Vivitar 283 User manual

• Vivitar.
Service Manual
Automatic Electronic Flash
Model 283
Publication No. 3746059 I December 1976
Revision A June 1978
Revision B November 1980

•
This manual consists of the following pages:
Page Revision Date
Front Cover B 11/80
Page A B 11/80
i, ii, iii, iv
B 11/80
1 -
44
B 11/80
•
Page A Vivitar 37460598 (11/80)

•
•
•
HOW TO USE THIS PUBLICATION
HOW TO FIND PART ORDER NUMBERS
Automatic Electronic Flash
Model 283
Parts are illustrated on exploded view drawings where each part is identified by a reference number or designator. These
reference numbers appear in sequence in the parts lists where they are cross-referenced to the part numbers and descriptions.
When a part
is not available separately it will be so indicated by a footnote and can be obtained by ordering the assembly
containing
it. The part number of that assembly may be shown immediately to the right on the same line in an "Included
in Assembly" column or at the end of the parts list(s).
CAUTION
This publication is intended for use by persons having skills and equipment
needed
to service the subject product(s) safely and correctly. Users are
cautioned that special tools and/or test equipment may be required for
proper disassembly, reassembly, alignment, or ajustment or damage to the
product may result.
WARNING
The product herein described is electrically operated. Its servicing will re·
quire extreme caution. Improper handling could result in serious
or fatal
personal
injury and damage to the product.
Notice:
Information contained herein is subject to change without notice.
HOW TO ORDER PARTS
Please furnish the model number and serial number of the product for which parts are being ordered. For each part
requested, please supply part number, description, and required quantity. Mail or phone parts orders to:
U.S.A.
Vivitar Corporation
Central Parts Service
2700 Pennsylvania Avenue
Santa Monica,
CA 90406
Tele: [phone]
or [phone]
CANADA
Vivitar Canada Ltd/Ltee
5211 Creekbank Road
Mississauga, Ontario, L4W1 R3
Canada
Tele: [phone]
BELGIUM
Vivitar Belgium, S.A.
29,
Passage International
Boite
35
1000 Brussels, Belgium
Tele: 2 2191277
or 2 2191383
FRANCE
Vivitar Franee, S.A.
41-43 Rue de Villeneuve
Silic 197
94563 Rungis, France
Tele: 687-3235
WEST GERMANY
Vivitar Photo·Elekronik, Gmbh
Vivitar Strasse 7-9
6238 Hofheim TIS
West Germany
Tele:
06192/7040
HOLLAND
Vivitar B.V.
Postbus 168
NL3640 AD
Mijdrecht, Holland
"f.ele: (02979) 2001
UNITED KINGDOM
Vivitar U.K. Ltd
Vivitar House
Ashville Trading Estate
Nuffield Way
Abingdon,
Oxon LX14 1 RP
United Kingdom
Tele: (0235)
26600
ASIA, OCEANIA, AFRICA,
MIDDLE EAST, CARIBBEAN,
LATIN AMERICA
Vivitar Japan Ltd.
Marusho Bldg., 6th Floor
12 Yotsua 3-Chome
Shinjuku-Ku
Tokyo 100, Japan
Tele: 357-6021
Vivltar 37460598 (11/80)

