Minolta 7000 - Page 17

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7. Function of encoder
AE, aperture sit plate By slit plate rotation, light from LED to photo transistor is cut
off repeatedly. Photo transistor outputs light/shade signal of
LED. Light, received by photo transistor, is converted into pulse
and input to [C,, IC, by IC,.
When
LED light
is cut off (shade)
— JUUL
AF IC, AF IC,
©.® pe Converted pulse by KC.
Aperture - '
‘ Aperture : KC. When LED light
iS received
AF: 1C,@), Aperture : ic, @
a
y eAF
; Counts pulse generated by rotation of AF slit plate inter-
locking with M; rotation, monitors AF coupler rotation
(lens shifting monitor)
AF, aperture WT
phota interruptor @ Aperture
Counts pulse generated by rotation of aperture slit plate
interlocking with stop-down operation, monitors shifting
amount of aperture ring. ,
8. Power source circuit
Vec2
| Cu
= Cu ¥ecz
¥oo.
zr. OC/DC converter
=
Ve) = Qs HK} ¥ naz
' l
4 tog
Rn Hs
| rr
\
i)
I! ton . yl
Ry He} t H moO
es 4 “4 1 t
_— =
a“ tot —
in| Du —
Lait Vu -_=
boty —e
“LL
toetOn
t Lithium battery
Cl ®
With battery holder attached, battery power is supplied to each IC as Vopo and Von.
By turning metering Sw. ON — IC, @) becomes at L —- Qs ON — DC/DC converter is activated,
stabilized power is supplied (as Vcc and Voni) Output of Vccz.
Function of lithium battery
When battery in grip is exhausted or removed for replacement, lithium battery supplies power,
through Dis, to IC; (memorizing [SO setting and frame number with indicators OFF)
When lithium battery exhaustion
IC.@ checks Vii voltage, and this signal is input through [/O Bus to IC,. If the voltage is tess
than 2.3V, attaching battery grip or turning program reset Sw. ON will make LCD “ISO” signal
and ISO setting blink for 10 sec.