Product Description:

The EEA-PAM-591-A-10 power amplifier card is produced by Vickers and belongs to the EEA-PAM Power Amplifiers series. Within industrial hydraulic automation it converts low-level command signals into controlled solenoid current so that proportional valves can meter pressure or flow in response to a machine controller. The board fits a standard plug-in rack slot and interfaces with controller I/O through multi-pin edge connectors.

The amplifier operates from a regulated supply of +24 VDC; at a 200 mA coil load its internal draw stays below <500 mA, allowing multiple cards on a single power bus. On-board converters furnish a dual control rail of ±15 VDC that can source up to 50 mA for external transducers. Voltage commands are accepted through a buffered port that tolerates a span of ±10 VDC and presents a high input impedance of 100 kΩ, reducing signal source loading. When voltage mode is not preferred, a 4–20 mA loop can instead drive the current-mode input; internally the card conditions these references and scales the output stage so that factory trim delivers up to ±200 mA to the valve coil.

The current interface allows peak reference levels of 20 mA through a precision 249 Ω network, matching common transmitter standards. A factory-set dither of 200 Hz is superimposed on the coil current to minimize static friction in the valve spool. Continuous operation is specified to ambient temperatures reaching 50 °C, while safe storage from −25 °C to 85 °C protects spare units in the parts crib. Additional service points include an output monitor at 1 mV per mA, a pre-amp tap of ±6 V/2 mA for waveform checks, and a PID feedback node of ±10 V/5 mA that simplifies loop tuning during commissioning.