GP-6 Analog Computer Operator's Manual
GP-6 ANALOG COMPUTER
OPERATOR'S MANUAL
OPERATOR'S
MANUAL
1. GP-6 OPERATING PROCEDURES
1.0
CONNECTION OF EXTERNAL READOUT INSTRUMENTS
The GP-6 f u n c t i o n s i n t h e s l o w t i m e a n d / o r h i g h s p e e d r e p e t i t i v e o p e r a t i o n modes.
S l o w t i m e o u t p u t s a r e n o r m a l l y r e c o r d e d w i t h a n XY p l o t t e r ;
repetitive operation
o u t p u t s a r e n o r m a l l y d i s p l a y e d w i t h a n o s c i l l o s c o p e h a v i n g D C h o r i z o n t a l and v e r t i cal inputs.
S l o w t i m e o u t p u t s a l s o may be r e c o r d e d w i t h a s t r i p c h a r t r e c o r d e r ;
r e p e t i t i v e o p e r a t i o n o u t p u t s a l s o may b e d i s p l a y e d w i t h a n o s c i l l o s c o p e h a v i n g a
DC v e r t i c a l i n p u t a n d an i n t e r n a l t i m e b a s e w i t h an e x t e r n a l t r i g g e r .
I t i s n o t e d t h a t t h e GP-6 i s f u r n i s h e d w i t h v a r i o u s o p t i o n s
f o r c o n n e c t i o n and c a l i b r a t i o n o f r e a d o u t i n s t r u m e n t s .
1.
2.
3.
4.
t h a t must b e c o n s i d e r e d
S l o w t i m e o n l y (no i n t e r n a l t i m e b a s e . )
S l o w t i m e o n l y ( i n t e r n a l t i m e base p r o v i d e d . )
H i g h s p e e d r e p e t i t i v e o p e r a t i o n o n l y ( i n t e r n a l t i m e base p r o v i d e d . )
Slow t i m e and r e p e t i t i v e o p e r a t i o n ( i n t e r n a l s l o w and h i g h speed
t i m e bases p r o v i d e d . )
Rear t e r m i n a l s o n t h e GP-6 o f f e r c o n v e n i e n t c o n n e c t i o n s t o t h e X and Y i n p u t s
t h e p l o t t e r a n d / o r o s c i l l o s c o p e . The t h r e e c o n n e c t i o n s a r e shown i n F i g . 1-1
and l i s t e d b e l o w :
1.
2.
3.
of
Common g r o u n d .
"Y OUTPUT" t o t h e p l o t t e r a n d / o r o s c i l l o s c o p e Y ( v e r t i c a l ) i n p u t ,
"X OUTPUT" t o t h e p l o t t e r a n d / o r o s c i l l o s c o p e X ( h o r i z o n t a l ) i n p u t .
I f t h e o s c i l l o s c o p e ' s i n t e r n a l t i m e base and e x t e r n a l t r i g g e r i s t o b e used f o r
d i s p l a y o f r e p e t i t i v e s o l u t i o n s , the e x t e r n a l t r i g g e r i n p u t should b e connected t o
t h e "OP OUTPUT" r e a r t e r m i n a l .
The OP O u t p u t mode c o n t r o l l o g i c i s a c o n v e n i e n t
t r i g g e r for r e p e t i t i v e outputs.
1.1
CALIBRATION OF READOUT INSTRUMENTS
The r e a d o u t p l o t t e r o r o s c i l l o s c o p e i s c a l i b r a t e d so t h a t t h e f u l l s c a l e h o r i z o n t a l
and v e r t i c a l axes e x t e n d b e t w e e n t h e c o m p u t e r ' s n e g a t i v e and p o s i t i v e r e f e r e n c e
( m i n u s t o p l u s t e n v o l t s ) as shown i n F i g . 1-2.
Positive
f u l l scale
position
Center p o s i t i o n
Negative
full
scale
position
Figure
1-2
COMDYMA,
Inc.
X AXIS
OPERATOR'S
The
MANUAL
following
are
procedures
for
input
scaling
adjustments:
1 . P o s i t i o n t h e Mode S e l e c t o r s w i t c h t o "OPR."
2. D e p r e s s t h e "1C" mode c o n t r o l p u s h b u t t o n .
3. P o s i t i o n b o t h t h e "Y/POT ADDRESS" a n d "X ADDRESS" s w i t c h e s t o "GND."
4.
A d j u s t t h e p l o t t e r o r o s c i l l o s c o p e Y and X z e r o c o n t r o l s u n t i l t h e
p l o t t e r ' s pen o r o s c i l l o s c o p e ' s d o t i s i n t h e g r a p h o r d i s p l a y c e n t e r
p o s i t i o n a s shown i n F i g . 1-2.
5. P o s i t i o n t h e "Y/POT ADDRESS" a n d "X ADDRESS" s w i t c h e s t o "-REF."
6.
A d j u s t t h e p l o t t e r o r o s c i l l o s c o p e Y and X s c a l e c o n t r o l s u n t i l t h e
p l o t t e r ' s pen o r o s c i l l o s c o p e ' s d o t i s i n t h e g r a p h o r d i s p l a y n e g a t i v e
f u l l s c a l e p o s i t i o n as shown i n F i g . 1-2.
7. P o s i t i o n t h e "Y/POT ADDRESS" a n d "X ADDRESS" s w i t c h e s t o "+REF."
8. Check t h e p e n o r d o t .
I t s h o u l d be i n t h e p o s i t i v e f u l l s c a l e p o s i t i o n .
9 . Repeat t h e above p r o c e d u r e s i f n e c e s s a r y .
The r e a d o u t i n s t r u m e n t s a r e c a l i b r a t e d t o p r e s e n t e i t h e r Y v s Time o r Y v s X c u r v e s
d e p e n d i n g o n t h e p o s i t i o n s o f t h e Y and X a d d r e s s s w i t c h e s .
A m p l i f i e r o u t p u t s app e a r as v a r i a b l e s t h a t f u n c t i o n w i t h i n t h e i r f u l l s c a l e n e g a t i v e a n d p o s i t i v e o p e r a t i n g ranges.
The t i m e b a s e i s p r e s e n t e d so t h a t t h e n e g a t i v e f u l l s c a l e c o - o r d i n a t e
i s a zero t i m e c o n d i t i o n and t h e p o s i t i v e f u l l s c a l e c o - o r d i n a t e i s the compute time
period.
