Voltage Readings In Circuit; Voltage Readings; Scr2 Resistance Readings; Scr3 Resistance Readings - Vivitar 283 Service Manual

Automatic Electronic Flash
Model 283
B. SCR2 CR3GZ·8
Resistance readings between leads. Lead with positive probe is marked with (+). (Table 4-11)
Table 4-11. SCR2 Resistance Readings
OHMS (APPROX.)
LEADS
In Circuit
+G - A
28,000
G -+A
CC*~
+G - K 14
G - +K
14
A -Anode
G - Gate
+A -
K K ·Cathode
A -
+K 25,000
0 -
Insulated
C. SCR3 CR02AM-6
Resistance readings between leads. Lead with positive probe is marked(+). (Table 4-12)
Table 4-12. SCR3 Resistance Readings
LEADS METER
OHMS (APPROX.)
SCALE In Circuit
+G -
A 1.5 Meg.
G
- +A
1
Meg.
-
+K
-
A 1.5 Meg.
K
- +A
1.0 Meg.
G - K RXl 1.6
G - +K RXl 2.0
+G - K RX10 120
G - +K RX10 140
4.3.5 VOLTAGE READINGS IN CIRCUIT
A· Anode
G · Gate
K ·Cathode
A
K
G
G
A
K
The following are voltage readings taken with the unit operating, idling, with negative lead connected to the
main capacitor negative terminal. The positive lead is as indicated.
Table 4-13. Voltage Readings in Circuit
A . Junction R31, R28 +330 VDC
B.
Junction R28, R29 +250 VDC
c.
R29 to SCR3 Anode +230 VDC
D.
SCR3 Cathode +0.8 VDC
E. R26 to R27 +0.312 VDC
F. R20 to R21
+0.35 VDC
G.
SCR3 Gate to CR 11 Cathode
+0.8 VDC
The exact location of positive lead placement points is shown in the following PC board wiring view. (Fig. 4-4)
24
Vivitar 37460598 (11/80)
•
•
•