COMDYNA GP-6 - Page 9

OPERATOR'S
&
MAINTENANCE
MANUAL
+10
--€1:
~~
(>
I
CTP
Figure
2-1
Mode
SelKt.or -
-'
:
......
Hold
Inhibit
In
OPR,
+
10
volts
is
applied
through
the
COMPUTE
TIME
control
(100K
ohms)
and
a
series
1
OK
ohm
resistor
to
the
CTP
amplifier
summing
junction. A 1
OK
ohm
resistor
is
the
feedback.
Therefore:
CTP
=
-10/(CT
+
10)
x
10
volts.
In
POT
SET,
+
10
volts
is
applied
through
a
100K
ohm
resistor
to
the
CTP
summing
junction.
The
COMPUTE
TIME
control
and
1
OK
ohm
resistor
are
the
feedback.
Therefore:
CTP
=
-(CT
+
10)/100
x
10
volts.
The
CTP
amplifier
output
in
POT
SET
is
one
tenth
the
reciprocal
of
its
value
in
OPR.
As
the
CTP
output
is
the
input
to
the
time
base
integrator,
its
reciprocal
is
an
indicator
of
the
compute
time
period.
2.4.5
Hold Inhibit
One
pole
is
connected
to
the
integrator
hold
inhibit
control.
In
the
normal
integrator
initial
condition
mode,
the
hold
switch
is
shut
off,
thereby
isolating
the
input
resistor
network.
As
poten-itometers
must
be
set
with
their
resistor
loads,
it
is
necessary
to
disable
the
hold
switches
during
the
pot
set
mode.
In
POT
SET,
the
pole
is
switched
to a
positive
voltage
and
all
integrator
hold
switches
are
held
in
an
"on"
condition;
in
OPR
the
pole
is
switched
negative
and
all
integrator
all
allowed
to function
under
normal
hold
mode
control.
2.5
COMPUTE
TIME
The
COMPUTE
TIME
control
is
a
combination
1
OOK
ohm
variable
resistor
and
off-on
switch.
While
in
the
operate
mode
the
variable
resistor
is
the
CTP
amplifier
input.
The
CTP
amplifier
is
scaled
so
that
the
COMPUTE
TIME
control
adjusts
its
output
within
a
range
of
-10
volts
to
-1
volt.
The
time
base
integrator
is
scaled
so
that a
-1
O
volt
input
produces
a
compute
time
period
of
1
o
computer
seconds;
a
-1
volt input
produces
100
seconds.
The
off-on
switch
is
the
primary
AC
power
switch.
2.6
COEFFICIENT
POTENTIOMETERS
The
coefficient
potentiometers
are
ten
turn,
5K
ohm
variable
resistors.
Pots
1 -
6
are
arranged
as
attenuators
with
their
bottom
ends
grounded;
pots
7 & 8
have
their
bottom
ends
terminated
at
the
patch
panel.
2.7
OVERLOAD
INDICATORS
The
OVLD
lamp
is
a light
alarm
that
indicates
when
one
or
more
of
the
eight
patch
panel
amplifier
outputs
exceed
either
a
positive
or
negative
1
o
volts
reference.
2.8
DIGITAL
VOLTMETER
The
DVM
includes
the
features
of
3 1
/2
digits
display,
1
o
volts
full
scale
and
autopolarity.
Its
decimal
is
positioned
so
that
1
o
volts
appears
as
unity
(1.000:
a
conformance
to
normallized
or
dimensionaless
amplitude
scaling.
page
7.
-----------------------------------COM
DYNA,
INC.