Product Description:

The EEA-PAM-523-A-30 power amplifier card is produced by Vickers within the EEA-PAM Power Amplifiers series. The module conditions command, feedback, and supply signals so that a proportional solenoid valve receives a controlled current in hydraulic automation loops. By translating low-level control voltages into regulated load current, it links PLC analog outputs with the dynamic requirements of industrial actuators.

Its electrical input is centered on a nominal bus of 24 VDC; operation is permitted down to 20 VDC and up to 40 VDC. Line quality is maintained when peak-to-peak ripple does not exceed ±10% pk-pk, and the board disconnects the solenoid if the rail sags to 18 VDC. Under rated conditions the card draws a maximum of 40 W, a figure that guides enclosure heat calculations. These ranges let the amplifier ride through typical machine supply variation while protecting the output stages and attached valve.

Control circuitry is powered from a separate ±15 VDC rail that requires only 50 mA; the low current reduces noise coupling. A maximum ripple of 50 mV pk-pk on this rail keeps the internal reference stable. The reference generator supplies ±10 VDC at 5 mA to external command sources, holding ripple below 20 mV pk-pk and temperature drift under 1 mV/°C. Command enable logic presents 22 kΩ to the driving contact, and the monitor output uses a 10 kΩ impedance so that diagnostic meters do not load the circuit. Valve current can be observed directly because the on-board transducer scales feedback at 1 V/A. During tuning technicians can relate that reading to the originally supplied control rail current and the 5 mA reference limit to confirm the card stays within design margins.