Eaton Vickers EEA-PAM-525-A-33 Proportional Amplifier

The EEA-PAM-525-A-33 is a high-performance proportional amplifier card from Eaton's Vickers line, designed to interface between a control system (PLC, motion controller) and a hydraulic proportional valve. It converts a low-level analog command into a regulated current output suitable for driving the valve solenoids.

Input Signal

The amplifier accepts differential voltage command signals, typically ±10V DC (or 0-10V, selectable via jumpers). Input impedance is 20 kOhm. It also includes a differential enable input (24V) that activates the output stage. The command signal can be inverted via a switch to change valve direction.

Output Characteristics

The output is a pulse-width modulated (PWM) current, adjustable up to 2.5A maximum (depending on valve coil resistance). The PWM frequency is factory-set (e.g., 200 Hz) but can be modified via an external resistor. The module includes adjustable dither (amplitude and frequency) to reduce valve hysteresis and improve spool response. Short-circuit and overload protection is built-in.

Adjustable Parameters

Front panel potentiometers and DIP switches allow tuning of:

• Ramp times: Independent acceleration and deceleration ramps from 0.05 to 5 seconds.

• Gain: Scales the command to output current.

• Bias (null): Offsets output to center spool.

• Max current: Limits output to protect valve.

Power Supply and Isolation

The module requires a 24VDC nominal supply (21-30V range). Current consumption is approximately 100mA plus solenoid current. It is not isolated between signal and power; however, the command signal is differential to reject common-mode noise.

Mounting and Environment

Housed in a compact plastic case (approx. 100 x 75 x 25 mm) with IP20 protection, it snaps onto 35mm DIN rail. Operating temperature: 0°C to +50°C. Screw terminals accept up to 2.5mm² wires. LED indicators for power and enable status.

Compatible Valves

This amplifier is designed for Vickers proportional valves with single or double solenoids, such as KDG4V-3, KDG4V-5, and similar models. It can also be used with other brands if coil current requirements match.

Applications

Typical uses include injection molding machines, presses, test rigs, and industrial automation where precise hydraulic motion is required.