Flashtube An Dre Flector Assemb Ly; Positioning; Polarity; Soldering - Vivitar 283 Service Manual

Automatic Electronic Flash
Model 283
3.3
FLASHTUBE AND REFLECTOR ASSEMBLY
Handle the flashtube and reflector assembly carefully to avoid damaging the electrode seals.
A. To remove on ly the reflector, unsolder the
red, positive lead from the flashtube, and
gently slip the reflector assembly off the
flasht ube. Fig. 3-12.
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r
B. To remove the xenon flashtube, unsolder
the 3 lead wires where show n. Be careful
not to lose the clear p lastic insulating sleeve
on the trigger lead of the f lashtube.
Positive
Lead (Red)
Fig. 3-13.
Reflector ~
J -
l.· ·
¥
Bushings
Figure 3-12. Reflector Removal
· /~Trigger
Lead
Insulation
Figure 3-13. Flashtube Removal
3.3.1 POSITION ING.
As mentioned above, flasht ube removal and replacement should be performed with ex-
treme care t o avoid cracking the seals around the metal e lectrodes. The points where the e lectrodes enter
the glass envelope are the most sensitive areas of t he flashtube. Bending t he electrodes wi ll cause excessive
strain between the glass and the electrodes. The flash tube should be positioned within 2 soft rubber bushings
(Figure 3-12) when mo unted in t he reflector assembly with the leads exerting minim um pressure o n the
e lectrodes. Any contact between t he flashtu be and other components should be avoided to prevent dam-
aging or shorting the electrodes.
3.3.2 POLAR ITV.
The polarity of the flashtube should be checked
when replacing the tube. The positive, high voltage lead (red)
should be connected to the anode. The negative lead (blue), be
connected to the cathode, identified by the position of the trig-
ger lead on the outside of the gl ass envelope. F ig. 3-1 4.
3.3.3 SOLDERING.
Ordinary 60/40 Rosin Core solder is suitable
for all flashtube connections on the Model 283. Never use an acid
core 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
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