34
Magtrol Model 6530 Three-Phase Power Analyzer
Chapter 4 – Operating Principles
THEOR
Y
4.1.3
E
XTERNAL
S
HUNT
The external shunt signal is brought in through a precision voltage divider of 9.1 k and 9.1 k resistors.
The gain is 0.50. This signal is buffered and passed into a programmable gain section. The gains for
the voltage ranges are given below.
e
g
n
a
R
s
r
o
t
s
i
s
e
R
)
r
e
i
f
i
l
p
m
A
(
n
i
a
G
V
m
0
5
0
2
6
/
k
2
1
0
5
3
.
9
1
-
V
m
0
5
2
0
2
6
/
k
4
.
2
1
7
8
.
3
-
V
m
0
0
5
0
2
6
/
k
2
.
1
6
3
9
.
1
-
V
m
0
0
0
1
0
2
6
/
0
2
6
0
0
0
.
1
-
The signal is then presented to an AD7722AS 16-bit analog to digital converter. The part accepts an
input signal of +/- 1.25 volts centered on a 2.5 VDC volt bias. The chart below shows system input
at 10% and 100% of range.
e
g
n
a
R
)
C
D
V
(
n
I
s
t
l
o
V
)
l
a
t
o
t
(
n
i
a
G
t
u
p
n
I
D
/
A
t
a
s
t
l
o
V
s
t
i
B
V
m
0
5
5
0
0
.
0
0
0
5
7
6
.
9
-
4
8
4
0
.
0
-
8
6
2
1
V
m
0
5
0
5
0
.
0
0
0
5
7
6
.
9
-
8
3
8
4
.
0
-
1
8
6
2
1
V
m
0
5
2
5
2
0
.
0
0
5
5
3
9
.
1
-
4
8
4
0
.
0
-
8
6
2
1
V
m
0
5
2
0
5
2
.
0
0
5
5
3
9
.
1
-
9
3
8
4
.
0
-
4
8
6
2
1
V
m
0
0
5
0
5
0
.
0
0
0
8
6
9
.
0
-
4
8
4
0
.
0
-
9
6
2
1
V
m
0
0
5
0
0
5
.
0
0
0
8
6
9
.
0
-
0
4
8
4
.
0
-
8
8
6
2
1
V
m
0
0
0
1
0
0
1
.
0
0
0
0
0
5
.
0
-
0
0
5
0
.
0
-
1
1
3
1
V
m
0
0
0
1
0
0
0
.
1
0
0
0
0
5
.
0
-
0
0
0
5
.
0
-
7
0
1
3
1
:
n
o
i
t
u
l
o
s
e
R
r
e
t
r
e
v
n
o
C
7
9
6
4
1
8
3
0
0
0
0
.
0
=
6
3
5
5
6
/
5
.
2
=
6
1
^
2
/
5
.
2
4.2
DIGITAL PROCESSING
Starting at the AD7722AS analog to digital converter, the input clock to the device is 14.31818
MHz. This clock frequency gives a sample rate or data output rate of 14318180 / 64 = 223721.5625
samples per second.
The DSP processor uses fractional data representation for all Data ALU operations. Using long
words (48-bit) the most negative number that can be represented is -1 ($800000000000). The most
positive number that can be represented is 1 – 2
-47
($7FFFFFFFFFFF).
Example:
$123456 (Hex integer)
0001 0010 0011 0100 0101 0110 (Binary)
0.142222166 (Fractional)
