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1. PROJECT REPORT
TITLE : PULSE GENERATOR
WORK AREA : PA-C/T-II/IFF
HELPING MEMBERS : MR. JYOTI PRAKASH
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1

2. 2
1. INTER-CHANGEBILITY PROBLEM OF PCBS/MODULES
2. NON AVALABILITY OF TEST JIG FOR IFF MODE-S TESTING
3. ALTERNATE TEST SET-UP FOR TX PULSE FREQ MEASUREMENT
4. NO INDIVIDUAL MAINS SWITCH FOR EACH TABLE
5. WORK AREA BECOMES DUSTY QUITE OFTEN.
6. NO PROPER SITTING ARRANGEMENT.
7. NO BACK-UP ARRANGEMENT FOR PC.
8. TESTING CYCLE TIME FOR IFF-FLYCATCHER.
9. NON-AVAILABILITY OF PRIMARY TRIGGER FOR IFF-SPAGU
10. DISTURBANCES DUE TO OPEN HANGER.
PROBLEMS

3. 3
PROBLEMS contd…..
11. MAINTENANCE OF LIGHTING IN TESTING HANGER.
12. LACK OF MAINTENACE AND CLEANING OF WORK AREA
13. ELECTRICAL WIRING , SUPPLY SOCKETS AND SWITCHES ARE IN BAD
CONDITION ON WORKING TABLE.S
14. IFF INTEGRATION PROBLEMS AT SITE.
15. LOT OF NOISE DISTURBANCE IN WORK AREA
16. FREQUENT FAILURE OF 400 W TPA.
17. NO PROPER STORAGE OF UNUSED INSTRUMENTS.
18. NO CENTRALISED STORAGE OF ACCESSORIES.
19. ADJUSTMENT RF POWER AT SYSTEM LEVEL

4. 4
SELECTION OF THEME
THROUGH BRAIN STORMING
MEMBER DECIDED TO SELECT A
PRODUCT RELATED PROBLEM

5. 5
a. Interchangeability problem of PCB’s and modules.
b. Frequent failure problem of 400 W TPA
c. Testing cycle time of IFF Flycatcher.
d. IFF integration problem at site.
e. Non availability of test jig for IFF MODE-S TESTING
f. Adjustment of RF Power at system level

6. 6
1. MODE-S DRAWER WAS ADDED IN THE EXISTING
IFF MK-X EQUIPMENT OF IFF - REPORTER.
2. MODE-S IS DEVELOPED FOR INDIAN DEFENCE
SEVICES FOR SECURE MODE OF IDENTIFICATION.
IT IS A SELECTIVE TYPE INTERROGATION USED TO
MAINTAIN SECRECY OF AIR CRAFT’S CODE.
3. ENCRYPTION (POLY & KEY) IS USED WHILE
INTERROGATING IN MODE-S. THE REPLY
CONSISTS OF AIR CRAFT CODE (POLY+KEY)
OF 8.5 µS FRAME
INTRODUCTION

7. 7
MODE-S
DRAWER CRO
MODE – S DRAWER TESTING
(VARIOUS ALTERNATIVES)
AC MAINS
SUGGESTION: SYSTEM LEVEL INTEGRATION
THE MODE-S DRAWER CAN BE TESTED AS A TOTAL
SYSTEM INTERCONNECTING WITH IFF INT-DEC
MK-X
DRAWER
AC MAINS
OUT PUT

8. 8

9. MODE – S DRAWER TESTING
(VARIOUS ALTERNATIVES)
LIMITATIONS:
(i) MORE TIME REQUIRED,
(ii) DIFFICULTY IN TROUBLE SHOOTING
PCBS & MODULES
(iii) HOLDING ONE EQUIPMENT(INT-DEC)
(iv) DIFFICULTY IN TROUBLE SHOOTING
ON REAR PANEL SIDE MODULES
MOTHER BOARD & POWER SUPPLIES.
9

10. 10

11. 11
PULSE
GEN
MODE ‘S’
UNIT
UNDER TEST
CRO
SUGGESTION : TEST SET-UP FOR TESTING OF
MODE-S DRAWER INDEPENDENTLY
AC MAINS
115 V, 400 HZ
MODE-S CHALLENGE
TX PULSES O/P
SIM O/P
MODE-S ZRP O/P
VIDEO O/P
PRE-TRIG
POWER
SUPPLY
MODE-S ON
RAW VIDEO
LIMITATIONS: 1) SET-UP IS BULKY
2) HAVING MORE LOOSE CONNECTIONS
3) REQUIRES MORE TEST EQUIPMENTS
4) INADEQUACY TO CHECK ALL
PARAMETERS