Au tomatic Ele ct ro ni c F lash
Model 283
TAB LE OF CONTENTS
S ection
1.0 I
NTRODUCTION
1.1 SCOPE OF MA NU AL ............. ...... . . . . .............. .
1.2
GENERAL SPECIF ICAT IONS ........ ... . . .............. . . .. .
1.3
GUIDE NUMBERS ................ .. . . .................. .
2.0 PR INCIPLES OF OPERA TI ON - CIRCU IT DESCRIPTION .... . . . . .
2.1 GENERAL ............................................ .
2.2 POWER SOURCE
.. . .................................... .
2.3
OSCILLATOR CIRCUIT ........... . ...................... .
2.4
BATTERY SAV ER CIRCUIT ............................ . .. .
2.5
RECTIFIER AND POWER STORAGE CIRCUIT ............ . . . . .. .
2.6
TR IGGER CIRCU IT .............. . . . .............. ... . . . .
2.7
AUTO CIRCU IT AN D BOUNCE COMPENSATOR CI RC UI T ..... . . ... .
2.8 QUENCH CI
RCUIT .................. . . . ................. .
2.9
SUFFICIENT LIGHT INDICATOR CIRCUIT . . ................... .
2.10
READY LIGHT NEON INDICATOR CIRCUIT ................... .
2.11
DIAL LIGHT NEON IND I CATOR CIRCUIT ..................... .
3.0 DISA SSE M BLY A ND REASSEMBLY .. .... . .. . .......... . . . . . . . .
3.1 GENERAL ............................................ .
3.2
DISASSEMBLY ..................... . ................. . .
3.3
FLASHTUBE AN D REFLECTOR ASSEMBLY ................. . .. .
3.3
.1 Positioning ..................... . . . ................. . .. .
3.3.2 Polari
ty ......................... . .. . ................. .
3.3.3 Soldering
...................... . . .... ................. .
3.4 REMOTE SENSOR DISASSEMBLY
...... . .................... .
3.5
REASSEMBLY ......................................... .
3.6
CLEANING ........................................... .
3.6.1 Mechanical and Electronic Components
......................... .
3.6.2 Reflector Assembly and Ftashtube Lens
......................... .
3.7
ELECTRONIC COMPONENT REMOVAL .. . . . . ............... . . .
4.0 CHECKOUT AND TROUBLES H OOTING ......... .. ......... .. . . .
4.1 GENERAL .. . . . .................. .. ... . ........ . ... . .. .
4.2
OPERATIONAL CH ECKOUT ........... . . . ................ . .
4.2.1
Too lsand Test E quipment .................................. .
4.2.2 Main Storage Capacitor Forming
........ . . . ................... .
4.2.3 External Checkout
................. . . . ................. . . .
4.2.4 External Check and
Adjustment of Main Capacitor Voltage ............ .
4.2.5 Main Capacitor Leakage Check
.......... . . . .................. .
4.2.6 Neon
Indicator ......................................... .
4.2.7 Recycle Time
....................................... ... .
4.2.8
Full Power Light Output Check ....... . . . . . .............. .... .
4.2.9 Calibrating The
Auto Ci rcuit ........ .. . . . . .. . ....... . . .... . . .
4.3
ELEC TRO NIC CO M PO NENTS AND VA LU ES .. ... .. .......... . . . .
4.3.1 Measurement Data
........................ . .............. .
4.3.2 Transistors
.. . ......................................... .
4.3.3 Transformers
.......................................... .
4.3.4 Silicon Controlled Rectifiers
............................... . .
4.3.5 Voltage Readings
in Circuit ................................. .
4.4
TROUBLESHOO T ING .................................... .
5.0 ILLUSTRATED PARTS LI ST ..... . . .. . . .. . .............. . . . .. .
ii
Vivitar 37 4 60 598 (11 /80)
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P age
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3
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Figure
2-1
2-2
3-1
3-2
3-3
3-4
3-5
3-6
3-7
3-8
3-9
3-10
3-11
3- 12
3-13
3-14
3-15
• 3-16
3-17
3-18
3-19
3-20
3-21
3-22
3
-2 3
3-24
4-1
4-2
4-3
4-4
5-1
5-2
5-3
5-4
5-5
5-6
5-7
•
Automatic Electronic Flash
Model 283
LIST OF ILLUSTRATIONS
Title Page
Block Diagram Princliples Of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Schematic Diagram
Cover
Plate Removal ........................................ .
Reflector Case Disassembly .................................... .
Reflector And Body Case Separation ............ . ........ . ........ .
Body Case Disassembly ...................................... .
Discharging
The Main Capacitor .............. . ................. .
Positioning Body Case Halves ................................... .
Discharging
Capacitor C11 ..................................... .
Sensor Receptacle Removal .. . ......... . ....................... .
Battery Case Removal ..................................... . .. .
PC Board C Removal
......................... . .... . ......... .
Further Disassembly ......................................... .
Reflector Removal .................. . ....................... .
Flashtube Removal
F
lashtube Polarity
Screw Removal ............. . .............................. .
Removing The Plastic Retainer ........ . ......................... .
Desoldering
04 ............................................ .
Reassembling
Body Case LA ................................... .
Positioning PC-1
Receptacle .................................... .
Installing PC
Boards Band C ............ . ....................... .
Battery Case Installation ...................................... .
Shoe Attaching Plate Position
Cover Plate, Exposure Dial Reassembly ............................ .
F-Stop Plate Exposure Dial Reassembly ............................ .
Adjustment Points, Auto And Battery Saver Circuits ....... . ........... .
Checking Main Capacitor Voltage ................................ .
Main
Capacitor Leakage Test ................................... .
Positive
Test Lead Locations While Testing Voltages .................... .
Exploded View - Body ...................................... .
Printed Circuit Board A Assembly (Trigger)
Printed Circuit Board C Assembly (Auto) .................. . ........ .
Printed Circuit Board B Assembly (Power Supply) ..................... .
Spare Sensor .............................................. .
Schematic Diagram ......................................... .
Wiring Diagram
............................................ .
4
7
8
8
8
9
9
10
10
11
11
11
12
12
12
13
13
13
13
14
14
15
15
16
16
18
18
19
25
32
34
36
38
40
41
42
Vivitar 37460598 (11/80) iii

