COMDYNA GP-6 - Page 27

OPERATOR'S
&
MAINTENANCE
MANUAL-----------------------p-ag-e~B--,1
SCALING
REVIEW
The
following
is
offered
as
a review of analog computer programming magnitude and
time scaling.
EXAMPLE
DIFFERENTIAL
EQUATION
I
Ad
2
:X,,dt
2
+
B
dX/dt
+
C X
=
f(t)I
+REF
-----t
Lf,
-------<
program
schematic
Given:
A
=
.0005
Estimated
maximum
values:
B (arbitrary)
Xmax.
.01
Xscaled
=
[X/.01]
C
=
800
dX/dt
max.
= 4
dX/dt
scaled
=
[dX /ctt/4]
f(t)
=
.5
Rewritten
and
scaled:
B
C
.01
1
[iX;d?/4]
= - -
[dX/dt/4]
-- x -
[X/.01]
+-
[f(t)/4]
Af3 Af3
4
Af3
f3
time scale facto;r
Potentiometer Settings
No.
Parameter
magnitude
scale
factor
w/o
time
scale
w/time
scale,
{3
=
500
1.
f(t)/A
1/4
.25x10
1/3
.500
2.
B/A
1
2Bx10
1(3
40B
3.
dXsf!Xsf
4/.01
.4x10
1(3
.800
4.
CIA
.01/4
.16x10
1(3
.320
5.
dXo/dt
1/4
dXo;aJ4
aXo;ctJ4
6.
Xo
1/.01
Xo/.01
Xo/.01
---------------------------------COM
DYNA,
INC.