WOODWARD 9905-658 TM-25LP Linear Actuator

The Woodward 9905-658, also cataloged as the TM-25LP Linear Actuator, operates as a dedicated hardware component for high-force fuel valve regulation and stroke position execution within engine and turbine control topologies. Configured for panel-mounted deployment in integration with Woodward MicroNet and Atlas control systems, this dual-coil electric module provides direct physical execution by generating mechanical linear thrust to actuate mechanical linkages without hydraulic or pneumatic auxiliary loops.

Hardware Specifications

Actuator Loop Feedback Response and Inductive Coil Control

The 9905-658 relies on external driver cards to regulate its actuator loop feedback response parameters, operating as an open-loop execution block that depends entirely on the command current applied to its dual-coil architecture. Because the module does not include an onboard LVDT or position sensor, terminal stroke precision is managed upstream by the MicroNet or Atlas controller computing real-time process parameters (such as turbine speed or exhaust temperature). The dual independent coils permit redundant signal configurations, stabilizing magnetic flux density inside the actuator housing and isolating individual driver channels from transient cross-talk or inductive back-EMF feedback.

Frequently Asked Questions

Q: How is the linear stroke position verified if the TM-25LP does not contain an internal LVDT or encoder?

A: The 9905-658 is an open-loop mechanical execution module. Position verification must be managed externally through external physical linkages connected to a separate fuel valve position sensor, or via secondary process parameters managed by the primary controller loop.

Q: What structural failure occurs if the dual coils inside the 9905-658 experience an asymmetric current drop?

A: An unbalanced current profile across the dual coils alters the net magnetic force vectors acting on the internal armature. This variance changes the speed and torque limits of the inward retract stroke, which requires the driver card to execute a loop compensation or fault trip.