Time c o - o r d i n a t e s , t h e r e f o r e , depend o n t h e o p e r a t o r ' s c h o i c e o f a t i m e
p e r i o d t h a t i s a d j u s t a b l e w i t h i n a r a n g e o f 1 0 t o 100 c o m p u t e r t i m e s c a l e d s e c o n d s .
I f t h e o s c i l l o s c o p e i n t e r n a l t i m e base i s t o b e u s e d f o r t h e r e p e t i t i v e d i s p l a y ,
t h e h i g h s p e e d t i m e s c a l e r a t i o o f 4 0 0 : 1 m u s t be c o n s i d e r e d .
One c o m p u t e r t i m e
s c a l e d s e c o n d i s e q u a l t o 2.5 m i l l i s e c o n d s o f r e a l t i m e .
1.2
SETTING COEFFICIENT POTENTIOMETERS
C o e f f i c i e n t s a r e s e t i n a p o t e n t i o m e t e r s e t t i n g mode w i t h t h e i n t e r n a l r e a d o u t m e t e r
t h a t i s e i t h e r a d i g i t a l v o l t m e t e r o r n u l l meter depending o n the o p t i o n t h a t i s
furnished.
Procedures f o r s e t t i n g c o e f f i c i e n t p o t e n t i o m e t e r s are l i s t e d a s f o l l o w s :
1.
2.
3.
4a
4b
1.3
C o e f f i c i e n t s are set a f t e r a l l p a t c h i n g i s completed.
( I t i s noted that
when u s e d a s n o r m a l a t t e n u a t o r s t h e b o t t o m ends o f p o t e n t i o m e t e r s 7 and
8 must b e p a t c h e d t o g r o u n d . )
P o s i t i o n t h e "MODE SELECTOR" s w i t c h t o "POT SET."
P o s i t i o n t h e "Y/POT ADDRESS" s w i t c h t o t h e number o f t h e p o t e n t i o m e t e r
t o be s e t .
Where t h e d i g i t a l v o l t m e t e r i s e m p l o y e d t h e c o e f f i c i e n t v a l u e i s d i s played.
A d j u s t the p o t e n t i o m e t e r u n t i l the d e s i r e d s e t t i n g i s observed.
Where t h e n u l l m e t e r i s e m p l o y e d t h e p o t e n t i o m e t e r m u s t be n u l l e d
against a preset p o t e n t i a l . P r i o r to s e t t i n g the c o e f f i c i e n t p o t e n t i o m e t e r a d j u s t t h e n u l l p o t e n t i o m e t e r u n t i l t h e c a l i b r a t e d d i a l shows t h e
desired c o e f f i c i e n t value.
Place the adjacent t o g g l e s w i t c h in the up
position.
Adjust the c o e f f i c i e n t p o t e n t i o m e t e r u n t i l the n u l l meter
needle i s i n a n u l l ( c e n t e r ) p o s i t i o n .
SETTING THE COMPUTE TIME PERIOD
The Compute T i m e P e r i o d i s t h e f u l l s c a l e X a x i s c o - o r d i n a t e f o r r e s p o n s e c u r v e s
p r o d u c e d b y t h e XY p l o t t e r o r d i s p l a y e d o n t h e o s c i l l o s c o p e when t h e c o m p u t e r ' s
i n t e r n a l t i m e base i s e m p l o y e d .
P r o c e d u r e s f o r s e t t i n g t h e Compute Time P e r i o d a r e a s f o l l o w s :
(Note- o n l y u n i t s
f u r n i s h e d w i t h t h e i n t e r n a l t i m e b a s e h a v e t h e Compute T i m e P e r i o d s e t t i n g f e a t u r e . )
1 . P o s i t i o n t h e "MODE SELECTOR" s w i t c h t o "POT SET."
2. P o s i t i o n t h e "Y/POT ADDRESS" s w i t c h t o "GND/X."
3. P o s i t i o n t h e X ADDRESS" s w i t c h t o "CTP."
4a
Where t h e d i g i t a l r e a d o u t i s e m p l o y e d , t h e d i s p l a y shows CTP/100 comp u t e r time s c a l e d seconds.
A d j u s t t h e "COMPUTE TIME" c o n t r o l u n t i l
t h e d e s i r e d Compute Time P e r i o d i s o b s e r v e d .
4b
Where t h e n u l l m e t e r i s e m p l o y e d , f i r s t s e t t h e n u l l p o t e n t i o m e t e r t o
t h e d e s i r e d CTP/100 v a l u e .
Place the a d j a c e n t t o g g l e s w i t c h i n t o the
down p o s i t i o n .
A d j u s t t h e "COMPUTE TIME" c o n t r o l u n t i l a n u l l c o n d i t i o n
i s observed.
COMDYNA, Inc.
OPERATOR'S MANUAL
1.4
STATIC MEASUREMENT OH A M P L I F I E R OUTPUTS
The a m p l i f i e r a d d r e s s a n d i n t e r n a l r e a d o u t m e t e r may be u s e d f o r t h e s t a t i c measurement o f a m p l i f i e r o u t p u t s .
1.4.1 M e a s u r e m e n t o f a m p l i f i e r o u t p u t s i n t h e P o t S e t mode.
s w i t c h i s i n t h e "POT SET" p o s i t i o n . )
1.
2.
3a
3b
1.4.2
switch
P o s i t i o n t h e "Y/POT ADDRESS" s w i t c h t o "GND/X."
P o s i t i o n t h e "X ADDRESS" s w i t c h t o t h e number o f t h e a m p l i f i e r o u t p u t
to be measured.
Where t h e d i g i t a l r e a d o u t i s e m p l o y e d t h e a d d r e s s e d a m p l i f i e r o u t p u t
is displayed.
I t s p o l a r i t y is automatically indicated.
Where t h e n u l l m e t e r i s e m p l o y e d f i r s t t h e t o g g l e s w i t c h m u s t be i n
the p o s i t i o n f o r the c o r r e c t output p o l a r i t y .
I f the a m p l i f i e r output
i s p o s i t i v e t h e t o g g l e s w i t c h must b e i n t h e u p p o s i t i o n ;
i f the output
i s n e g a t i v e t h e t o g g l e s w i t c h m u s t be down.
Adjust the n u l l potentiometer u n t i l a n u l l c o n d i t i o n i s observed.
The n u l l p o t e n t i o m e t e r d i a l
r e a d i n g i s t h e measured a m p l i f i e r o u t p u t .
