Canon A-1 Repair Manual page 51

62
button is pressed. In other words, when the
electric current is applied to the MGl (AE magnet),
it a l so flows through the MG3 (2nd curtain magnet)
at the same time and the present voltage is ex-
ami ned only for about 12 milliseconds. If this
examination turns out to be a pproved, the electric
current flows through the MG2 (1st release
magne'c.) and the camera starts to work.
In this manner, the camera i s not allowed to start
to work unless the sufficient . voltage is confirmed.
OFF_...,
N. I eN.
_...:I~----;:~­
O~
I
T.
IL.
Me3
VI> •
Exposure
---,1 .. ___ -:-::
Computatio~
r---
NC2
U
Fig . 17
2) Manual Battery Check
In manually checking the battery, electric cur-
rent is applied to the MG1 , MG2 and a registor
of some load and the degree of the remaining power
is known according to the way the LED blinks on
and off.
.
Though the flash i ng cyc le of the LED varies ac-
cordi ng to the vo lta g e (for example, in the case
of the voltage proportio n of 6V to 3V, the LED
flashes in the proportion of 4 to 1 times), if
the LED flashes two or thre e times without much
time lag the battery is considered to be good.
If there is a considerab l e lag of time between
the first flash of the LED and the following
flashes, the battery is drained.
As to the relation between the automatic battery
checking and the manual checking, since the load
in manual checking is heavier than that of
automat ~ c check ~ng ~ ho u gh the voltage is the same,
it can be said that saie ty margin is increased
for manual checking in p r o p ortion to the load.