12. ACTIVITIES:
Design of MODE-S test jig for PCBs & drawer testing
which should incorporate the following features:-
1 Adjustable PRT , Pulse width. Pulse generator for
generation of pre trigger signal.
2. +5 volt power supply for Challenge command and for
trouble shooting purposes
3. Checking the interfacing of MODE-S & MK-X (Int-
Dec) units.
4. Monitoring of interface signals.
12

13. 13
PULSE GENERATOR
CIRCUIT Diagram
54 LS 123 / A
15 KΩ
100 K Ohms
PRT Adj
56 KΩ
10 K
PW Adj 100 PF
47 KPF
1
2
3
14
15
13
4
9
10
11
6
7
5
12
54 LS123 / B
VCC
VCC
GND
54 LS 37
BUFFER
1,2 6
PW : 0.8 µs, PRT : 2.2 ms
O / P
Amp .3.5 V
3
5
7

14. 14
MODE ‘S’ TEST JIG
EXT O/P + 5 V
PULSE
GEN CKT
Specs:
Pw 0.5µs,
Prt : 2,2mS,
Amp: .3.5V
1
2
3
2
4
1
7
8
MODE ‘S’ INTERFACE
MODE’S’ MATCH VIDEO
MODE’S’ TX PULSES
PRE TRIGGER
MODE S ZRP
CHALLENGE CONTROL
AC MAINS
5 V, 5A
POWER SUPPLY
9
GND
+ 5 V
GND
GND
+ 5V
GND
+ 5V
+ 5V
+ 5V
S 1
S 2
S 2
PRE TRIGGER
+ 5 V
+ 5 V

15. 15

16. TEST SET-UP
16
MODE-S
UNIT TEST - JIG
CRO
CONNECTOR
INTERFACE CABLE

17. 17
TEST PROCEDURE
1. CONNECT THE TEST JIG AS PER THE SET UP.
2. CHECK THE +5V OUTPUT
3. SWITCH ON S-1 & OBSERVE THE ‘PRE TRIGGER
OUTPUT’ ON CRO.
4. SWITCH ON S-2 & OBSERVE THE ‘MODE PULSES
OUTPUT’ ON CRO.
5. SWITCH ON SIM ON MODE-S DRAWER & OBSERVE THE
‘MODE-S MATCH LED ON’.
6. OBSERVE ‘MODE-S VIDEO’ ON CRO FOR 70 + 5 µS.

18. 18

19. 19
1. AVOID THE USE OF PULSE GENERATOR EXCLUSIVELY FOR
MODE-S TESTING.( 1 lac approx)
2. AVAILABILITY OF + 5 V DEDICATED POWER SUPPLY FOR
TROUBLE SHOOTING.
3. USE OF AVAILABLE COMPONENTS.
4. AVOIDING MK-X SYSTEM FOR TESTING.
5. MAN-HOUR TESTING REDUCED FROM 48 Hrs TO 40 Hrs MAN
HOURS SAVED 8Hrs / UNIT (15 x 8 = 120 x 1023 = Rs. 122760/-)
6. MAN-HOUR TESTING REDUCED FROM 24 HrsTO 20 Hrs. MAN
HOURS SAVED 4Hrs / SPARES / SET(5x4=20x1023=Rs. 2460/-
7. EASY TO CARRY TO SITES FOR REPAIR JOB AND SAVINGS
OF TA/DA ( Rs. 1 lac approx)
8. TOTAL SAVINGS OF Rs : 325220/-
BENEFITS (TANGIBLE)

20. 20
1. NEAT TEST SET-UP
2. EASE IN TESTING/TROUBLE SHOOTING AT
BENCH LEVEL.
3. COMPLETE TESTING OF ALL PARAMETERS
AT BENCH LEVEL.
4. STAND ALONE TESTING WITHOUT HOLDING
IFF EQUIPMENT.
5. PARALLEL TESTING ARE POSSIBILE.
6. CLEARANCE OF SPARES AT BENCH LEVEL.
BENEFITS (INTANGIBLE)