M e a s u r e m e n t o f a m p l i f i e r o u t p u t s i n t h e O p e r a t e mode.
i s i n t h e "OPR" p o s i t i o n . )
1.
2.
3.
( T h e "MODE SELECTOR"
( T h e "MODE SELECTOR"
P a t c h t h e r e a r t e r m i n a l "Y OUTPUT" t o r e a r t e r m i n a l "METER INPUT."
P o s i t i o n t h e "Y/POT ADDRESS" s w i t c h t o t h e number o f t h e a m p l i f i e r o u t p u t to be measured.
F o l l o w above p r o c e d u r e s 3 a o r 3 b t o m e a s u r e t h e d e s i r e d a m p l i f i e r
output.
1.4.3
M e a s u r i n g t h e sum o f i n t e g r a t o r i n p u t s .
The sum o f i n t e g r a t o r i n p u t s , a s
r c q u i r e d in s t a n d a r d p r o g r a m s t a t i c c h e c k p r o c e d u r e s , may be m e a s u r e d as f o l l o w s :
1.
2.
3.
4.
1.5
P o s i t i o n t h e "MODE SELECTOR" s w i t c h t o "OPR."
D e p r e s s t h e " I C " mode c o n t r o l p u s h b u t t o n .
P a t c h t h e "SJ" j a c k o f t h e i n t e g r a t o r i n p u t t o b e measured t o t h e "SJ"
j a c k o f a n u n u s e d a m p l i f i e r ; t h e u n u s e d a m p l i f i e r i s t o have a 1 r e s istor feedback.
M e a s u r e t h e summer a m p l i f i e r o u t p u t u s i n g t h e p r o c e d u r e s o f 1.4.2.
The summer o u t p u t i s t h e i n v e r t e d sum o f t h e i n t e g r a t o r i n p u t s .
PROBLEM SOLUTION
Problem s o l u t i o n i s o r i e n t e d p r i m a r i l y t o the X Y graph o r d i s p l a y .
Following prog r a m m i n g , p a t c h i n g , s e t t i n g o f c o e f f i c i e n t s , p r o g r a m c h e c k o u t a n d s e t t i n g t h e compute t i m e p e r i o d , t h e program is ready to be r u n .
Computed v a r i a b l e s a r e r e a d y t o
be r e c o r d e d ,
d i s p l a y e d and e v a l u a t e d .
The p r i n c i p l e g r a p h i c a l r e a d o u t i s t h e r e s p o n s e c u r v e w h e r e d e p e n d e n t v a r i a b l e s
( a m p l i f i e r o u t p u t s ) are presented as f u n c t i o n s of the independent v a r i a b l e time.
To o b t a i n response curves:
1.
2.
3a
4a
3b
P o s i t i o n t h e "Y/POT ADDRESS" s w i t c h t o t h e number o f t h e a m p l i f i e r o u t put t h a t is to be the curve's o r d i n a t e .
P o s i t i o n t h e "X ADDRESS" s w i t c h t o "TIME."
F o r XY p l o t t e r r e a d o u t , d e p r e s s t h e " I C " mode c o n t r o l p u s h b u t t o n .
( A l l i n t e g r a t o r s a r e p l a c e d i n t o t h e i n i t i a l c o n d i t i o n mode.)
D e p r e s s t h e "OP" p u s h b u t t o n .
( A l l i n t e g r a t o r s are simultaneously
p l a c e d i n t o a n o p e r a t e o r r u n s t a t e and t h e p l o t t e r p r o d u c e s t h e
Y v s Time r e s p o n s e c u r v e . )
F o r o s c i l l o s c o p e r e a d o u t , d e p r e s s t h e "RO" mode c o n t r o l p u s h b u t t o n .
(The r e s p o n s e o f a l l i n t e g r a t o r s i s i n c r e a s e d b y a f a c t o r o f 400; a l l
integrators are
repeatedly
switched from i n i t i a l c o n d i t i o n t o operate
modes a n d t h e c o m p l e t e r e s p o n s e c u r v e s a p p e a r o n t h e o s c i l l o s c o p e
display.
COMDYNA, Inc.
OPERATOR'S
MANUAL
I f the response curve i s t o b e e v a l u a t e d i n p h y s i c a l u n i t s , the a m p l i f i e r o u t p u t
s c a l e f a c t o r (maximum e s t i m a t e d a m p l i t u d e ) i s t h e f u l l s c a l e Y a x i s c o - o r d i n a t e and
t h e f u n c t i o n o p e r a t e s w i t h i n t h e range o f zero t o p l u s o r minus t h e s c a l e f a c t o r
value.
The f u l l s c a l e r e a l t i m e c o - o r d i n a t e i s t h e c o m p u t e t i m e p e r i o d d i v i d e d by
the time scale f a c t o r .
I f t h e o p e r a t o r d e t e r m i n e s t h a t t h e compute t i m e p e r i o d i s e i t h e r t o o l o n g o r t o o
s h o r t f o r c o n v e n i e n t r e a d o u t , t h e "COMPUTE TIME" c o n t r o l may be a d j u s t e d and a new
compute t i m e p e r i o d e s t a b l i s h e d .
I t i s e m p h a s i z e d t h a t a d j u s t m e n t o f t h e "COMPUTE
TIME" c o n t r o l d o e s n o t a l t e r t h e r e s p o n s e f u n c t i o n b u t v a r i e s o n l y t h e p e r i o d t h a t
i s observed.
( I f t h e f u l l r a n g e "COMPUTE TIME" c o n t r o l a d j u s t m e n t d o e s n o t meet
r e a d o u t r e q u i r e m e n t s , a new t i m e s c a l e f a c t o r must b e s e l e c t e d and c o e f f i c i e n t
settings recalculated.)
An a l t e r n a t e g r a p h i c a l readout is the phase-plane curve (a v a r i a b l e p l o t t e d
a g a i n s t i t s d e r i v a t i v e ) o r a c u r v e o f one v a r i a b l e p l o t t e d a g a i n s t a n o t h e r v a r i able.
To p r o d u c e s u c h c u r v e s p o s i t i o n t h e "X ADDRESS" s w i t c h t o t h e a m p l i f i e r o u t p u t t h a t i s t o b e t h e a b s c i s s a and f o l l o w above p r o c e d u r e s 3 a and 4 a o r 3b.
I t i s noted t h a t the curves d i s p l a y e d o n the o s c i l l o s c o p e are i d e n t i c a l t o graphs
produced b y the X Y p l o t t e r .
