Proportional Valve Servo Amplifier

The servo amplifier electronics connect an electrical command to movement of a proportional valve. In the modeled feedback arrangement, the command is compared with the position reported by LVDT feedback, and the drive electronics adjust the solenoid's actuation. The sensor reports position; the power stage supplies the electrical drive needed to change it.

The component list separates those jobs. A microcontroller handles the control logic, the feedback circuit conditions the sensor signal, and the driver stage controls the coil drive. The circuit board and passive components connect and support these functions. This is a functional breakdown, not a complete board schematic.

One practical distinction is a separate amplifier card versus electronics integrated into the valve. Moog's electronic-feedback valve overview describes onboard electronics that remove the need for an external controller card. Its direct-operated valve description also identifies closed-loop spool-position control. Controlling the spool is not the same as directly measuring every pressure, load, or actuator position elsewhere in the hydraulic system.

For a hydraulic test bench, that boundary matters when identifying which feedback signals the test needs. The generic board shown here is not a drop-in replacement specification. Command interface, coil requirements, feedback compatibility, tuning, and fault behavior depend on the exact valve and electronics combination.