Canon A-1 Repair Manual page 147

I-
•
2V
•. .'.11."" .. . .
~.,.
,-.:,,:
•
Fig. 3-54
2V 21
>2
~S
-...
....
-
,
..
'
,:.'t
....
.
. -V _ _
-
. .
-:
5~
Fig . 3-55
Trigger: 07
Checkpoint: Digit 06
When checking the digit
signal gate, there is
sometimes little differ-
ence between the two
states. To improve this,
Place a 30-S0Kn resistor
from V battery or El to
the 06 . The result will
be better separation
(Wave A).
In Fig . 3-54, 06 is low
"1"
so
the gate is
open for a lighting
command from any of the
segments.
Now that we know that the digit 6 gate 1s open, we can
check Segments a thru 9 to see which segments of digit 6
are lit . From Fig. 3-55 we can see that segments a of
digits 0 2, 3, 4 and 7 are lit. Segment a of 06 1s not
lit. (Segments are -active high" i.e., a positive value
indicates a lit segment.)
81