I f t h e o s c i l l o s c o p e and p l o t t e r a r e u s e d f o r t h e simu l a t i o n a n a l y s i s i t i s c o n v e n i e n t t o c o n n e c t b o t h r e a d o u t i n s t r u m e n t s and l e a v e t h e
p l o t t e r i n a s t a n d - b y c o n d i t i o n when n o t b e i n g u s e d .
The a n a l y s i s may t h e n be c o n ducted as f o l l o w s :
1 .
2.
3.
4.
E v a l u a t e f u n c t i o n s i n t h e r e p e t i t i v e o p e r a t i o n mode w i t h t h e o s c i l loscope d i s p l a y .
A v i e w o f t h e t o t a l o u t p u t c u r v e s and t h e q u i c k r e sponse t o p a r a m e t e r changes i s o f t e n v a l u a b l e t o a n u n d e r s t a n d i n g o f
problem c h a r a c t e r i s t i c s .
When h a r d c o p y i s d e s i r e d t h e c u r v e may t h e n
be p l o t t e d .
D e p r e s s t h e " I C " mode c o n t r o l p u s h b u t t o n .
A c t i v a t e the p l o t t e r .
D e p r e s s t h e "OP" p u s h b u t t o n and p l o t t h e c u r v e t h a t was d i s p l a y e d o n
the o s c i l l o s c o p e .
I n a d d i t i o n t o t h e i n i t i a l c o n d i t i o n a n d o p e r a t e modes d e s c r i b e d i n a b o v e p r o c e d u r e s
3 a and 4 a , o u t p u t f u n c t i o n s may b e p l a c e d i n t o a h o l d c o n d i t i o n .
A t any t i m e d u r i n g
a r u n c o m p u t e r t i m e may be s t o p p e d b y d e p r e s s i n g t h e "HD" mode c o n t r o l p u s h b u t t o n .
The h o l d mode e n a b l e s t h e o p e r a t o r t o e v a l u a t e t h e s t a t i c v a l u e s o f v a r i a b l e a t des i r e d p o i n t s i n t i m e . From t h e h o l d mode t h e r u n may e i t h e r be c o n t i n u e d by r e d e p r e s s i n g t h e "OP" p u s h b u t t o n o r t h e f u n c t i o n may be r e t u r n e d t o t h e i n i t i a l cond i t i o n s t a t e b y d e p r e s s i n g the " I C " push b u t t o n .
1.6
SLAVING TWO OR MORE COMPUTERS
When p r o b l e m r e q u i r e m e n t s e x c e e d t h e c a p a c i t y o f one u n i t t w o o r more GP-6 comp u t e r s may b e s l a v e d i n t o a s i n g l e o p e r a t i n g s y s t e m .
1.
2.
3.
4.
5.
6.
1.7
Designate a u n i t to be the master; o t h e r s s h a l l then be s l a v e s to the
master.
C o n n e c t a common g r o u n d b e t w e e n u n i t s t h r o u g h r e a r t e r m i n a l s "GND."
P r o g r a m e a c h u n i t and t h e n p a t c h i n t e r c o n n e c t i o n s .
P a t c h i n g between
panels is i d e n t i c a l to patching w i t h i n a panel.
O n a l l s l a v e u n i t s remove t h e s h o r i n g w i r e b e t w e e n r e a r t e r m i n a l s
"OP OUTPUT" a n d "OP INPUT."
C o n n e c t t h e r e a r t e r m i n a l "OP OUTPUT" o f t h e m a s t e r t o t h e "OP INPUT"
terminals o f a l l slave u n i t s .
The modes o f a l l s l a v e d u n i t s w i l l t h e n be c o n t r o l l e d by o p e r a t i o n
of t h e master computer.
POWER
The 115 v o l t A.C. p o w e r s w i t c h i s a p a r t o f t h e Compute Time c o n t r o l .
To t u r n
p o w e r " o n " r o t a t e t h e Compute Time c o n t r o l c l o c k w i s e f r o m t h e "OFF" p o s i t i o n .
The
above p i l o t l i g h t i n d i c a t e s a p o w e r - o n c o n d i t i o n .
COMDYNA, Inc.
OPERATOR'S M A N U A L
2. GP-6 OPERATOR FUNCTIONS
Figure 2 - 1
REAR TERMINALS
Y/POT ADDRESS
X ADDRESS
MODE SELECTOR
2.0 GP-6 OPERATOR FUNCTIONS
F i g u r e 2-1 i s a s c h e m a t i c o f o p e r a t o r f u n c t i o n s .
f u n c t i o n s are described i n the f o l l o w i n g .
2.1
Descriptions of
individual
Y/POT ADDRESS
The Y/Pot A d d r e s s s w i t c h i s a n 1 1 p o s i t i o n , 2 p o l e r o t a r y s w i t c h .
One s e c t i o n sel e c t s a m p l i f i e r outputs f o r e x t e r n a l readout; the o t h e r s e c t i o n s e l e c t s c o e f f i c i e n t
p o t e n t i o m e t e r o u t p u t s Cor s e t t i n g a t t e n u a t o r c o n s t a n t s .
The a m p l i f i e r s e l e c t o r
w i p e r i s c o n n e c t e d t o t h e r e a r t e r m i n a l "Y OUTPUT;" t h e p o t e n t i o m e t e r s e l e c t o r i s
c o n n e c t e d t o t h e Mode S e l e c t o r s w i t c h a n d i s t h e i n p u t t o t h e i n t e r n a l r e a d o u t m e t e r
i n t h e P o t S e t mode. T t i s n o t e d t h a t t h e "GND/X" p o s i t i o n o f t h e p o t e n t i o m e t e r
s e c t i o n is connected to the X Address s w i t c h w i p e r so t h a t the i n t e r n a l readout
m e t e r may be u s e d t o m e a s u r e t h e X A d d r e s s s e l e c t i o n s i n t h e P o t S e t mode.
COMDYNA, Inc.
OPERATOR'S
2.2
MANUAL
X ADDRESS
The X A d d r e s s s w i t c h i s a n 1 1 p o s i t i o n , 1 p o l e r o t a r y s w i t c h .