Au tomat ic Electro ni c Fl ash
Model 2 83
Table
1-1
1-2
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
4-11
4-12
4-13
LI ST OF T AB LES
Title
Guide Numbers
Automatic Oper a tion F-Stop Settings ..................... _ ....... .
Recycle
Time ........................... _ ................. .
Auto Circuit Calibration Specifications ............................ .
01 Resistance Readings ...... .. ...... . ...... ... ...... ... ..... .
01 Voltage Readings ............................... _ ........ .
02 Resistance Readings ............................ _ ....... _ ..
02 Vo ltage Readings .......... .... ...... . ...... . .......... . . .
T1 Resistance Readings
T2 Resistance Readings ....................................... .
T3 Resistance Readings ........... ... ....... .. ..... .... ....... .
SCR 1 Voltage Readings
...................................... .
SCR2 Resistance Readings ............ ..... .... ... ...... ... .... .
SCR3 Resistance Readings ..... ...... .. ... .... ... .............. .
Voltage Readings in
Circuit ..................... . .............. .
iv Vivitar 37460598 (11/80)
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Page
2
2
19
20
21
21
22
22
22
23
23
23
24
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24 •
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SECTION 1
INTRODUCTION
1.1 SCO PE OF MA NU AL
Automatic Electronic Flash
Model 283
This document is the Service Manual for the Vivitar Electronic Flash Unit Model 283, sold under Vivitar stock
number 0233952 and
further identified by Vivitar Top Assembly part number 3900277. This manual provides
information on principles
of operation, operational checkout, troubleshooting, disassembly and reassembly, repair,
component replacement, and recommended tools and test equipment. A parts list, exploded view drawings,
schematic diagram,
PC board layout and wiring view drawings are also provided.
Please note that illustrations and parts li sts are based on production data at time of publication, and that details
may vary
with producti on changes .
1.2 GENERAL SP EC IFIC ATIONS
Automatic Operating Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . PURPLE Mode: 2 ft. to 11 ft. (0.6m \O 3.3m)
BLUE Mode: 2 ft. to 15 ft. (0.6m to 4.5m)
RED Mode: 3 ft.
to 30 ft. (0.9m to 9m)
YELLOW Mode: 3 ft. to 43 ft . (0.9m to 13m)
Automatic Sensor Measuring Angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
degrees
BCPS (Beam Candle Power Seconds) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,900 (Manual)
Recycle Time
(fully charged or fresh batteries) . . . . . . . . AC: 7 seconds (Manual). 0.5 to.., ;aconds (Automatic)
DC: 5
seconds (Manual) with NiCad batteries, 0.5 to 5 seconds (Automatic) with NiCad batteries
9
seconds (Manual) with alkaline batteries, 0.5 to 9 seconds (Automatic) with alkaline batteries
Flash Duration (approximate) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1/1000 second (Manual)
Color Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5500
degrees Kelvin
Angle(s)
of Illumination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 degrees horizontal, 45 degrees vertical
Operating Position(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vertical,
with variable tilt reflector assembly
Power Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AC: 105·1 25V w ith Vivitar SB- 4 AC Adapter
DC:
Fo ur AA alka li ne 1.5V batteries or
Vivitar Interchangeable NiCad Ba tt ery Pack (NC-3)
Flashes per Set of AA alkaline batteries . . . . . . . . . . . . . . . . . . . . . . . . . . 75 (Manual). 75- 80 0 (Automatic)*
Flashes per 15-minute charge with Ni C ad Battery Pack . . . . . . . . . . . . . . . . 50 (Manual). 50-800 (Automatic)•
Camera /Electronic Flash Synchronization Connection(s) ......... PC sync cord, hot shoe, or sensor holder cord
*Number of flashes in the Automatic Mode depends on Flash to Subject Distance, room reflectivity, and Auto f-stop
setting
used .
Vivitar 37 4 60596 (11/80)

