1. SETH JAI PARKASH POLYTECHNIC
DAMLA (YAMUNA NAGAR)
SUMMER TRAINING IN
SESSION 2004-07
PREPARED BY:-
SOURAV SINGH : 041515050
DEPARTMENT OF INST. & CONTROL, ENGINEERING
SETH JAI PARKASH POLYTECHNIC DAMLA
(YAMUNA NAGAR)
2. 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
3. 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
4. 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.
5. 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
6. 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.
8. 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.
9. 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 .
10. 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.
11. 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
12. 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
13. 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
14. 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.
15. 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.
16. 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.
20. IC DETAILS
PIN OUT DIAGRAM
VCC I1P O1P I1P O1P I1P 8O1P
I1P OIP I1P O1P I1P O1P GNO
O 1
INPUT O OUTPUT
14 7404
21. IC SPECIFICATION
IC 74LS04
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.
22. 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
7400
14 7492
23. CLOCK QC QB QA A B C D R F
NORMAL L L L L L L H H H
1ST
L L H H L L H L H
2ND
L H L L L H H L H
3RD
Default L H H H H H L H H
3RD
L H H H H L H L H
4TH
H L L L L H0
H0
LO
L#
NOTE * LOW/HIGH FOR 50Δ # : L/H AFTER 50Δ
TRUTH TABLE FOR 74LS92
24. 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
26. 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
28. 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
29. 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
30. 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
31. 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
32. 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
33. 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.