It selects a m p l i f i e r
o u t p u t s , t h e i n t e r n a l t i m e base and t h e CTP o u t p u t f o r b o t h e x t e r n a l and i n t e r n a l
r e a d o u t . The w i p e r i s c o n n e c t e d t o t h e r e a r t e r m i n a l "X OUTPUT" a n d t h e "GND/X"
p o s i t i o n o f t h e Y/Pot A d d r e s s s w i t c h , p o t e n t i o m e t e r s e c t i o n .
2.3 MODE SELECTOR
The Mode S e l e c t o r s w i t c h i s a 2 p o s i t i o n , 12 p o l e r o t a r y s w i t c h . I t p r o v i d e s a numb e r o f f u n c t i o n s t h a t d i s t i n g u i s h t h e c o m p u t e r ' s P o t S e t a n d O p e r a t e modes.
2.3.1
Setting of C o e f f i c i e n t Potentiometers
The t o p end i n p u t t o each c o e f f i c i e n t p o t e n t i o m e t e r i s c o n n e c t e d t o one o f 8
poles.
I n t h e OPR p o s i t i o n t h e p o l e s a r e s w i t c h e d t o t h e p a t c h p a n e l i n p u t ; i n
t h e POT SET p o s i t i o n t h e p o l e s a r e s w i t c h e d t o p o s i t i v e r e f e r e n c e .
Thus i n t h e
P o t S e t mode t h e i n p u t s t o a l l p o t e n t i o m e t e r s a r e r e p l a c e d b y p o s i t i v e r e f e r e n c e
and t h e p o t e n t i o m e t e r o u t p u t v a l u e s a r e measurements o f v o l t a g e d i v i d e r r a t i o s .
2.3.2
I n t e r n a l Readout M e t e r
One p o l e i s c o n n e c t e d t o t h e i n t e r n a l r e a d o u t m e t e r i n p u t .
I n t h e POT SET posi t i o n t h e p o l e i s s w i t c h e d t o t h e X A d d r e s s s w i t c h w i p e r ; i n t h e OPR p o s i t i o n t h e
p o l e i s s w i t c h e d t o t h e r e a r t e r m i n a l "METER INPUT."
2.3.3
I n t e g r a t o r Mode C o n t r o 1
One p o l e i s c o n n e c t e d t o t h e r e a r t e r m i n a l "OP OUTPUT." I n t h e P o t S e t mode t h e
p o l e i s s w i t c h e d t o g r o u n d ; i n t h e OPR p o s i t i o n t h e p o l e i s s w i t c h e d t o t h e p u s h
b u t t o n mode c o n t r o l s e l e c t i o n . Thus i n t h e P o t S e t mode a l l i n t e g r a t o r s a r e
p l a c e d i n t o an i n i t i a l c o n d i t i o n s t a t e ; i n t h e OPR mode i n t e g r a t o r s a r e c o n t r o l l e d
by t h e p u s h b u t t o n mode s w i t c h e s .
2.3.4
CTP A m p l i f i e r
Two p o l e s a r e u s e d t o p r o g r a m t h e CTP a m p l i f i e r a s shown i n
The CTP a m p l i f i e r i s l o c a t e d o n t h e T i m e r b o a r d a s s e m b l y .
Figures
2-1
and
2-2.
Figure
2-2
Time Base
Hold I n h i b i t
I n t h e OPR p o s i t i o n , p o s i t i v e r e f e r e n c e i s a p p l i e d t h r o u g h t h e Compute Time c o n t r o l ( 1 0 0 K ohms) and a s e r i e s 10K ohm r e s i s t o r t o t h e CTP a m p l i f i e r summing junc
tion.
A 10K ohm r e s i s t o r i s t h e f e e d b a c k , t h e r e f o r e ,
CTP =
-10/(CT + 10)
x Reference.
i n t h e POT S E T p o s i t i o n , p o s i t i v e r e f e r e n c e i s a p p l i e d t h r o u g h a 100K ohm r e s i s t o r
t o t h e CTP a m p l i f i e r summing j u n c t i o n . The Compute Time c o n t r o l a n d 10K ohm r e s i s t o r i s the feedback, t h e r e f o r e ,
CTP =
-(CT +
10)/100 x Reference.
The CTP a m p l i f i e r o u t p u t i n t h e POT SET p o s i t i o n i s one t e n t h t h e r e c i p r o c a l o f
i t s v a l u e i n t h e OPR p o s i t i o n .
A s t h e CTP o u t p u t i s t h e i n p u t t o t h e t i m e base
i n t e g r a t o r , i t s r e c i p r o c a l i s a m e a s u r e m e n t o f t h e Compute T i m e P e r i o d .
2.3.5
Hold I n h i b i t
I n t h e n o r m a l i n t e g r a t o r i n i t i a l c o n d i t i o n mode t h e h o l d s w i t c h i s s h u t o f f , t h e r e b y
i s o l a t i n g the input r e s i s t o r network.
I t i s n e c e s s a r y , however, t o set p o t e n t i o meters w i t h t h e i r r e s i s t o r loads connected.
T h e r e f o r e , d u r i n g t h e p o t s e t mode each
COMDYNA, Inc.
3. GP-6 PATCH PANEL
Patch panel g r a p h i c s r e p r e s e n t n e t w o r k s a s t h e y a r c a p p l i e d i n normal a n a l o g computer
programming.
A m p l i f i e r s 1 t h r u 6 may be u s e d as summers o r h i g h g a i n o p e r a t i o n a l amp l i f i e r s ; a m p l i f i e r s 1 t h r u 4 h a v e e l e c t r o n i c s w i t c h n e t w o r k s a n d may a l s o be p r o g r a m med a s i n t e g r a t o r s , t r a c k / s t o r e a m p l i f i e r s and s i n g l e p o l e , d o u b l e t h r o w e l e c t r o n i c
switches.
A m p l i f i e r s 7 and 8 a r e i n v e r t e r s .
Potentiometers 1 t h r u 6 are a t t e n u a t o r s .
P o t e n t i o m e t e r s 7 a n d 8 have t h e i r b o t t o m ends o p e n a n d may be u s e d as v o l t a g e d i v i d e r s
or a t t e n u a t o r s .
M u l t i p l i e r n e t w o r k s have c u r r e n t o u t p u t s ; w i t h one a m p l i f i e r each may
h e used a s a m u l t i p l i e r , d i v i d e r , s q u a r e r o r s q u a r e r o o t e x t r a c t o r .
The
following
SYMBOL
is
a d e s c r i p t i o n of patch panel
symbols:
COLOR CODE
DESCRIPTION
Red
P o s i t i v e reference, considered u n i t y ,
1.0
f o r normalized
programming.