Automatic Electronic Flash
Model
283
1.3 GUIDE NUMBERS
MAN UAL OPERATION
Gu ide Numbers (ASA-Feet}
ASA Film
Speed
25
Flash Guide No.
60
Guide Numbers (DIN-Meter)
DIN Film Speed 15
Flash Guide No. 18
64
96
19
29
Table 1-1. Guide Numbers
80 100 125 160 200
10 8 120 135 150 170
20
21
22
23 24
32 36
40 45
51
Table 1-2. Automatic Operation f-Stop Settings
AUTOMATIC OPERATION
Auto f-Stop settings to the closest half-stop:
Film
Speed : ASA 25 64*
80* 100* 125* 160* 200*
DIN
15 19 20 21 22 23 24
YELLOW Mode 1.4 2.4 2.4 2.8 3.5 3.5 4
RED Mode 2 3.5 3.5 4 4.7 4.7 5.6
BLUE Mode 4 6.7 6.7 8 9.5 9.5
11
PURPLE Mode 5.6 9.5 9.5
11 14 14 16
400 800
240 340
27
30
72 100
400 800
27 30
5.6 8
8
11
16 22
22 32
*These ASA film
speeds differ by only 1/3 of an f -s top. The resulting change in exposure is so slight that a
chang e in the Auto f-stop may not be indicated.
2 Vi v itar 374 605 98 (11 /80)
•
•

2.1
•
SECTION 2
Automatic Electronic Flash
Model
283
PRINCIPLES OF OPERATION - CIRCUIT DESCRIPTION
GENERAL
The Vivitar Model 283 Auto Electronic Flash Unit provides a source of variable-duration, high-intensity
light, keyed
to preset camera f-stops and automatically compensating for distance by means of auto control
circuitry. In any of the four automatic modes of operation, flash duration and intensity are automatically
controlled. The manual mode furnishes constant, maximum
light output.
The major circuits of the unit are oscillator, rectifier and power storage, flash trigger, quench, light sensing,
bounce compensator (BCC), and auto
control. There is a neon indicator circuit for the ready light, the cal·
culator dial light, and the sufficient
light indicator light. The Model 283 operates from a battery or AC
power source. See Figures 2·1 and 2·2.
POWER SUPPLY ANO STORAGE
r--------------- -,
I
I
L_
Oscillator
01 02 T1
Battery
Saver
SCR1 R6
Rectification
2
Storage
03 04 Cl
I
I
I
I
I
I
I
I
I
I
-----------~-- -~
I
I
I
I
I
I
0
BCC
C15 C16
s voe 120 vAc
Trigger
T2
Auto
Control
R26
03 012 SCR3
Open Flash
Button
Hot
Shoe
Quench
OT1 SCR?
light
Sensor
Q4
PC Cor d
Figure 2-1. Block Diagram, Principles of Operation
Vivitar 37460599 (11/80) J

