Shutter Release - Canon EOS 55 Service Manual

Part 2: Technical Information
2.9 Shutter Release
1.
When SW2 on information is received by the MPU,
it
interupts and initiates the fol-
lowing release sequence.
2. The viewfinder LCD (ILC) is turned off by fixing the PWM output at the low level.
3. An "all stop" order is sent to the lens.
4. The battery is checked.
5. The motor is driven forward, starting the mirror up.
6. The shutter magnet is energized.
7. When the motor reaches the mirror up position on the phase board, the motor stops.
8. The diaphragm stop down signal is sent to the lens.
9. When the proper aperture is reached the diaphragm stop signal is sent.
10. Date printing starts.
11. Mg3- l is turned off and the first curtain runs.
12.After the exposure time expires, Mg3-2 is turned off and the second curtain runs.
(CN2 SW goes on, also.)
13. The battery is checked.
14. To bring the mirror down, the motor is energized.
15. When the mirror is down and the shutter is recharged, the motor stops with the
phase board at Wind phase, or at Flash phase without film or during multiple expo-
sure.
16. The motor is deenergized.
~
SW2 46
" ' .... (0
(0 (0 (0
(0
"'
w
!;,:
0
G1 FMG11
QD
Module
I I-----------
TRMG2 FMA5
MD2
RSFDl-" 1 " - - - - - - - -
~ - - F W D
PGNDl--" 12 =------+--,
~
cr----+--"C!!!:MS:,,:.P_,_1
-""I
MPU
---L-IREV
FSRDl-'- 1 ~ -
CMSP2
94
CMSP3
95
CN2
96
0
LL
w
...J
i
LL
~ ~
FLED
CM 0.1
a:
i
MD1
~
RSFDl--" 13
" - - - - - - - - j - - - j ~
~+-----------~>+---..-------"-1 6 FWD PGNDl-" 12
=---+-+----'
~--------....__tt----'-1
7 REV FSRD>-'-- 11 ~ ~
Fig. 2-30 Shutter Release
2-38