(Actual amplitude is 10 v o l t s . )
Yellow
Negative reference
High g a i n o p e r a t i o n a l
amplifier.
High
amplifier
gain
operational
with
electronic
switch.
Inverter
Red
Amplifier
output.
Gray
The summing j u n c t i o n f o r a m p l i f i e r s 1 t h r u 6. ( A c t i v e f o r
a m p l i f i e r s 1 t h r u 4 when a l o g i c " 1 " i s a p p l i e d t o t h e "SW"
s w i t c h c o n t r o l j a c k o r when t h e r e i s no s w i t c h c o n t r o l
patching.)
COMDYNA, Inc.
OPERATORS
SYMBOL
MANUAL
DESCRIPTION
COLOR CODE
Gray
A l t e r n a t e summing j u n c t i o n f o r a m p l i f i e r s 1 t h r u 4.
(Active
when a l o g i c " 0 " i s a p p l i e d t o t h e "SW" s w i t c h c o n t r o l j a c k . )
Green
S t a n d a r d i n p u t summing r e s i s t o r , n o r m a l i z e d as a u n i t y v a l u e
t o s i m p l i f y p r o g r a m m i n g . ( A c t u a l v a l u e i s 50 K ohms.)
Green
Summing r e s i s t o r i n p u t t h a t h a s a v a l u e o n e t e n t h t h e s t a n dard.
( A c t u a l v a l u e i s 5 k ohms.)
Green
S t a n d a r d i n t e g r a t i n g c a p a c i t o r i n p u t , n o r m a l i z e d s o t h a t the
1 r e s i s t o r and B c a p a c i t o r c o m b i n a t i o n p r o d u c e s a one second
time c o n s t a n t as r e f e r r e d to programming t i m e s c a l e s .
(Actual
v a l u e i s 20 u f d i n t h e s l o w t i m e mode a n d .05 u f d i n t h e r e p e t i t i v e o p e r a t i o n mode.)
Green
I n t e g r a t i n g c a p a c i t o r i n p u t t h a t has a v a l u e one t e n t h t h e
s t a n d a r d . ( A c t u a l v a l u e i s 2 u f d i n t h e s l o w t i m e mode and
.005 u f d i n t h e r e p e t i t i v e o p e r a t i o n mode.)
Green
R e s i s t o r i n p u t t o t h e S J ' summing j u n c t i o n . A m p l i f i e r becomes
an i n v e r t e r when S J ' i s a c t i v e .
N o r m a l l y used f o r i n t e g r a t o r
i n i t i a l conditions.
I n p u t a n d f e e d b a c k r e s i s t o r s may be used
f o r summer o p e r a t i o n b y p a t c h i n g S J ' t o S J .
(Actual value o f
i n p u t a n d f e e d b a c k r e s i s t o r i s 50 k ohms.)
Yellow
Attenuator,
symbol.
Yellow
V o l t a g e d i v i d e r ; t o p , b o t t o m and w i p e r i n d i c a t e d b y s t a n d a r d
e l e c t r i c a l symbol.
B o t t o m m u s t be p a t c h e d t o g r o u n d f o r
attenuator operation.
( P o t e n t i o m e t e r v a l u e i s 5 k ohms.)
Black
System g r o u n d .
Multiplier
input
and
wiper
indicated
by
standard
electrical
network.
Brown
One o f t w o m u l t i p l i e r i n p u t s .
Brown
One o f t w o m u l t i p l i e r i n p u t s .
Brown
M u l t i p l i e r output, a current proportional t o t h e product of
i n p u t s "X" a n d "Y"; n o r m a l i z e d so t h a t when c o n n e c t e d t o t h e
summing j u n c t i o n o f an o p e r a t i o n a l a m p l i f i e r w i t h a 1 r e s i s t o r f e e d b a c k , and w i t h r e f e r e n c e a p p l i e d t o "X" and "Y",
the a m p l i f i e r output equals r e f e r e n c e .
White
Electronic switch control input.
W i t h a l o g i c "0" (ground
o r p o s i t i v e v o l t a g e ) t h e S J ' summing j u n c t i o n o f t h e above
a m p l i f i e r i s a c t i v e and S J s h u t s o f f .
With a l o g i c " 1 "
(-5 t h r u -15 v o l t s ) S J i s a c t i v e and SJ' s h u t s o f f .
With
"HD" l o g i c (-2 t h r u -3 v o l t s ) S J ' s h u t s o f f , t h e SJ summing
j u n c t i o n i s a c t i v e b u t t h e summing r e s i s t o r n e t w o r k i s d i s connected. "IID" l o g i c i s used f o r normal i n t e g r a t o r h o l d
mode o p e r a t i o n .
White
The c o m p u t e r ' s o p e r a t e b u s ; p r o v i d e s i n t e g r a t o r mode l o g i c
( s l o w t i m e , r e p e t i t i v e o p e r a t i o n o r s l a v e ) a s s e l e c t e d b y the
operator.
N o r m a l i n t e g r a t o r o p e r a t i o n r e q u i r e s t h a t t h e "OP"
bus b e p a t c h e d t o t h e "SW" s w i t c h c o n t r o l
input.
COMDYNA, Inc.
OPERATOR'S MANUAL
PATCH PANEL OPERATIONS
OPERATION
FUNCTION
Fundamental
PATCHING
Summer O p e r a t i o n
Eo = - R f ( E 1 / R 1 + E2/R2 ... + En/Rn)
Summer
(amplifiers
1-4)
Eo = - ( A + B + I 0 C + 10D)
NO PATCHING TO SWITCH CONTROL "SW"
Summer
(amplifiers
1-4
w i t h IC networks)
Eo = - (A + B + C)
NO PATCHING TO SWITCH CONTROL "SW"
Summer
(amplifiers
5
&
6)
Eo = - ( . 1 A + .1B + .1C)
Inverter
(amplifiers
7
&
8)
Eo = -A
COMDYMA, Inc.
