3 full bridge and half bridge input mode, Full bridge and half bridge input mode, Figure 3-4 – ADLINK USB-2401 User Manual

Page 40: Current source connection

Operation

Figure 3-4: Current Source Connection

3.3.3

Full Bridge and Half Bridge Input Mode

A bridge-based transducer is a passive device, requiring voltage
excitation to convert the resistive change to an electrical signal.
The USB-2401 provides a steady 2.5V excitation voltage for each
analog input channel in full bridge and half bridge modes. For
half-bridge transducer, USB-2401 has built-in precision 20kΩ
resistors to compensate the circuit as a full-bridge transducer
measurement.

Also provided is a moving average function, a common and useful
digital filtering method of smoothing fluctuation caused by noise.
The averaging number for data can be set to 0, 2, 4, 8, or 16,
where 0 represents disabling the moving average function.

A typical four-wire connection is shown.

NOTE:

A dotted line represents the connection and circuit of full-bridge
mode.