Automatic .Electronic Flash
Model
283
<;~.~~~1:,'llf
..
C2
- +
6YDC
Ot
"
r -· -,
lil il• t-<>--O- >-
Sl 0 ~'--------
---.,
,.. -,
r- -- --o •
I t~o :
IL '
I '200VOC
I t
,'DC
03 04 J ~
-.-, - ... ._ ..--.- - i-. 4-J
. 06
A12 06A
l
~ sz er n
Indicator
R10 A ll 05
:1 · tl~ " ~.__._ ~:'u ~
C9 I
:.Ct, r
r- - - ..J - - J - - • , l
c• •-
Lt- +-"'"'._' -i- i::..
I
I
I
I
I
S B- 4
AC Adapttr
I I
L- --r-1 ----!
...
2.2
I I
I
I I
~~J
",
' 4
HOT SHQ[ '') I
1 20 YAC I
/ ~ ~ ~ " __ ____ _j
...
• 010 . 010A and R16 not installed on product i ons after 6/ 25 /7 7
Figure 2-2. Schematic Diagram
POWER SOURCE
The Model 283 is designed to operate with either of the following: 1 - four AA 1.5V Alkaline batteries,
2 - Vivitar NC-3
battery pack, 3 - VivitarSB-4AC adapter, or 4 - Vivitar HVP-1 high voltage battery pack.
2.3 OSCILLATOR CIRCUIT
The basic oscillator circuit consists of a transistor, transformer, and power source. A battery -saving circuit
electronically
controls power demand on the battery.
The major components of the oscillator circuit are the transistors 01 and 02, and the oscillator transformer
Tl.
Th e transistor 01, in conjunction with 02, acts as an electronic switch that causes the battery power to pul-
sate. The pulsating DC, while passing through the primary of Tl, induces a higher voltage in the secondary
winding of the transformer. The transformer output current is rectified and used to charge the main capac-
itor Cl.
2.4 BATTERY SAVER CIRCUIT
The key component of the battery saver circuit is SCR1 which switches off the oscillator circuit when the
main capacitor Cl potential reaches the preset voltage. When the charge in the main capacitor drops below
the set voltage, SCR1 deactivates and the oscillator switches back on.
The potential of the main capacitor Cl and the gate voltage of SCR1 are set by adjusting R6. This variable
resistor
is part of the voltage divider chain that also includes R5, R7, R8, and R9 and is in parallel with
the capacitor C3. Actually, the voltage of the main capacitor is controlled by that of C3, the potenti al of
which can be
set via R6. Whenever C3 - and simultaneously Cl -reach the preset potential, the SCR
switches
on. That is, SCR1 exhibits a low resistance which effectively places the base of 01 at the same po -
tential as its
emitter. Th is removes the forward bias on 01 and thereby shuts off oscillation and stops drain
on the battery.
4 Vivitar 37460 5 98 (11/ 80)
•

•
--
2.5
Automatic Electronic Flash
Model 283
When 01 stops functioning, C3 begins to discharge via R4, T1 and D2, lowering the positive potential on
th e anode of SCR 1. When this potential drops to approximately 1.2 volts, the SCR switches off, forward
bias
is reestablished, and 01 oscillates once more .
RECTIFIER AND POWER STORAGE CIRCUIT
The diodes D3 and D4 rectify the voltage produced by the oscillator and transformer T1, and the power
is stored in the main capacitor C1.
The pulsating DC produced by the oscillator is stepped up by T1. The diodes D3 and D4 chop the nega-
tive excursions
off the resultant AC, that is, these two power rectifiers allow current flow in one direction
only. The main capacitor C1 charges up to the preset voltage. When an AC power source is used to operate
the unit, such as the Vivitar SB-4 cord, 200VDC is applied to this circuit at the junction between D3 and
D4. D3 blocks T1 from this high voltage, while D4, in conjunction with C1, raises the potential to approx -
imately
320V.
2.6 TRIGGER CIRCUIT
When C1 is charged, the trigger capacitor C7 is also charged to the same potential via R 19 and R12. When
the synch or open flash contacts are closed, via the open flash button, camera shutter, or PC cord, C7 is
connected via D5 across the primary of T2. The discharge of C7 produces a momentary high voltage pulse
in
the secondary of T2, which ionizes the gas in the flashtube, providing a path for C1 to discharge across
the flashtube. C6 and R 13 increase the trigger efficiency of this circuit. Before the xenon tube can fully
ionize and
permit C1 to discharge through it, SCR2 must be gated in the following manner.
The trigger pulse applied from T2 secondary to the flashtube ionizes the gas in the xenon tube FT1. This
causes
the 300V potential of C1 to appear at the anode of SCR2 and the anode of DB. Current flows
through DB, C11, L2, C13, R17 and R1 B, and the voltage pulse appearing at the junction of R17 and R1B
is applied to the gate of SCR2. This causes SCR2 to conduct, and the main capacitor now discharges across
FT1,
through SCR2 anode to cathode, and back to C1 lower plate. In manual mode, C1 fully discharges
and SCR2 reverts
to "open" circuit condition upon deionization of FT1. For auto function, see Section 2.B,
Quench Circuit.
2.7 AUTO CIRCUIT AND BOUNCE COMPENSATOR CIRCUIT (BCC)
2.8
The light from the flash, reflected by the subject, strikes the photo-transistor 04, causing a current change
(increase)
through R20, this results in a voltage change across R20 and R21, and the base of 03 becomes
negative.
Capacitor C16 integrates the voltage across R20, which upon reaching the required potential, drives
03 into forward bias. Collector current now passes through R23 and R24. The voltage developed at the
junction of R23 and R24 is applied to the gate of SCR3, which, on reaching +0 .6V, switches SCR3 on.
When this occurs, C19 discharges through SCR3, which acts like a low resistance, through the primary
winding
of T3, back to the opposite plate of the capacitor. T3 will now have a high voltage induced into its
secondary winding providing
the trigger pulse necessary to fire OT1.
The bounce compensator circuit is automatically switched on when the unit is set at any of the three bounce
angle positions. It increases the light output to compensate for light loss due to reflection by approximately
one-half
f/stop. This is accomplished by C15 and C16 being connected in parallel, thereby increasing the
time constant of the auto circuit.
QUENCH CIRCUIT
When the quench tube OT1 fires, capacitor C11 discharges through it. With FT1 firing, SCR2 is also con-
ducting, C11 discharge
current passes through SCR2 on its return to C11 left hand plate. This current flows
through SCR2 in the opposite direction of that coming through FT1 and causes SCR2 to switch off ex·
tinguishing the xenon tube FT1.
Vivitar 37460598 (1 1/80) 5

