARTMENT OF INST. & CONTROL, ENGINEERINGSETH JAI PARKASH POLYTECHNIC DAMLA

(YAMUNA NAGAR)

S.NO. TITAL

1. CERTIFICAT

2. ACKNOWLEDGEMENT

3. INTRODUCTION

4. CIRCUIT DIAGRAM

5. CIRCUIT DIAGRAM DESCRIPTION

6. WORKING OF CIRCUIT

7. BLOCK DIAGRAM

8. PCB DESIGNING

9. IC DETAILS

10. LIST OF COMPONENTS

11. INTRUMENTS

12. FAULT FINDING & TESTING

13. PRECATION

INDEX

ACKNOWLEDGMENT

To secced in any field, the most essential requirment are inspiration and guidance. As

inspration wprlds up, dedication and guidence helps us at very steps in achiving our goal, so

inspiration and guidence is always thanked and respected by deep jeeling of heart

ER.VIPPAN UPPAL of Electronic & communication in SETH JAI PARKASH

POLYTECHNIC DAMLA (YAMUNA NAGAR)

PARVEEN KAUSHIK 031510038

PARVEEN KUMAR 031510039

RISHI PAL 031510049

PERFACE

Electronics & Communication has commanding position in all world technolozy. The

Electronics equipment requie very small power as compare to eletrical & mechinical

equipment and they are very noisy. Our project deals with the utilization of telephone set for

switching on and off an electrical device without moving from our place.

CERTIFICATE

Certified that the project entitled “TELEPHONE CONTROLLED REMOTE SWITCH.”

which is being submitted successfully in.

PARVEEN KAUSHIK 031510038

PARVEEN KUMAR 031510039

RISHI PAL 031510049

Final years students of ELECTRONICS & COMMUNICATION (2003-06) for the partical

fulfillment for the award of Diploma in a bonafied record of work done by them under our

supervision and guidence.

We hope that there future work shall reflact same spirit of initative enthasias and presence.

We wise them every success in life.

GUIDED BY:-

SH. V.M. KALRA ER. VIPPEN UPPAL ER. RAJESH GARG

H.O.D Project Guide Lecturer

INTRODUCTION

TELEPHONE CONTROLLED REMOTE SWITCH

The project deals with the utilization of telephone set for switching on or off any electrically

operated device without away from your place. In order worlds it is used for remote

switching of an electrical device.

The ckt of the project doesn’t require any physical connection with conventional telephone

lines. Hence the normal operation of telephone set in not effected. This ckt only senses the

coded ring signal send by telephone. One should contact the distant telephone by dialing the

number of that telephone. The decoder ckt in the project decodes only the ring sound & not

the dialed no.

For switching on the ckt life the hand set & dial the distant phone no. after hearing two ring

tones put back hand set on credit. Wait for 50s amd again lift the hand set and dial the no.

again hearing after two ring tones put hand set on credit. If a valid code is sensed by mic it

detcts the reciebed signal and this signal is passed through amplifier and timing stage to raise

the level of signal sufficient to drive relay. Once relay is activited it remainis its positin

unless power sulpply is switched off.

BLOCK DIAGRAM

BLOCK DIAGRAM OF TELEPHONE CONTROLLED REMOTE SWITCH

CONDENSORMIC

COMPARATOR MMV 1 [L2s] COUNTER LOGIC

DECODE CKT

MMV 3 [50 s]

ELECTRICAL SEVICE

MMV 2[2 MINUTE]

RELAY DRIVER

RELAY

DESCRIPTION OF BLOCK DIAGRAM: -

(1) Detector

(2) Timing & Control logier

(3) Relay drier unit

(!) Detector: - The detector stage comprises of mice c condenser & a comparator

combination. The incoming ring signal is detected by the condenser mice & o/p of condenser

compared with the reference outage of comparator. O/p of condendenser mice is connected

to inverting terminal of comparator. In normal case, o/p of comparator is high as non-

inserting terminal is sufficiently high {+V} as compared to non-inserting terminal. But

when the signal defected by condenser is applied to comparator, it o/p transits from higher to

lower state. This higher to lower transaction trigger IC, &IC2<IC3. Which are constable

multiuibrators of diff. Duration.

(!!) Timing & Control Logic: This unit consists of

(a) 3monostable multiuibrators of diff, duration

(b) Counter

(c) Logic decodes circuit.

Monostable Multiusibrator

This out put of comparator triggers triggers the monostable multiuibrator

MVV1MMV2.MMV,is used to generate only 1 pulse during 1 second of ring signal is

separated by a time of 2second . Hence duration of o/p of MMV1is kept more than

1seconds but less than 2seconds .

