3B20

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GENERAL DESCRIPTION

The 3B20 is a wideband single-channel signal-conditioning

module which interfaces 4-arm AC bridge transducer signals

ranging between 1.5mV rms and 150mV rms, providing

simultaneous precision voltage and current outputs. In addition,

the module provides an AC excitation voltage of 2V rms to 10V

rms at frequencies between 1kHz and 10kHz. The module

withstands 130V rms at its current output terminals without

damage thereby shielding computer-side circuitry from field-

side over-voltage conditions. The 3B20 is a plug-in, mix-and-

match, hot-swappable module and is easily field calibrated via

front-panel zero and span adjustments for both voltage and

current outputs.

3B Series Custom-Ranging Program – Externally-

programmable Model 3B20-00, enables the user to configure a

special input range, including tare weight suppression, by using

the optional plug-on AC1310 ranging card, which houses user-

supplied resistors to determine zero and span. To facilitate

selecting resistors, a Windows program, 3B-CUSTOM,

calculates resistor values based on the user-desired input/output

ranges.

The 3B20 input and AC bridge excitation output terminals are

protected for up to 130V rms. The excitation amplitude and

frequency can be specified with the Model 3B20 CUSTOM or

user configured with Model 3B20-00 and an optional plug-on

Model AC1310 ranging card. Both the voltage and current

outputs can be independently adjusted for a minimum of +1V

for the zero and 25% of the span range with front-panel user-

accessible potentiometers. In addition, phase shifts of up to

strain gauge or torque transducer can be compensated via front-

panel screw terminal adjustments.

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Figure 2