Fluke 8050A Instruction Manual page 37

THEORY OF OPERATION
CIRCUIT DESCRIPTION
A.AUTOZERO
U1BB C9
CM
r- - - -
-OVERRANGE
(OL)
C9
>-
~~COMPARATOR
OFFSET VOLTAGES
AND BIAS FOR BUFFER
AND INTEGRATOR
_ INTEGRATOR
R39
AZ
BUFFER
+
C7
B. INTEGRATE
SELECTABLE
GAIN
CIRCUIT
r----+-o-1)-+------I>I+ BUFFER R39
>--~::>-"O-+--------fI'l+
V,rnA
REFERENCE
VOLTAGE
(1V,VRll
SELECTABLE
GAIN
CIRCUIT
INTEGRATE
INPUT
FROM
SIGNAL
CONDITIONERS
kn,S
REFERENCE
VOLTAGE
~
(INPUT
DIVIDER) killS
..........c::>-+-o--e:J+---,
1...-_ _
X~1:.::0~
LO
...... ~X.:..1_l0
C9
I
I
I
DE (-R) IDE-R)
I
I .....- - - - - - - -
I
yo .......
"!o.
/1 DE I+R) DE(+R)
1'\
I~~_?~\
(~+
\
\ UWA UWB )
,
/
.......
--------_/
...----1+ BUFFER
U18C
RANGE AND
C. READ [DE(-R)] FOR POSITIVE UNKNOWN INPUTS
FUNCTION SWITCHES /:: - - - OVER RANGE
(Ol)
kn,s
REFERENCE
VOLTAGE
Figure
3-2.
AID Converter
3-4