VT-VPRAP1-540-10/V0/T-SI

The VT-VPRAP1-540-10/V0/T-SI is an electric amplifier card produced by Bosch Rexroth Indramat for the VT-VRPA Electric Amplifiers series. Installed in hydraulic drive cabinets, it interfaces with proportional valves used for pressure and position regulation in industrial automation systems. The card translates low-level command voltages into controlled solenoid currents, allowing the connected valve to respond accurately to control signals. Its plug-in design supports installation in compatible amplifier racks without requiring a separate external current regulator.

This European-format card operates from a nominal bus of 24 V DC and draws a logic supply current of 1.7 A. A feedback-oriented PI loop manages spool travel, while the output stage uses a clocked current regulator that modulates coil energy without generating excessive heat. For direct actuation, the card can deliver a peak coil current of 2.7 A, which is adjustable through a 10 kΩ potentiometer on the front edge. Process signals reach the unit through a DIN 41612-F32 connector, and the card is 7 TE wide to fit standard 19-inch subracks. Internal pressure tapping through T1 supplies the pilot fluid path. The flushing function purges contaminants during critical transitions, helping protect valve operation. Position commands are processed through PI control to minimize steady-state error and maintain accurate spool movement.

The total electromagnetic load delivered to the valve is limited to 40 W, keeping the thermal rise within acceptable enclosure limits. Diagnostic monitoring is supported by a fault output rated at 100 mA maximum, which reports coil or supply anomalies to a PLC. A separate enable line accepts an external controller signal rated at 24 V and 0.1 A maximum, providing controlled startup sequencing. Energy storage for sudden current changes is provided by a 4700 μF, 63 V DC smoothing capacitor, which buffers the supply rail during rapid solenoid switching. The internal flushing channel is governed by the pressure supply arrangement and removes residual oil when commanded. This function helps the valve resume dynamic positioning after extended periods of inactivity.