Eaton Vickers EEA-PAM-568-A-32 Proportional Amplifier

The EEA-PAM-568-A-32 is an electronic control module from Eaton's Vickers line, specifically designed to drive proportional pressure and flow control valves. It converts low-power analog command signals into a regulated current output for the valve solenoids, enabling precise hydraulic system response.

Input and Command Signals

The amplifier accepts multiple command signal types: 0-10V DC, ±10V DC, 0-20mA, or 4-20mA, selectable via DIP switches and potentiometers. This flexibility allows direct interface with PLCs, motion controllers, or manual potentiometers. The input impedance is high (20 kOhm for voltage, 250 Ohm for current), ensuring minimal signal loading.

Output Characteristics

The module provides a pulse-width modulated (PWM) current output to the proportional solenoid, with a maximum output current of 2.5A (adjustable). The PWM frequency (typically 100-200 Hz) can be tuned to reduce hysteresis and improve valve response. An integrated dither adjustment (adjustable amplitude and frequency) further minimizes friction and ensures smooth spool movement. The output stage includes short-circuit and overload protection.

Adjustable Functions

Key parameters are easily adjustable via trim pots and DIP switches on the front panel:

• Ramp Time: Independently adjustable ramp up and ramp down from 0.05 to 5 seconds, controlling acceleration and deceleration of the actuator.

• Enable Input: A 24V DC enable signal activates the output; when disabled, the output is cut off.

• Bias/Null Adjustment: Compensates for mechanical offsets in the valve.

• Gain Adjustment: Scales the command signal to the full output range.

Power Supply and Mounting

The EEA-PAM-568-A-32 operates from a nominal 24V DC supply (21-30V DC range) with reverse polarity protection. Current consumption is typically 100mA plus the solenoid current. The module is housed in a compact, IP20-rated plastic case and snaps onto standard 35mm DIN rail (EN 60715). Terminal blocks are pluggable for easy wiring and replacement.

Compatible Valves

This amplifier is primarily intended for use with Vickers proportional valves such as the KB series (directional control), KDG series (throttle), and other single-solenoid proportional valves with similar electrical characteristics. It can also be used with other manufacturers' valves provided the coil resistance and current requirements match.

Environmental and Certifications

The unit is designed for industrial environments with an operating temperature range of 0°C to +50°C. It meets CE requirements (EMC directive) and has high immunity to electrical noise. The enclosure provides basic protection against accidental contact and is suitable for mounting in control cabinets.