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© National Instruments
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2-37
Adding Components for Attenuating Voltage on Analog
Input Signals
You can build a two- or three-resistor circuit for attenuating voltages at the single-ended analog
inputs and differential analog inputs of the SCB-68A:
•
Differential analog input attenuators
—To build a three-resistor circuit for attenuating
voltages at the differential analog inputs of the SCB-68A, refer to Figure 2-36. Refer to
Table 2-1 for component positions for all analog input channels.
The SCB-68A ships with a surface mount 0
Ω
resistor in the F and G positions. You
must
remove the resistors to use these positions.
Figure 2-36.
SCB-68A Circuit Diagram for Differential Analog Input Attenuation
Install resistors in positions E, F, and G of the chosen differential channel pair. Use the
following equation to determine the gain of the circuit:
•
Single-ended analog input attenuators
—To build a two-resistor circuit for attenuating
voltages at the single-ended analog inputs of the SCB-68A, refer to Figure 2-37. Refer to
Table 2-1 for component positions for all analog input channels.
The SCB-68A ships with a surface mount 0
Ω
resistor in the F and G positions. You
must
remove the resistor to use the position.
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+
8
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S
C
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E
A
F
G
B
C
D
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+
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+ 5 V
AI GND
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+
8
G
R
E
R
E
R
F
R
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(
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