Product OverviewThe MOOG IN123-825-001 is a high-precision Servo Valve Coil and Connector Assembly manufactured by Moog Inc., a global leader in motion control technology. This specific part is a critical component of a Moog series servo valve—a high-performance electrohydraulic valve that precisely controls the flow of hydraulic fluid in response to an electrical input signal. The IN123-825-001 assembly consists of one or more torque motor coils wound on a bobbin, integrated electrical connectors (typically a Mil-Spec circular connector or a rectangular multipin type), and the associated wiring harness. It is the electromagnetic actuator portion of the servo valve, converting the control current from an amplifier into a precise mechanical force that positions the valve’s flapper or spool, thereby modulating hydraulic power to an actuator (cylinder or motor).Designed for extreme reliability in demanding aerospace, defense, and industrial applications, this coil assembly is constructed with high-temperature insulation, vacuum impregnation for moisture resistance, and robust terminations to withstand vibration and shock. Its electrical characteristics (resistance, inductance, current rating) are precisely matched to the servo valve’s performance specifications and the driving amplifier. The IN123-825-001 is a genuine Moog OEM replacement part, ensuring exact dimensional, electrical, and magnetic compatibility with the specific servo valve model it is designed for, which is crucial for restoring the valve’s original dynamic response, linearity, and stability. Failure of this coil assembly can lead to loss of control, erratic actuator motion, or complete valve failure, making it a vital spare in the maintenance of critical motion control systems.Technical SpecificationsNote: Exact specifications are proprietary to Moog and the specific valve model. The following are typical parameters for such an assembly.
Parameter Name
Likely Specification / Inference
Manufacturer / Part Number
MOOG IN123-825-001
Component Type
Servo Valve Torque Motor Coil & Connector Assembly
Compatible Valve Series
Likely fits a specific Moog valve model (e.g., in the D633, D634, D660, D680 series or similar).
Coil Configuration
Single-Coil, Dual-Coil (Push-Pull), or Center-Tapped depending on valve design.
Coil Resistance
A specific value per coil, typically in the range of 20 to 200 Ohms (e.g., 40Ω ±10%).
Coil Inductance
Several Henries (H), contributing to the valve’s electrical time constant.
Rated Current
Maximum continuous current, typically 10 mA to 150 mA.
Insulation Class
Class H (180°C) or better for high-temperature operation.
Connector Type
Circular (e.g., EN2997 / MS connector) or rectangular multipin (e.g., D-sub). Specific pin configuration.
Wiring
Shielded or unshielded leads of specified length and gauge.
Impregnation
Vacuum impregnated with epoxy or varnish for environmental sealing.
Operational Environment
Designed for the vibration, temperature, and fluid compatibility of the host valve.
G123-825-001
Main Functional Description
The Moog IN123-825-001 is the electromagnetic heart of the servo valve:
Electromagnetic Force Generation: When control current from the servo amplifier flows through the coil(s), it generates a magnetic field. This field interacts with the permanent magnets in the valve’s torque motor, producing a precise torque on the armature assembly.
Mechanical Motion Initiation: This torque causes a tiny, proportional deflection of the armature, which is mechanically linked to the valve’s flapper (in a flapper-nozzle valve) or directly influences the spool (in a direct-drive valve). This minute motion is the first stage of hydraulic amplification.
Signal Fidelity: The coil’s precise electrical characteristics (resistance and inductance) are part of a tuned circuit with the servo amplifier. Any deviation from specification can affect the valve’s frequency response, cause null shifts, or introduce instability in the control loop.
The assembly is not user-serviceable; it is a sealed, calibrated unit. Replacing it requires disassembling the servo valve, which is a specialized task requiring cleanroom conditions and calibration equipment to ensure the valve meets its original performance specifications after reassembly.Application AreasThis coil assembly is a spare part for Moog servo valves used in:
1 Year Warranty