OPERATOR'S
MANUAL
OPERATION
FUNCTION
Fundamental
I n t e g r a t o r Operation
Integrator
(amplifiers
1-4)
Attenuator
(pots
1-6)
Eo = K ( A )
Attenuator
(pots
7
&
8)
Eo = K ( A )
Voltage D i v i d e r
(pots
7
&
8)
Eo = K(A - B) + B
PATCHING
OPERATOR'S
MANUAL
OPERATION
FUNCTION
PATCHING
Fundamental M u l t i p l i e r O p e r a t i o n
Eo
=
-(X*Y)
Multiplier
Eo =
-(A*B)
Divider
Eo =
Squarer
Square
Root
-(A/B)
A > 0
OPERATOR'S
MANUAL
PATCHING
OPERATION
FUNCTION
Fundamental
Differentiator
Operation
Eo
Ein
Differentiator
(amplifiers
Eo
1-4)
=
-RC*dEin/dt
Eo = - d A / d t
NO
SWITCH CONTROL
PATCHING
Track/Store
(amplifiers
1-4)
Eo' = -A when Q i s a l o g i c 0
Eo' = -A' when Q i s a l o g i c 1
A'
is the s t o r e d v a l u e of A
when Q s w i t c h e s f r o m 0 to 1
Eo = A ' ( n - 1 )
A'(n-1)
is the p r e v i o u s value of A'
SPDT
Electronic
Switch
(amplifiers
1-4)
Eo =
-A when Q is a L o g i c " 0 "
Eo =
-B when Q is a L o g i c " 1 "
COMDYNA, Inc.
OPERATOR'S
B . 10. 1
MANUAL
T H E M O D E L 709 V A R I A B L E D I O D E F U N C T I O N G E N E R A T O R
T h e M o d e l 709 V D F G i s p r o g r a m m e d a s a n i n p u t n e t w o r k .
For operation, it must be conn e c t e d t o the s u m m i n g j u n c t i o n o f a n o p e r a t i o n a l a m p l i f i e r .
W h e n the f e e d b a c k o f t h i s
a m p l i f i e r i s a r e s i s t o r , s u c h a s s h o w n i n F i g . B . 10. 1 - 1 , t h e V D F G f u n c t i o n a p p e a r s a s i t s
output.
F i g . B . 10. 1-1
Input X
Positive Reference
Negative Reference
The f o l l o w i n g p r o c e d u r e s m a y be used f o r s e t t i n g f u n c t i o n s :
1.
C o n s t r u c t a n o u t p u t / i n p u t p l o t o f the f u n c t i o n t o b e s e t .
The c u r v e should be d r a w n on
g r a p h paper w i t h f u l l scale c o - o r d i n a t e s r e l a t i n g to c o m p u t e r r e f e r e n c e .
The best
s t r a i g h t l i n e a p p r o x i m a t i o n t o the c u r v e s h o u l d t h e n b e d e t e r m i n e d .
These s t r a i g h t
l i n e s w i l l e s t a b l i s h the b r e a k p o i n t l o c a t i o n s .
E l e v e n s e g m e n t s a r e a v a i l a b l e w i t h the
709 n e t w o r k .
A c e n t e r s e g m e n t g e n e r a t e s the f u n c t i o n s l o p e a t t h e X a x i s o r i g i n .
F i v e s e g m e n t s a r e l o c a t e d o n e i t h e r s i d e o f the o r i g i n .
T h e i n t e r s e c t i o n o f the c e n t e r
s e g m e n t w i t h the f i r s t s e g m e n t o f t h e p o s i t i v e side i s the f i r s t p o s i t i v e b r e a k p o i n t .
T h e i n t e r s e c t i o n o f the f i r s t a n d second s e g m e n t i s the s e c o n d p o s i t i v e b r e a k p o i n t , e t c .
Negative b r e a k p o i n t s a r e s i m i l a r l y n u m b e r e d on t h e negative side of the o r i g i n .
The
i n t e r s e c t i o n o f the c e n t e r s e g m e n t w i t h t h e Y a x i s e s t a b l i s h e s t h e p a r a l l a x .
F o r an
e x a m p l e o f the p a r a l l a x , c e n t e r s l o p e a n d t w o p o s i t i v e a n d n e g a t i v e b r e a k p o i n t s , see
F i g . B . 10. 1-2.
2.
C o n n e c t c o m p u t e r r e f e r e n c e t o the " + " a n d " - " j a c k s f o u n d o n the V D F G p a n e l .
t h e V D F G t o a n a m p l i f i e r a s s h o w n i n F i g . B . 10. 1 - 1 .
3.
C o n n e c t a r a m p t h a t s w e e p s f r o m n e g a t i v e t o p o s i t i v e r e f e r e n c e a s the V D F G i n p u t .
4.
Set u p i s e a s i e s t w h e n the c o m p u t e r i s i n t h e r e p e t i t i v e o p e r a t i o n m o d e and t h e f u n c t i o n
is displayed on an oscilloscope.
S e t t i n g i n the s l o w t i m e m o d e m a y b e d e s i r e d , h o w e v e r , because of the i n c r e a s e d a c c u r a c y o f f e r e d by an XY p l o t t e r r e a d o u t .
In either
c a s e , d i s p l a y t h e V D F G a m p l i f i e r o u t p u t a s a f u n c t i o n of t h e i n p u t . T h e V D F G w i l l
t h e n b e set t o d u p l i c a t e t h e c u r v e d r a w n i n s t e p 1 a b o v e .
Patch
OPERATOR'S
MANUAL
5.
T u r n a l l the p o s i t i v e b r e a k p o i n t a d j u s t m e n t s t o t h e i r c l o c k w i s e s t o p s .
T u r n a l l the
negative breakpoint adjustments t o t h e i r counterclockwise stops.
A l l breakpoints w i l l
t h e n b e r e m o v e d t o t h e i r f a r t h e s t p o s i t i o n f r o m the o r i g i n .
6.
T u r n the P a r a l l a x f o r the d e s i r e d i n t e r s e c t i o n a t the Y a x i s .
7.
Set the
8.
T u r n e i t h e r the f i r s t n e g a t i v e o r the f i r s t p o s i t i v e b r e a k p o i n t a d j u s t m e n t t o t h e d e s i r e d
first breakpoint location.
T r i m the f i r s t slope a d j u s t m e n t f o r the d e s i r e d f i r s t segment
slope.
R e p e a t t h i s p r o c e d u r e f o r a l l t h e b r e a k p o i n t a n d slope a d j u s t m e n t s .
Always
m a k e a d j u s t m e n t s i n a sequence f r o m the o r i g i n .
9.
R e p l a c e the r a m p w i t h the d e s i r e d p r o g r a m i n p u t .
" C T R S L O P E " a d j u s t m e n t f o r the d e s i r e d c e n t e r s e g m e n t s l o p e .
