Battery Check - Canon EOS 55 Service Manual

Part 2: Technical Information
2.5 Battery Check
The battery check does not use a separate load. Instead motor current is applied in the
normal and reverse directions.
The battery is checked when the battery is installed, when the dial is moved from the
Lock position, and when the shutter is released.
1.
The MPU communicates with the EFIC and selects the VBAT
/2
output from EFAD.
2. Motor current is applied in the normal and reverse directions. The current is digi-
talized through the A/D convertor and the average established.
3. The result is compared to the inhibit voltage and if it below the inhibit level, the
battery mark flashes.
MD2
RSFD,_..., 1 ~ ~ - - -
~--_...RFWD
PGNDl--'-' 12 - - - - - - + -
~-~7REV FSRD..,..
111 ~ -
~
CM 0.1
rl
f--
MD1
~
RSFDr 13
~__,--,f----J
o-+-.---=t
6 FWD PGNDr 12 ~ - - - ~
..-.+o---'-17 REV FSRD>-'-11~~ MAf f~wA
C:s:J
Fig. 2-26 Battery Check
2-34
EF IC
MPU
u..
a:
:ii :ii
VBAT
II\
CVBAT
J
0.1