DI-5B36 Potentiometer Input Modules

0Ω to 10kΩ Input Range

Product Features

• Interfaces to Potentiometers Up to 10,000Ω
• High Level Voltage Outputs
• 1500Vrms Transformer Isolation
• ANSI/IEEE C37.90.1-1989 Transient Protection
• Input Protected to 240VAC Continuous
• 160dB CMR
• 95dB NMR at 60Hz, 90dB at 50Hz
• CSA Certified

Products in the Series

Each DI-5B36 potentiometer input module provides a single channel of potentiometer input which is filtered, isolated, amplified, and converted to a high level analog voltage output. This voltage output is logic-switch controlled, allowing these modules to share a common analog bus without the requirement of external multiplexers.

The DI-5B36 module is designed with a completely isolated computer side circuit that can be floated to ±50V from power common (pin 16). This complete isolation means that no connection is required between I/O common and power common for proper operation of the output switch.

Excitation for the potentiometer is provided from the module by two matched current sources. When using a three-wire potentiometer, this method allows cancellation of the effects of lead resistances. The excitation currents are very small (less than 1.0mA) which minimizes self heating of the potentiometer.

Signal filtering is accomplished with a six-pole filter, which provides 95dB of normal-mode rejection at 60Hz and 90dB of rejection at 50Hz. Two poles of this filter are on the field side of the isolation barrier, and the other four are in the output stage.

After the initial field-side filtering, the input signal is chopped by a proprietary chopper circuit. Isolation is provided by transformer coupling, again using a proprietary technique to suppress transmission of common mode spikes or surges. The module is powered from +5VDC, ±5%.

A special input circuit on the DI-5B36 provides protection against accidental connection of power-line voltages up to 240VAC.