Automatic Electronic Flash
Model 283
2.9 SUFFICIENT LIGHT INDICATOR CIRCUIT
The sufficient light indicator neon lamp DS3 works if sufficient light is received by the sensor to make the
auto circuit function. The firing of OTl, allows ClO to discharge and ionize DS3.
The potential of the neon lamp DS3 is at the same potential as OTl which charges up ClO. This capacitor
cannot discharge, due to 09. Therefore there is no light. When OTl fires, its resistance becomes very low.
Cl 1 can now discharge through it. The voltage at the junction R 19, ClO, and DS3 drops. Cl 1 discharges at
the same time. Consequently current flows through SCR2 and 08; this permits 09 to conduct and ClO
discharges, ionizing DS3.
2.10 READY LIGHT NEON INDICATOR CIRCUIT
The neon indicator circuit DSl consists of resistor RlO and neon lamp DSl. The voltage induced in Tl sec·
ondary drives current through diodes 03 and 04, charging Cl during that portion of each oscillation
when pin 5 of Tl is positive. DSl will illuminate when capacitor Cl has reached a set potentia l (See Section
4.2.6), which is approximately 60% of its energy storage capacity. Resistor R 10 controls the neon current
when the gas in OS1 ionizes.
2.11 DIAL LIGHT NEON INDICATOR CIRCUIT
This neon indicator circuit consists of resistor R 11, neon lamp DS2, and the calculator dial light switch.
DS2 will illuminate when contact is made by manually depressing the dial light button.
6 Vivitar 37460596 (11/80)
•
•

•
3.1
SECTION 3
DISASSEMBLY
AND REASSEMBLY
GENERAL
Automatic Electronic
Flash
Model 283
This section contains procedures for disassembly, cleaning, electronic and mechanical component removal,
and reassembly
of the Vivitar Model 283 Automatic Electronic Flash. Disassemble the unit only to the ex-
tent necessary for operational checkout, troubleshooting, and repair. Complete exploded view, PC layout
wiring diagram, and schematic are provided in Section 5, Figures 5-1 through 5-7.
3.2 DISASSEMBLY
A. Remove battery cover completely by sliding open and pressing past retaining stop. With flash head
tilted
to "O", remove alkaline cartridge battery from compartment. Unplug sensor assembly and
lay aside. Take
off coverplate by heating slightly with soldering iron and lifting off with thin blade.
Pry
off attaching plate with small screwdriver and lay aside. Figure 3-1.
Battery
'· ···· /Cart ridge
-
Figure 3 -1. Coverplate Removal
0
B. Turn reflector case straight up (90 position), remove screws and lift off reflector case UB. Figure 3.2.
WARNING
Do not touch exposed PC board and associated compo -
nents until you have discharged main capacitor C1 and
Capacitor C11. (See Discharge Procedure Page
9, step F.)
Vivitar 37460598 (11/80) 7

