EEA-PAM-581-C-30 by Vickers

The EEA-PAM-581-C-30 is a plug-in power amplifier card produced by Vickers for the EEA-PAM Power Amplifiers series. In hydraulic automation, this module accepts low-level commands from a motion controller and conditions them so a proportional valve receives a clean, ramped drive signal. By combining reference sources, ramp generators, and supply monitoring on one board, it supports presses, molding machines, and other equipment that require stable fluid-power regulation without external signal conditioners. Its plug-in format also allows the amplifier to fit into compatible control hardware without a separate external amplifier module.

The card draws its main energy from a nominal supply of 24 V DC, and overall consumption does not exceed 40 W, which helps limit heat inside the cabinet. Signal electronics are powered by a dedicated rail of ±15 V, and the logic on that rail requires only 50 mA, which keeps demand on the control supply low. Separating the signal rail from the main input helps the control section remain stable while the valve stage is operating. The amplifier tolerates up to 10% peak-to-peak ripple on the 24 V feed, while the reference circuitry keeps its own noise below 20 mV peak-to-peak for accurate valve positioning. Four onboard potentiometers set independent up, down, and dither parameters, so ramp characteristics can be tuned without removing the card.

Dynamic behavior is controlled through adjustable ramp times. The slowest slope reaches 5 s to reduce hydraulic shock in large cylinders, and the fastest transition shortens to 0.050 s when quicker response is required. For external command generation, the board offers a constant current reference of 5 mA or a voltage reference of ±10 V, giving downstream controllers two standard interface options. This range allows the same card to support gentle starts or faster changes in motion, depending on the machine cycle. Protection is provided by an under-voltage circuit that disables outputs when the supply falls to 18 V DC, which helps prevent erratic valve movement until normal power returns.