P l e a s e note t h a t t h e g e n e r a t e d f u n c t i o n , i . e . i n d i v i d u a l s e g m e n t s l o p e s , w i l l v a r y p r o p o r t i o n a l l y w i t h the a m p l i f i e r f e e d b a c k r e s i s t o r .
The range of i n d i v i d u a l segment slopes may,
t h e r e f o r e , be i n c r e a s e d by r a i s i n g the value of t h i s r e s i s t o r .
O r , slopes m a y be increased
b y p l a c i n g a c o e f f i c i e n t a t t e n u a t o r i n s e r i e s w i t h the f e e d b a c k r e s i s t o r .
I n t h i s c a s e , the
slope r a n g e i s i n c r e a s e d b y t h e r e c i p r o c a l o f the p o t e n t i o m e t e r s e t t i n g .
OPERATOR'S MANUAL
MODEL 771 TRANSFER FUNCTION SIMULATOR
GENERAL DESCRIPTION
The 771 p r o v i d e s a n a n a l o g c o m p u t e r s i m u l a t i o n o f e i g h t b a s i c t r a n s f e r f u n c t i o n s .
Each h a s t h r e e s e t s o f p a r a m e t e r s .
The e i g h t t r a n s f e r f u n c t i o n s a n d t h e i r a s s o c i a t e d
parameter values are o u t l i n e d in Table 1.
The 771 o u t p u t i s t h e t r a n s f e r f u n c t i o n
r e s p o n s e t o any p a t c h e d a n a l o g i n p u t , s u c h a s a s i n e wave, s q u a r e wave, p u l s e , e t c .
I t a l s o f e a t u r e s a r e s e t mode c o n t r o l t o s y n c h r o n i z e i t s u s e w i t h r e p e t i t i v e o p e r a t i o n
analog computers o r o t h e r s i m i l a r systems.
OPERATING INSTRUCTIONS
p o w e r . . . T h e 7 7 1 has a s e l f c o n t a i n e d p o w e r s u p p l y f o r u s e w i t h a n y 110 v o l t o u t l e t .
F u n c t i o n S e l e c t i o n . . . A t r a n s f e r f u n c t i o n and i t s p a r a m e t e r s e t i s d e t e r m i n e d b y two
Selector switches.
T o s e l e c t t r a n s f e r f u n c t i o n G ( s ) p a r a m e t e r s e t A , f o r example,
t u r n t h e r i g h t hand s w i t c h t o G ( s ) a n d t h e l e f t hand s w i t c h t o "A."
3
3
O p e r a t i o n w i t h E x t e r n a l E q u i p m e n t . . . A common g r o u n d c o n n e c t i o n i s a l l t h a t i s needed
t o c o n n e c t t h e 7 7 1 t o an e x t e r n a l s y s t e m . The maximum v o l t a g e i n p u t i s p l u s - m i n u s 10
v o l t s . The r a t e d o u t p u t v o l t a g e i s p l u s - m i n u s 10 v o l t s . O u t p u t c u r r e n t i s a minimum
5 mas a t p l u s o r minus 1 0 v o l t s .
Mode C o n t r o l . . . A l o g i c 0 ( 0 o r p o s i t i v e v o l t s ) p a t c h e d t o t h e "MODE CTL" j a c k w i l l
r e s e t the t r a n s f e r f u n c t i o n to a zero o u t p u t .
The absence o f p a t c h i n g o r a l o g i c 1
(-2 o r more n e g a t i v e v o l t s ) w i l l p l a c e t h e u n i t i n t o a n o r m a l o p e r a t i n g mode.
O p e r a t i o n w i t h t h e GP-6 A n a l o g C o m p u t e r . . . For
p a t c h c o m p u t e r g r o u n d t o t h e 771 "GND" j a c k .
771 "MODE CTL" j a c k .
o p e r a t i o n w i t h t h e GP-6 a n a l o g c o m p u t e r ,
P a t c h t h e c o m p u t e r "OP" t e r m i n a l t o t h e
lime Constants... T r a n s f e r f u n c t i o n time c o n s t a n t s are g i v e n i n Table 1 both i n r e f e r ence t o t h e GP-6 p r o g r a m s e c o n d s and r e a l t i m e .
The GP-6 p r o g r a m s e c o n d s a r e f o r t h e
r e p e t i t i v e o p e r a t i o n time scale.
O p e r a t i o n w i t h O t h e r C o m p u t e r s . . . T h e r e p e t i t i v e o p e r a t i o n mode c o n t r o l o p e r a t i n g
l e v e l s s h o u l d be c h e c k e d . I f a 0 o r p o s i t i v e v o l t l e v e l i s t h e c o m p u t e r ' s i n i t i a l
c o n d i t i o n mode l o g i c and a -2 t o -15 v o l t l e v e l i s t h e o p e r a t e mode l o g i c , t h e n t h e
c o m p u t e r ' s mode c o n t r o l bus may be c o n n e c t e d t o t h e 771 "MODE CTL" j a c k . O t h e r w i s e a
l e v e l c h a n g e r must b e i n c l u d e d a s a b u f f e r between t h e two u n i t s .
Circuit
D e s c r i p t i o n . . . T r a n s f e r f u n c t i o n s a r e s i m u l a t e d t h r o u g h t h e a p p l i c a t i o n o f two
o p e r a t i o n a l a m p l i f i e r s and p a s s i v e R-C n e t w o r k s .
Each a m p l i f i e r has a s e l e c t i o n o f
eight networks.
The two a m p l i f i e r s o p e r a t e i n s e r i e s .
The t r a n s f e r f u n c t i o n s e l e c t o r
s w i t c h has two p o l e s t h a t p r o g r a m t h e a m p l i f i e r s b y c o n n e c t i n g a n e t w o r k t o each o f
t h e summing j u n c t i o n s .
An i n p u t t h u s passes t h r o u g h a n e t w o r k to a m p l i f i e r 1; the
o u t p u t o f a m p l i f i e r 1 passes t h r o u g h a n e t w o r k t o a m p l i f i e r 2 ; t h e o u t p u t o f a m p l i f i e r
2 is the t r a n s f e r f u n c t i o n output.
The p a r a m e t e r s e l e c t o r s w i t c h a l t e r s a n e t w o r k ' s
p a r a m e t e r s b u t does n o t change i t s b a s i c c h a r a c t e r i s t i c s . Each o f t h e two a m p l i f i e r s
have an e l e c t r o