Automatic Ele ct ronic Flash
Model
283
Remove
Screw ~
Reflector
/ Ca se UB
R emove ---------
Screw
·~
Figure 3-2. Reflector Case Disassembly
Remove
Screws
C. Lay reflector case UB aside. Lift body case from reflector case UA and position as shown. F ig. 3-3.
R emove
Note
Reflector
Ca se UA
Figure 3-3. Reflector and Body Case Se paration
0. Remove bounce angle detents, and screws from body case. Fig. 3-3.
E.
Lift back body case LB being careful not to touch main capacitor (C1) contact s or wiring on PC boards.
Fig. 3-4. WARNING
Opening the body case exposes the main capacitor C1 which presents a
serious shock hazard even
when the power source is removed. Handle
the unit with extreme caution until capacitor C1 and capacit or C11 have
been fully discharged. (See Step F)
Figure 3-4. Body Case Disas sem bly
8 Vivitar 37 4 60598 (1 1 /80)
•
•

Automatic Electronic Flash
Model 283
F. To expose the terminals of the main capacitor (C1) for discharge, lift out the exposure dial coverplate,
ASA/footage-mode indicator plate, f- stop plate, and expos ur e dial r ef l ecto r assembly. Be extremely
careful not to touch main capacitor termina ls while removing exposure dial plates and reflector
assembl
y. A wire-wound resistor, preferably a vitreous enameled type, is recommended for discharging
the main capacitor. For safest handling, test probes shou ld be soldered to the resistor terminals and
the so ld er contacts insulated. The reflector assembly should remain attached to PC board C by two
wi res. Discharge the capacitor through the resistor for at least 5 seconds.
Cov erp late
Re flector
A sse mbly
/
Figure 3-5. Discharging the Main Capacitor
Discharge
Cl
G. To discharge capacitor C11, position body case halves and reflector case UA as shown. Fig. 3-6.
Reflector Ca se
Figure 3-6. Positioning Body Case Halves
Vivitar 3 7460598 (11 /BO) 9

Automatic Electronic Flash
Model
283
10
W ARN ING
Capacitor C11 on PC Board A presents a serious shoc k hazard
even
after main capacitor C1 has been fully discharged. Be
sure th at capacitor C11 is fully discharged in the same manner
as described in
Step F.
H. Gra
sp th e outs ide of reflector Case UA -being careful not to touch the PC trigger bo ar d A and
associa te d com pone n ts and leads - and position as shown. Fig. 3.7. Lift the bac k edge of refle ct or
case UA, and discharge capacitor C11 through a 100 ohm, 10W resistor at terminal po int s shown.
I. Sl ide PC trigger board A and flashtube reflector assembly and lens out of reflect or case UA. R emo ve
piece of plastic insulation
between PC board and reflector assembl y. Fig. 3.7.
Reflector
Lens
Plastic
Insulati on
D ischarge
Cl1
PC Trigger
/ Board A
Figure 3-7. Di sc harging Ca p aci tor Cl 1
J. D etac h sensor receptacle from body case LB by removing screws. L ay b ody case LB aside. F ig . 3-8.
Sen sor
Rece
pt acle
,.
Vivita r 37 4 60598 ( 11 /80)
Figure 3-8. Sen so r Receptacle Removal
•

•
Automatic Electronic Flash
Model
283
K. Detach battery terminals from battery case, and lift battery case out of body case LA. Fig. 3-9.
L. Remove shoe attaching plate and associated piece of plastic insulation. Fig. 3-9.
Sensor Receptacle
Insulation
Shoe Attaching
Plate ----- - .:::
Figure 3-9. Battery Case Removal
Battery
Case
M. Remove main capacitor C1 by carefully breaking glue band and lifting out of case as shown. Fig. 3-10.
N.
Slide PC board 8 out of grooves. PC board C can now be
lifted out of case.
PC Board B
PC Board C
Figure 3-10. PC Board Band C Removal
0. Detach BCC (bounce compensator circuit) switch by removing two screws. Slide PC-1 receptacle up
and out of compartment. Lay body case LA aside. Fig. 3-11.
P. To further disassemble PC boards and components, desolder leads as required.
BCC Switch
------- PC-1
Receptacle
Remove
Figure 3-11. Further Disassembly
Vivitar 37460598 (11/80)
11

