Description
DS3800HCVA1G1F: Product Overview
The DS3800HCVA1G1F is a daughterboard-grade D/A converter that occupies a 6BA09 slot in the GE Speedtronic Mark IV rack. It receives parallel digital words (speed demand, temperature bias, load set-point) from the CPU over the VME back-plane, converts them to precise analog voltages or currents, and drives servo amplifiers, IGV positioners, and remote indicators throughout the turbine island. The card is hardware-configurable (no firmware) and deterministic, making it suitable for safety-related control loops when triple-redundant.
Physical implementation includes 12-bit DACs, op-amp output stages, galvanic isolation, and TVS surge suppressors. 37 gold-pinned jumpers select output range (±10 V, 0–10 V, 4–20 mA), update rate, and channel enable masks. 20-pin ribbon carries analog outputs to the carrier motherboard; 1500 V AC opto-isolation breaks ground loops between turbine deck and control room. Front-edge LEDs (red/green) per channel give real-time output health—no multimeter required during commissioning.
Environmental qualification meets IEEE 344 Class 1 (seismic) and –40 °C to +85 °C operation, permitting installation directly on the turbine deck with no extra HVAC. MTBF is >300 000 h at 55 °C, giving >25-year service life in baseload duty.
DS3800NISB1F1E
DS3800HCVA1G1F: Technical Specifications
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Model Number: DS3800HCVA1G1F
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Manufacturer: General Electric (GE Energy)
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Product Type: Digital-to-Analog Output Board (DAC)
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Resolution: 12-bit monotonic, ±½ LSB integral non-linearity
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Output Ranges: ±10 V, 0–10 V, 4–20 mA (jumper-selectable per channel)
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Settling Time: <5 µs to ±0.1 % for 10 V step
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Load Capability: 5 mA (voltage mode), 750 Ω (current mode)
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Isolation: 1500 V AC channel-to-ground, 500 V channel-to-channel
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Update Rate: 100 kHz max (jumper-selectable 1 kHz, 10 kHz, 100 kHz)
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Trimmers: Offset and gain pots per channel (front-access)
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Connectors: 20-pin ribbon, keyed, gold-plated
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Power Rails: +5 V DC logic, ±15 V DC analog, <1 W per channel
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LEDs: Green = output active, Red = over-range / fault
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Temp Range: -40 °C to +85 °C operational, -55 °C to +125 °C storage
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Vibration / Shock: 15 g continuous, 30 g shock (IEEE 344)
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Certifications: SIL2 (IEC 61508), API 670, CE industrial emissions
Core Features & Customer Value
Microsecond-Fast Settling for Servo Loops
<5 µs settling to 0.1 % enables 10 kHz servo-loop bandwidth—critical for IGV positioners and fuel-metering servo valves that must track speed/load transients without overshoot.
<5 µs settling to 0.1 % enables 10 kHz servo-loop bandwidth—critical for IGV positioners and fuel-metering servo valves that must track speed/load transients without overshoot.
Hot-Swappable in TMR Strings
Redundant Mark IV allows online replacement of one DAC card; remaining two legs continue voting. MTTR is <5 min—no outage, no load shed, no restart required.
Redundant Mark IV allows online replacement of one DAC card; remaining two legs continue voting. MTTR is <5 min—no outage, no load shed, no restart required.
Field-Calibrated Without Software
Offset and gain trimmers compensate for valve hysteresis, cable resistance, or amplifier drift—technician can trim full-scale and zero using only a screwdriver and a DMM, reducing commissioning time by >50 %.
Offset and gain trimmers compensate for valve hysteresis, cable resistance, or amplifier drift—technician can trim full-scale and zero using only a screwdriver and a DMM, reducing commissioning time by >50 %.
Surge-Hardened for Turbine Deck
TVS diodes and opto-isolators clamp >500 V spikes from servo amplifiers or lightning. 1500 V isolation prevents ground-fault propagation to CPU cards, reducing cascade failures by >60 % compared with non-isolated DACs.
TVS diodes and opto-isolators clamp >500 V spikes from servo amplifiers or lightning. 1500 V isolation prevents ground-fault propagation to CPU cards, reducing cascade failures by >60 % compared with non-isolated DACs.
GE DS3800HRDA1C1B
Typical Applications
Gas Turbine Fuel & IGV Control
Drives ±10 V input to Woodward servo amplifiers for fuel-metering valves and IGV hydraulic actuators in Frame 7/9 units. 12-bit resolution achieves 0.025 % fuel-flow accuracy, essential for NOx compliance and part-load heat-rate optimization.
Drives ±10 V input to Woodward servo amplifiers for fuel-metering valves and IGV hydraulic actuators in Frame 7/9 units. 12-bit resolution achieves 0.025 % fuel-flow accuracy, essential for NOx compliance and part-load heat-rate optimization.
Steam Turbine Governor & Extraction Control
4–20 mA output drives Moog servo valves on governor and extraction pressure loops. Deterministic update rate prevents valve dither and mechanical wear, extending servo life to >100 k hours.
4–20 mA output drives Moog servo valves on governor and extraction pressure loops. Deterministic update rate prevents valve dither and mechanical wear, extending servo life to >100 k hours.
Remote Indication & DCS Interface
0–10 V scaled signals feed plant DCS for remote load meters, temperature indicators, and vibration displays. Isolation eliminates ground-loop noise that would corrupt 4–20 mA loops in large combined-cycle sites .
0–10 V scaled signals feed plant DCS for remote load meters, temperature indicators, and vibration displays. Isolation eliminates ground-loop noise that would corrupt 4–20 mA loops in large combined-cycle sites .
