3B40

The 3B40 and 3B41 are wide-bandwidth (10kHz) singlechannel signal conditioning modules which amplify, isolate, filter and protect analog input voltages and provide simultaneous precision voltage and current outputs. Each module performs complete signal conditioning, including isolating (+1500 V peak input-to-output and power) and protecting their computer side outputs from damage and loss of signal integrity, and shielding their inputs from damage from field-side over-voltage faults up to 220 V rms. The current output withstands 130V rms without damage and interfaces user equipment through screw terminals located on the 3B Series backplane. 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 Externallyprogrammable versions, Models 3B40-00 and 3B41-00, 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.

A chopper-stabilized low-drift (+1uV/oC) input amplifier assures long-term stability. At the amplifier input, a stable, zeroscale input voltage is subtracted from the input signal to set the zero-scale value. Zero suppression can exceed 100% of the input range. This is ideal for expanded-scale applications requiring high-resolution measurement of a selected portion of an input signal. For user convenience, the zero and span can be factory configured to meet custom range needs (Models 3B40- CUSTOM and 3B41-CUSTOM) or can be externally programmed (Models 3B40-00 and 3B41-00) via user supplied resistors inserted in the optional AC1310 plug-on ranging card.Internal low-pass filtering with a 10 kHz cutoff (-3dB) is determined by a two-pole Butterworth filter.

Signal isolation is accomplished by transformer coupling with 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 voltage: this output also drives a voltage-to-current (V/I) converter to provide a simultaneous current output for interfacing versatility.