Automatic Electronic Flash
Model 283
3.3 FLASHTUBE
AND REFLECTOR ASSEMBLY
Handle the flashtube and reflector ass embly carefu lly to avoid damaging the el ectrode seals.
A. To remove
on ly the reflector, unsolder the
red, positive lead from the flashtube, and
gently slip the refl ector assembly off the
flasht ube. Fig. 3-1 2.
,.
r
B. To remove the xenon flashtube, unsolder
the 3 lead wires where sho wn. Be careful
not to lose the clear plastic insulating sleeve
on the trigger lead of the fl ashtube .
Po si t ive
Le ad (R ed)
F ig. 3-1 3.
R ef l ecto r ~
J - l.· ·
¥
Bu s hin gs
Figure 3-12. Reflector Removal
· / ~ Trigger Lea d
Insu lation
Figure 3-13. Flashtube Removal
3.3.1 POSITIONING. As
mentioned above, flasht ube removal and r ep l acement should be performed with ex-
treme care to avoid crac king the seals around the meta l el ectrodes. The points wher e the el ectro des e nt er
the glass envel ope are the most sensitive areas of the flasht ub e. Bending the electrodes will cause excessive
strain between the glass and the electrodes. The flash tube sh ou ld be positioned with in 2 soft rubber bushings
(F
ig ure 3-1 2) when mo un te d in t he refl ector assembly with th e l eads exerting minimum pressure on the
el
ectrodes. Any contact between t he flasht ube and othe r compon en ts sh ou ld be avoid ed to prevent dam-
aging
or shorting the elect r odes.
3.3.2 POLAR ITV. The polarity of the flashtube should be checked
when replacing the tube. The positive, high volt age l ead (red)
should be connected to the anode. The negative lead (blue), be
connec t ed to the ca th ode, identified by the pos it ion of the trig-
ger lead
on the outs ide of the gl ass envel ope. F ig . 3 -1 4.
3.3.3 SOLDERING. Ordinary 60 / 40 Rosin Core solder is suitab le
for all flashtube connections on the Model 283. Never use an acid
co re solder for any connection in an electronic circuit.
12 V i vitar 3746059 8 (11 /80 )
Anode(+) Cathode (-)
I J
"*l~Lead
Figure 3-14. Flashtube Polarity
•

3.4
••
• 3.5
REMOTE SENSOR DISASSEMBLY
A. R em ove two screws and l ift off rear cover plate as shown .
Fig. 3-
15 .
B. To rem
ove p hoto diode 04 , pry off plastic retaine r with
thin bla de and desolder leads. Figures 3-16 and 3-17.
Plastic
Retainer
Figure 3-16. Removin~ the Plastic Retainer
REASSEMBLY
Automatic Electronic Flash
Model 283
Remove
"fr
Lift
Figure 3-15. Screw Removal
De s older
Figure 3-17. Des oldering 04
Reassemble the unit by reversing the disassembly procedures and by following the precautions below.
A. R
einsta ll BCC contact plate and spring as shown. Fig. 3-1 8.
Contac t
Plate
Contac t
Point
Con
tac t
S
pri ng
Figure 3-18. Reassembling Body C as e LA
B. Check that the foll owing parts are in place in body case LA :
1. N
eo n lamp lens button
2. ON - OF F swit ch knob
3. Exp os ur e dial lamp bu tton
4. Dial dete nt
Vivitar 37460599 (1 1 /80) 13

Automatic Electronic Flash
Model
283
C.
This Side
Toward
Body Ca se
Fig. 3-19.
Figure 3-19. Positioning PC-1 Receptacle
D. When replacing PC boards B and C, make certain that wires have not been pinched between the
boards and the case before installing sc rews. Fig. 3-20.
Note
Wiring
Figure 3-20. Installing PC Boards B and C
14 Vivitar 37460598 (11/80)
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•