Product Description:

The EEA-PAM-581-C-33 is a plug-in power amplifier card from Vickers, supplied as part of the EEA-PAM Power Amplifiers series. Designed for proportional valve control, the board interfaces between a motion controller and a hydraulic solenoid, shaping command signals into the regulated coil current required for accurate spool positioning. Within an automated press, molding machine, or test stand, it maintains repeatable pressure and flow profiles so that mechanical movement follows the electrical reference provided by the host controller.

A current command arrives through a differential port that presents 100 Ω of input resistance, allowing direct connection to 4–20 mA sources without overloading them. Voltage commands see 22 kΩ of enable-input resistance and cross an enable threshold of 9.8 VDC before the amplifier activates. With the command at zero, the coil still receives 1.7 A, preventing valve deadband. The on-board monitor outputs ±10 V over the full spool stroke for diagnostic scopes, and the driver can supply up to 3.2 A of solenoid current for peak displacement. Separate ramp-enable lines duplicate the 22 kΩ impedance and 9.8 V threshold so that acceleration and deceleration can be switched independently. The voltage input path exhibits 47 kΩ impedance to minimize controller loading, and a ±15 V reference is available at 50 mA for external electronics.

Power is delivered from a nominal 24 VDC supply, and reverse-polarity protection prevents damage if the source is wired backward. The module dissipates up to 50 W, so cabinet ventilation must accommodate the thermal load. If the supply falls to 18 VDC the undervoltage shutdown circuit disables the output, avoiding partial actuation that could destabilize the hydraulic axis. These protection features, combined with the previously noted current and command limits, keep the amplifier stable during start-up, load transients, and ramp-inhibit switching.