Hytec Electronics Ltd.

Data Acquisition and Control

VDB8914 DIN Rail Mounted Octal LVDT Interface Terminal Board 

Product Description

The VD 8914 is a DIN Rail mounted terminal block which can be used to connect a number of  LVDTs to an ADC 8401 via a TB9202 transition board using a SCSI 50-way cable.The unit conditions and accepts the outputs from up to eight LVDT sensors, with primary excitation provided by low distortion on-board sine wave oscillators.

The circuitry uses a ratiometric approach to eliminate several of the disadvantages associated with traditional LVDT measurement. Voltage output is given by the equation Vout=Iref*(Va-Vb)/(Va+Vb)*R where R is an on-board resistor value. There are a total of 40 terminals for connection of the LVDTs. In each group, two terminals are used for the primary excitation connections and three for the secondary voltage measurement.  LVDTs may be located at a distance of up to 100 metres.

Temperature Range 0 to 50 deg C

Power Supply 24V @1A from external PSU (e.g. DIN rail mounted PSU) (On-board DC-DC converter generates +/-15V)

Signal Inputs
Voltage: 0.1 to 3.5V rms
Impedance: 200kohms
Bias current: 5uA max.

Signal Outputs
Voltage: +/-10V d.c. full scale
Current: 6mA
Non-linearity: 75ppm of FS typical over the temperature range.
Gain error: +/-1% of FS max.
Offset: +/-1% of FS max.
Gain drift: 20ppm per deg C typical
Offset drift: 7ppm per deg C typical

Excitation Outputs
Voltage: 2.1V to 24Vrms by resistor selection
Current: 30mA rms typical
Frequency: 10Hz to 20kHz (programmed by on-board capacitor to 2.4kHz)
Gain error: +/-1% of FS max.
Offset: +/-100mV max
Voltage drift: 600ppm per deg C typical
Frequency drift: 7ppm per deg C typical

SCSI   
50 way connection to Transition Board 8304, or SCB9202 for use with an 9010 IOC or Transition Board 8307/8308

Download VDB8914 User Manual