GE DS3800NVOC

Key Parameters

• Input Signal: 0–10V DC or 4–20mA (jumper-selectable) from VME backplane

• Output Type: High-current analog ±10V / ±50mA or 4–20mA (configurable per channel)

• Channels: 4 independent output channels with individual gain/offset trims

• Drive Capability: Up to ±50mA continuous per channel (sufficient for most EHC servo valves)

• Diagnostics: Output short-circuit protection, open-loop detection, over-temperature shutdown

• Temp Range: –30°C to +70°C

• Power Supply: +5V, ±15V from backplane

• Physical: 6U VME single-slot board

Advantages

• High-current drive – directly powers EHC torque motors without external amplifiers.

• Isolated outputs – each channel is galvanically isolated from the backplane logic, preventing ground loops.

• Adjustable gain/offset – fine-tune valve response without changing software parameters.

• Short-circuit protection – automatic current limiting prevents damage to the DS3800NVOC and downstream servo valves.

• Quick swap – field-replaceable without recalibrating the entire loop (plug-and-play with stored trim pots).

Applications

• Gas turbine fuel control – drives the main fuel servo valve for gas or liquid fuel.

• Steam turbine EHC – positions intercept, stop, and control valves.

• Inlet guide vanes (IGV) – modulates IGV position for compressor surge prevention.

• Bypass and dump valves – provides rapid response for emergency shutdown sequences.

vs Competitors & Related Variants

Selection Tips

• Valve matching – verify your EHC servo valve requires ±50mA or less; the DS3800NVOC cannot drive larger proportional valves directly (use an interposing amplifier).

• Input mapping – confirm your main processor is configured to send the correct channel assignment to the General Electric DS3800NVOC.

• Spare strategy – keep one DS3800NVOC per 5 installed units; valve short circuits can damage the output stage.

• Calibration – record the trim pot settings (gain/offset) for each channel before removal; use a precision multimeter during re-installation.

Critical Precautions

• Output short – never short output terminals while powered; the DS3800NVOC has foldback protection but repeated shorts can degrade accuracy.

• Grounding – ensure the servo valve shield is grounded only at the DS3800NVOC end to avoid ground loops.

• Power sequencing – apply backplane power only after all output cables are securely connected; disconnecting under load can cause voltage spikes.

• Potentiometer handling – adjust gain/offset trims slowly; over-torquing can damage internal wipers.

• Heat dissipation – the DS3800NVOC generates significant heat at high output currents; ensure adequate airflow (>200 CFM) across the board.

• Compatibility – do not mix the DS3800NVOC with older Mark I–III I/O racks; it is specifically designed for Mark IV VME backplanes only.