The MMV2 is used to enable the counter for 2 minutes . It also resets the

counter, if valid code is not received.

The MMV3 is used to reset the counter, if the delay between pairs

signal is less than 50s.

Counter :-

The counter works in response to the o/p pulses of monostable multiuib raters .It

automatically resets by MMV3 if invalid code is received It o/p MMV2

Is count. IfMMV2 o/p is low reset of counter is enabled it is forced to counter is enabled it

is forced to count zerp.

Decoder ckt:-

When counter reaches the count of two the decoder ckt triggers the timer

IC8CMMV3whose o/p is goes high for 50seconds . After 50s period , count 3&4 takes place

After 4count, IC8 is again triggered &after 50s delay relay drive ckt is activated.

Relay Driver ckt:-

It works in relation to logic to logic decoder ckt &drives the relay in on off

state as per requirement .

CIRCUIT DETAILS

Schematic diagram of the ckt is given in fig. While the power supply ckt is given separately.

The wave froms available at various points of set diagran are shown in the timing diagram.

For bravity, the ring wave CAI is shown continuous for each ring without showing the inter

mediate 0.2 second break.

WORKING

For the ckt to switch on cor off the electrical desice, a special code is required to be sent.

The valid code consists of two ring of the telephone followed by a predetermined delay (50

second) and again two more ring. But code must be sent with two minetes.

If are sent three or more rings first time unstead of two rings then the circuit automatically

resets to count zero. But if and only if we send another two rings after the predetermited

delay of 50 seconds then the ckt activates a relay which can be used for her switching on or

off at any electrically operated device.

Once the relay is activated, it latches it self through one of the its own pair of contacts. Once

enerigsed, the relay con only be deactivated by switching off power supply to circuit. The

use of the relay contacts for latching makes the ckt operation more reliable. The ring

soundfrom telephone set as picked up by the condeneer is couplet to the increting terminat of

comparator (LM339). The non-inverting terminal of comparator is returned to a sufficienty

high _ve voltge with the help of preset VRI so that the xomparator remains in high state and

is not affected by the noise.

Whehever ring signal is detedted by microphone the voltage at inverting terming passes

aboue the non-inverting terminal voltage and, as a results, the output of comparator drops

from high level. This high to low going output of comp arator triggers timers ic2 & ic3 (both

ne555) simultaneously. The+ve going monopulses at the output of ic2 & ic3 stay high for

stipulated durations of 1.2 second & 2 minutes, respectively. The pulse widths may be

adjusted, as necessary, using presets vr2 & vr3 respectively.

Refer timing waveforms (B) & (C) in fig. The duration of output pulse of ic2 I so adjusted

that it remains high for a period greater than that of one ring (I see) but terminates before the

start of the next ring.

This output of IC2 server as clock for counter OC4 (742592) to advance.

IC3 contact counter IC4 through its resets terminals. When output by IC3 is low, it forces

the reset. The ring sound form telephone set as picked up by the condeneer is couplet to the

incerting terminat of comparator (LM339). The non-inverting terminal of comparator is

returned to a sufficienty high+ve voltage with the help of preset VRI so that in the

comparator reamins high and not is not affected by the noise.

Whenever ring singl is detected by microphone the voltage at inverting terminal passes

above the non-inverting terminal voltage and, as a results, the output of comparator drops

from high level to low level. This high to low going output of comparator triggers tomers ic2

&ic3 (both ne555) somultaneously. The+ve going monopulses at the output of ic2 & ic3 stay

high for stipulated durations of 1.2 seconds & 2 minutes, respectibely. The pluse widths may

be adjusted, as nesessary, using presets vr2 & vr3 respectively.

Refer timing waveforms (B) & (C) in fig. The duration of output puse of ic2 is so adjusted

that it remains high for for a period greater than that of one ring (I see) but terminates before

the start of the next ring. This output of IC2 server as clock for counter IC4 (742592) to

advance.

IC3 controls counter IC4 through its reset terminals . when output by IC3 stages at count No.

when output of IC3 goes high it enables the counter IC4 for a period of two minutes (to

count).

When counter IC4 reaches the count of two the decoder circuit tiggers the timers ICB whose

output goes high for 50 seconds as shown in wave form (D). during this period of 50 seconds

is Ic4 receives a third clock pulse, counter IC4 resets. VTa gates N4,M2& N1 to counters if

and `ble than an electronic latch circuit. The ring sound from telephone set as picked up the

condeneer is couplet to the incerting of compartor (LM339). The non-inverting terminal of

comparator is returned to a sufficiently high_ve voltage with the help of preset VRI so that

in the comparator remains high and is not affected by the noise.

