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OPERATOR'S
&
MAINTENANCE M A N U A L - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
page A1
982/983 DUAL MULTIPLIER NETWORKS
The 982.2/983 board assemblies provide two independent multiplier networks, configured so that each, when used
with an external operational amplifier may be programmed as a multiplier, divider, squarer or square root extractor.
Two inputs (Xin and Yin) are multiplied by integrated circuit M to produce a voltage proportional to the product
X*Y.
The voltage is converted to a current by resistor RS, scaled so that when connected to the summing junction of
a patch panel amplifier, and where the feedback is a standard
gain
1 SOK ohm resistor, the amplifier will produce a
full scale 10 volts output with 10 volts as the X and Y inputs.
Adjustments
Each network is orginally adjusted at the factory. The networks should, however, be checked and readjusted, if
necessary, during the initial checkout. Thereafter, the networks should be periodically checked to assure their most
accurate operation. About 10 to 20 minutes should be allowed for warm-up before adjusting.
Adjustment consists of zero offset balancing (model 783 only) and a trim for gain and linearity. The suggested
procedures are as follows:
1.
Program the network as a multiplier.
2.
With inputs X and Y patched to ground, adjust potentiometer Pz for a zero output. Disregard for the
982.2 network.
3.
Program an integrator as a ramp function to sweep from minus to plus 1
o
volts reference. (For
convenience make all adjustments in the repetitive operation mode.) Display the multiplier output vs.
the ramp input.
Patch the ramp to the Y input; the X input should remain patched to ground. Adjust
potentiometer Px until a best zero curve is obtained.
4.
Reverse the X and Y inputs. Adjust potentiometer Py until a best zero error is obtained.
5.
Readjust Pz if necessary.
6.
Patch Reference (
+
or-) to the X input and the ramp to the Y input. Sum the product with the correct
polarity of the ramp to display an error curve. Adjust potentiometer Pg until a best error curve is obtained.
Reverse the X and Y inputs, recheck and readjust if necessary. Check the error curve with the opposite
polarity Reference input and reverse inputs as done with the original polarity. Trim potentiometer Pg
until a best compromise of error curves is obtained for all four input combinations.
982.2 DUAL MULTIPLIER NETWORK
Assembly Drawing
-,cc::,-,-oc::>C:-U
<.n·-·""l()(I) c:·,..,l()·,..,
C
_j>-X-~l?>-..-,Xl:J
_J_J+
a:~10::a:
Schematic
8litt
XI
+vs
p
X2
w
Vt
M
z
V2
-Vs
11111n
+15V
SJ
•1!5U
'l'in
Parts List
R6
100
R3,R4
1
K
RS
49.9
K
Rl,R3
330
K
Px,Py
50
K
Pg
500
Cl
33
pf
C2,C3
.1
uf
M
A0633JN
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - C O M DYNA, INC.
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