Ctst (2P) - Canon A-1 Repair Manual

C-
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2. CTST (2P)
2V
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J
If'
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111
*
. ; ;
V
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Fig. 3-19
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51
17,u:
Sli4
CTST
.-
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(Use SHGl trailing edge
(positive-going) trigger
and syncroscope delay)
CTST is short for count
start.
54,
the count
switch, 1s turned off when
the 1st curtain starts.
This allows CT to charge.
When
it
reaches O.62SEl ,
the count start comparator
changes states and shutter
tlmm.1ng starts .
S~14 OFF
CT Charge Curve
0 . 625E l
1. 0-1. 2V
1-- - -
O-O.lV
The count start (CTST) timing is adjusted by VRT. This
adjust the slope of the CT charge curve so the start
of the shutter timing to coincide with the time when
the leading edge of the slit just enters the aperture.
(See also Fig. 3-56, Fig . 3-57)
63