Whenever ring signal is detected by microphone the voltage at inverting terminal passes

above the non-inverting terminal voltage and as a results, the output of comparator drops

fom high level to low level. This high to low going output of ic2 & ic3 stay high for

stipulated durations of 1.2 seconds & 2 minutes, respectively. The pulse widths may be

adjusted as necessary using presets vr2& vr3 respectively.

Refer timing waveforms (B) & (C) in fig. The duration of put puse of ic2 is so adjusted that

it remains high for a period greater than that of one ring (I see) but terminates before the start

of the next ring. This output of IC2 server as clock for counter IC4(742592) to advance. IC3

controls counter IC4 through its reset terminals. When output by IC3 is low, it forces the

reset terminalsb by IC4 to go to logoc 1 state via NAND gate N1. thus counter Ic4 stages

No. When output of Ic goes high it enables the counter Ic4 for period of two minutes (to

counter).

When counter IC4 reaches the counter the counter of two the decoder circuit tigger the

timers ICB whose output goes high for 50 secounds as shown in wave form (D). during this

period of 50 seconds is Ic4 receivers a third clock pulse, counter IC4 resets. VTa gates

N4,M2&N1 to counter if and when counter IC4 reaches the coujnt of 4 then IC8 is again

triggered and after a 50 second delay relay RlI is achvated 4 latched. For latching tanchon,

one det of contads of relay connected as shown in figure are used.

For ease of understanding the operation of decoder circuit logic levels at various points of

the circuit after given in truth table. LED in dicators are used at various points in the circut

for eary adjustment & tesing All suchs point are monked in circuit diagram.

PCB MANUFACTURING

PCB designing determins the size of project.

Various steps involved in PCB designing are:-

1. Layout Dsigning:-

It is the drawing on paper which provides a complete information

about the compenents outline, components holes & their inter connection.

2 Artwork Designing:-

Artwork given the actual size of coponets conductor orientation routing & spacing.

3. Negative Preparation:-

For the perparation of negative the photographic lith film is cut to the

size of artwork. This film is then bathed through fixed which is the sodium trisulphate

solution. This film is then worked with water & is then dried.

4. Pattern Transfer:-

The copper clad sheet is cleaned with steel wool & wash with water &

then dry the sheet. Then the copper clad sheet is coated with the photoresist material. The

coated sheet is then exposed to UN rays through the film the master. Then we develop the

copper clad sheet in photodeveloper for cascaded development.

5. Etching

The PCB is then kept in ferric chloride solution for removal of unwanted

copper.

6. Washing

We wash the PCB with simple water & dry it.

7. Drilling

The holes are then drilled in PCB for comonent insertion.

SOLDERING

START PROCESS

LIST OF COMPONENTS

SEMICONDUCTOR DEVICE

1. IC1 LM 339 quad comparator

2. IC2, IC3, IC8 NE-555 Timer

3. IC4 74 LS92 (Divide by 12 counter)

APPLY SOLDER PASTE

PLACE COMPONENT

CURESOLDER PASTE

REFLOW SOLDER

CLEAN THE TEST CHIP

4. IC5 (N4-N3) 74 LS00quad 21/P NAND gate

5. IC6 (N4-N6) 74LS08 quad 21/P AMD gate

6. IC7 (N7-N10-N17)

7. IC9 (N11-N16) 74LS04 hex inverter

8. IC10 7805+5 volt regulator

9. D1 TO D3 IN4148 Switching Diode

10.D4-D8 IN4007 rectifier diode

11.T1, T2 BC557 PNP transistor

12.LED1, LED7, LED8 3mm red LED

PASSIV COMPONENTS

RESISTOR:-

1. R1 47KO

2. R2 22KO

4. R3, R5, R7

5. R8, R16 10KO

6. R4 100KO

7. R9,R10,R17 3.3KO

8. R11,R12,R13,R14

9. R15,R18,R19 470KO

10. R20,R21 1KO

11. VR1 4.7KO Preset

12. VR2 220 KO Preset

13. VR3, VR4 470KO Preset

CAPACITORS:-

1. C1 .47 μf Ceramic Disc

2. C2, C3, C6, C7, C12 .01 μf Ceramic Disc

3. C14, C11, C13 100 μf, 25 V Electrolytic

4. C8 10 μf, 25v Electroytic

5. C9 220 μf, 25 Electrolytic

6. C14 1000 μf, 25 V Electrolytic

IC DETAILS

PIN OUT DIAGRAM

VCC I1P O1P I1P O1P I1P 8O1P

I1P OIP I1P O1P I1P O1P GNO

O 1

INPUT O OUTPUT

IC SPECIFICATION

IC 74LS04

14 7404

7404 is used as NOT gate. It consist of 6 not gate 1 pin is for ground & other is

for Vcc. Since it belongs to TTL family, its operating voltage is 5V.

