Product Description:

The VT-MRPA2-1-1X/V0/0 is an electro-hydraulic pilot card produced by Bosch Rexroth Indramat for the VT-SWMA Modules series. Designed to drive two proportional solenoids in a 4/3-way valve assembly, the card converts electrical command signals into regulated coil currents that position the hydraulic spool. In automated machinery, it forms the interface between a PLC’s low-level reference and the power stage of the valve, enabling pressure or flow control with repeatable accuracy.

Its command value input accepts ±10 V, allowing standard industrial differential signals to modulate the spool position across the full stroke. Field wiring is completed through 12 screw terminals, which provide segregated points for supply, enable, feedback, and both solenoid outputs. The amplifier becomes active when the enable line rises above 8.5 V and is disabled once the voltage drops below 6.5 V, giving a defined hysteresis that prevents chatter during borderline conditions. During normal operation, the card draws up to 2 A from the 24 VDC rail; multiplied by internal losses this produces a maximum apparent power of 24 VA, information that is required when sizing the control cabinet’s auxiliary power transformer.

The electronics tolerate supply excursions from 18 V up to 35 V, yet optimum accuracy is achieved at the rated 24 VDC operating level. To protect upstream analog sources, the command circuit exhibits a minimum input resistance of 50 kΩ, so sourcing devices deliver only microamp currents. A pulse-width modulated driver running at 5.6 kHz excites each solenoid; the high frequency keeps hydraulic dithering inaudible while reducing static friction. The module carries an IP20 enclosure class, so it must be installed inside a closed panel, and its two output stages correspond exactly to the dual-coil requirement of the referenced 4/3-way valve. The two solenoid channels maintain full stroke even when supply falls to 18 V.