Quick Sizing & Sourcing Snapshot
- Manufacturer: General Electric (GE)
- Part Number: DS200TCQCG1BHF
- System Platform: GE Speedtronic Mark V (TMR/Simplex)
- Hardware Type: TCQC (Temperature, Current, Quadrature, Analog) Core I/O Board
- Architectural Role: Resides in the R, S, or T Core of the Mark V rack; processes LVDT position feedback, 4-20mA analog signals, Thermocouples, and servo valve drive outputs for turbine control.
- Key Specifications: Signal Handling: LVDT Demodulation, 4-20mA I/O, TC Linearization; Configuration: Hardware Jumpers (J1-J6); Interface: 3PL (Corebus), JF (LVDT), JE (Servo), JZ (TC).
System Architecture & Operational Principle
The is a workhorse of the Mark V architecture, occupying the dedicated “QC” slot (usually Slot 7 or 8) in the R, S, and T core processors. Unlike the distributed I/O of Mark VIe, this is centralized processing. It connects to the Corebus via the 3PL connector, receiving synchronized data from the STCA (Turbine Control) boards and sending back processed analog data (like exhaust temps or vibration).
Its primary job splits into two distinct paths: Inputs and Outputs. On the input side, it handles the tricky business of LVDT (Linear Variable Differential Transformer) demodulation via the JF connector. It generates the excitation frequency (usually 2400 Hz or 4800 Hz, jumper-set) and decodes the secondary voltages to determine valve stem position (e.g., Gas Control Valve or Inlet Guide Vanes). It also scales 4-20mA inputs (from pressure transmitters) and conditions Thermocouple inputs (with cold junction comp via the JZ link to the TCQA).
On the output side (JE Connector), it drives Servo Valves. It takes the digital demand from the <TCEA> algorithm in the STCA, converts it to an analog current (typically 0-200mA range, jumper selected via J5/J6), and pushes it to the Moog or Abex servo drivers. The “BHF” suffix indicates a specific Bill of Materials revision (likely involving capacitor upgrades or trace shielding modifications for noise immunity compared to earlier “B” or “BHH” revisions), but it remains pin-for-pin and jumper-for-jumper compatible with the base G1B design.
Core Technical Specifications
- Board Type: TCQC (Temp, Current, Quadrature, Control)
- Connectors: 3PL (Corebus), JE (Servo I/O), JF (LVDT), JG (Analog I/O), JZ (TC Ref)
- LVDT Excitation: Jumper selectable (2400 Hz / 4800 Hz / 60 Hz)
- Analog Ranges: 4-20mA, 0-20mA, 0-10V, +/- 10V (Set by J1, J2, J5, J6)
- Servo Drive Capacity: Up to 200mA (typical), short-circuit protected
- Thermocouple Type: J, K, E, T, S, R (Software selectable, hardware filtered)
- Isolation: Optical isolation on critical I/O channels from logic
- Power: +5V, +/-15V from Rack Backplane
- Physical: 9.0 x 6.5 inches (Standard Mark V PCB), Edge Card Fingers
