Soldering And Desoldering On The Bnc-2090A; Installing Bias Resistors - National Instruments BNC-2090A User Manual

Soldering and Desoldering on the BNC-2090A

Caution Use a low-wattage (20 to 30 W) soldering iron when soldering to the device. You
should use only rosin-core, electronic-grade solder. Acid-core solder damages the printed
circuit device and components. Use vacuum-type tools when desoldering on the
BNC-2090A to avoid damaging component pads.
This product is RoHS-compliant. If you require that the product remain
Note
RoHS-compliant, ensure that you use RoHS-compliant solder and components.
Visit
ni.com/rohs

Installing Bias Resistors

© National Instruments Corporation
2. Remove the two front panel screws.
3. Hold the front panel and slide the unit out of the metal case.
4. Install and/or remove components as necessary. Refer to the Soldering
and Desoldering on the BNC-2090A section for more information.
5. Reassemble the BNC-2090A in reverse order.
Some applications require you to modify the PWB, usually by removing
0 Ω jumpers and adding components. The BNC-2090A is shipped with 0 Ω
jumpers in the C and D positions, as listed in Table 3-1 and shown in
Figure 3-1.
for more information.
You can install bias resistors in positions A and B on the BNC-2090A, as
listed in Table 3-1 and shown in Figure 3-1. Refer to the steps in the
Signal Conditioning Components
the resistors on the BNC-2090A.
Figure 3-15 shows both the schematic and the component placement for a
single 100 kΩ bias return resistor on the negative input from a floating
source connected to channel 1, the B position in Table 3-1. Refer to the
Analog Input Signal Conditioning
additional signal conditioning circuitry, such as filters and attenuators, in
the open component positions.
section for instructions about accessing
section for information about building
3-15
Chapter 3 Signal Conditioning
Adding
BNC-2090A User Manual