3B42 / 3B43 / 3B44

Rev. 0 | Page 2 of 8

GENERAL DESCRIPTION

The 3B42, 3B43, and 3B44 are single-channel AC sine wave

signal conditioning modules which use an AC averaging

technique to rectify, amplify, and filter 50 Hz to 400 Hz sine-

wave signals ranging from 20 mV to 550 V rms to give an rms

output reading. Simultaneous precision voltage and current

outputs are provided including isolation (+1500 V peak input-

to-output and power). The 3B42 and 3B43 modules withstand

220 V rms, and Model 3B44 withstands 550 V rms at its input

terminals without damage, thereby shielding computer-side

circuitry from field-side over-voltage conditions. Each plug-in,

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

via front-panel zero and span adjustments for both voltage and

current outputs.

3B Series Custom-Ranging Program – Externally-

programmable versions, Models 3B42-00, 3B43-00, and 3B44-

00, enable the user to configure a special input range 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.

Signal isolation by transformer coupling uses a proprietary

modulation technique for linear, stable and reliable

performance. The differential input circuit on the field side is

fully floating, eliminating the need for any input grounding. A

demodulator on the computer side of the signal transformer

recovers the original signal, which is then filtered and buffered

to provide a low-noise, low-impedance output signal.

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Figure 2