LM339 Quad Comparator

It is a comparatorthe voltage applied at its input terminal with reference voltage

applied.

IC 74 LS04

7404 is used as NOT gate. It consist of 6 not gate 1 pin is ground & other is for

Vcc. Since it belongs TTL family, its operating voltage is 5V.

PINOUT DIAGRAM

I1P I1P

VCC O1P 8 O1P

14

I1P O1P I1P O1P 7 GND

0 O 1

I1P O O1P

1

SYMBOL

A NC O.O O.1 GND 0.2 O.3

B NC NC NC VCC RO1 RO2

CLOCK QC QB QA A B C D R FNORMAL L L L L L L H H H1ST L L H H L L H L H2ND L H L L L H H L H

7400

14 7492

3RD Default L H H H H H L H H3RD L H H H H L H L H4TH H L L L L H0 H0 LO L#

NOTE * LOW/HIGH FOR 50Δ # : L/H AFTER 50Δ

TRUTH TABLE FOR 74LS92

74LS92: -

It is a TTL IC operated at 5V. It is a divide by 12 counter

74LS00: -

it is a quad 2 input NAND gate

Input Output

0 0 1

0 1 1

1 0 1

1 1 0

74ls08: -

It is a quad 2 input TT gate

Input Output

0 0 0

0 1 1

1 0 0

1 1 1

NE555 Timer

Pins No. Description

1. Ground

2. Trigger Input

3. O/P

4. Reset

5. Control Voltage

6. Threshold

7. Discharge

8. +Vcc

7805+5 Volt Regulator

1. Input

2. Common

3. Output

SEMICONDUCTOR DIODES: -

IN4148: -

It is switching diode used to provide trigger input to monostable multivibrator

when forward biased.

IN4007: -

Rectified Diode

TRANSISTOR

BC557: -

It is a PNP transistor.

LED: -

It is a light emitting diode.

RAW MATERIAL

1. Ribbon Cable

2. Signal & Multistand Wires

3. Solder Wire

4. Flux

5. Copper Clad Sheet

6. Thinner

7. Steel Wool

8. Ferriechloride

INSTRUMENTS USED

1. Tester

2. Screw Drive

3. Digital Multimeter

4. Soldering Iron

5. Bread Board

6. Blade

7. Plier

8. Cutter

9. Twisser

10. Magnifying Lamp

11. Drilling Mechanic

12. Heting Element

13. Varies

FRONT PANEL CONTROL OF CABINET:-

1.2s 2M 50s Qc QB Q o

TIMER LED s CODE COUNTER

POWER LED

POWER SWITCH PUSH BUTTON RELAY LED

FRONT PANEL CONTROL

1. Power LED & Power Switch: -

Power to switch on or off the supply to ckt. Power LED

indicates that power supply is reaching at input of ckt.

2. Timer LED’s:-

These LED’s are timer LED and glows as per the time period

set by multicuibrator IC’s

3. Counter Code:-

These LED’s represents the 7492IC when trigger signal is

given to ckt.

4. Trigger:-

It is a push button used to produce input signal in the case mic

is not worked.

5. Device ON LED:-

It is glows when relay is activated

FAULT FINDING & TESTING:-

Fr easy adjustment & testing built in LED indicators are provided at various points of ckt.

Trouble shooting proodure

1. 1st check the ltage atpins 2, 4, 3, of IC 10 which should be in range of 4. V to 5.2 V. if it

is not so than check mains supply presence at primary winding of X & 12V reaching

pins 1 & 2 of IC 10 (7805).

2. Remove IC3 from socket temporary.

3. Touch the microphone gently with finger & observe the LED is lit for approximately

1.2 seconds. Not adjust VR2 to get that timing. If no change occurs than adjust preset

VR, starting from a lower value using multimeter check whether colloctor voltage or

transistor changes. After that if IC2 doesn’t respond then IC2 may be faulty.

4. To check the operation of counter IC4, mementory shot pin 1 of gate N1 To ground

using twisser.

SAFETY PRECAUTIONS

1. Never use the less than a V or more than 12 V power supply.

2. The soldering should be proper.

3. Variables resister should be proper.

4. Prevent overheating of any IC.

5. Grounding should be proper.

6. Layout should be correct.

7. Mounting of compo should be proper.