Minolta XE - E. First Switching, Delay and Second Switching Circuits; F. Indication Circuit and Meter; G. Manual Resistor; H. Battery Check Circuit

E. First Switching, Delay and Second Switching Circuits
Generally speaking, the adequate exposure time cannot be easily obtained for the focal
pressure
shutter
simply
by
electrically
controlling
the
time
(lms
in
the
case
of
1/1000
sec.) corresponding to the exposure time, because there is an overlap between the first
and the second curtains. Therefore, the circuit construction is in the operational order
of the first switching circuit, the delay circuit and the second switching circuit.
In
conjunction
with
the
logarithmically
extended
part
(E
of
the
circuit
diagram)
and
the
time
set
circuit
comprising
the
condenser
Cz
or
the
manual
resistor
(G
of
the
circuit
diagram) plus the condenser C2, the first switching circuit (H of the circuit diagram)
will control the time (lms in the case of 1/1000 sec.) equal to the exposure time. The
combination
of
the
delay
circuit
(I
of
the
circuit
diagram)
with
the
second
switching
circuit
(J
of
the
circuit
diagram)
will
delay
a
certain
length
of
time
(constant
irres-
pective
of
the
exposure
time)
equivalent
to
the
“zero”
time
of
the
overlap
between
the
two
curtains,
and
will
obtain
the
exposure
time
by
controlling
the
magnet.
This
delay
action
is
mechanically
possible
by
making
the
operation
of
the
trigger
switch
well
timed,
but is much easier by an electric method. This is the reason why the electric delay
circuit is used as shown in the circuit diagram.
F. Indication Circuit and Meter
The
indication
circuit
is
intended
to
amplify
the
output
of
the
addition
circuit
and
to
operate
the
meter
inside
the
finder.
G. Manual Resistor
In
the
case
of
automatic
exposure,
the
first
switching
circuit
will
be
controlled
by
a
signal
received
from
the
extension
circuit.
In
the
case
of
manual
exposure,
however,
it
is
connectec
with
the
Ch
time
set
circuit.
In
this
case,
a
resistance
value
(1/1000
sec.
is
small
and
4
sec.
are
large)
equivalent
to
a
certain
exposure
time
(shutter
speed)
will
be
set to the condenser C.
H. Battery Check Circuit
The battery check circuit is intended to check the voltage of the power source. The lamp
will light within the range (voltage) of the accurate control of the exposure time. The
consumed
current
is
the
same
as
what
is
consumed
for
the
operation
of
the
camera.
The
lamp will light up to about 2.0V.