Opt Ic (Sn28724); Nput Ic (Sn2872L) - Canon A-1 Repair Manual

3.1 OPT Ie (SN28724)
The operation of this Ie is practically identical to PX-l
in the AE-l. Refer to the AE-l Repair Guide for
individual pin outputs.
3.2 INPUT Ie (SN2872l)
1. Ivl EF (l1p)
*
*
(l1p) = pin 11
64
Input pin for the flash originate d signal which
determines the aperture to which the lens will be set
in AE flash mode (EF mode) (Signa l is present only
when eee curent is flowing)
(225 - 275
~A
+
shutter
1/60: 720 -
880~A = slow shutter
speed manual
mode)
Ivl EF = Ve(5/4
~
AV/16)
VI
= ve + Ve/16
V2
= ve
V3
=
ve - Ve/16
2. eee (12p)
f/2.8
f / ' .O
f/5.6
Fig. 3-1
Identical in principle to eee and ve in AE-l, this
signal automatically switchs the shutter speed to 1/60
when the flash is ready . The A-I ve is 1 . 2l9V + 35mV.
In addition, the A-l has a slow shutter
mode when used with the SPEEDLITE 199A.
for automatic and ma nual shutte r speeds
speed manual
The currents
are as follows.
I l
=
250~A
:I:
10%
(Shutter Speed
=
1/60, l55A
&
199A Auto)
12
=
800~A
:I:
10%
(A/T Dial 1/1000 - 1/60; AV mode
Shutter Speed
=
1/60
A/T Dial 1 /3 0 -
30;
Shutter Speed
=
Dialed speed)
*
*:
For 199A in Slow Shutter Speed
Manual Mode