VT-MRPA2-1-1X/V0/0

The VT-MRPA2-1-1X/V0/0 is a proportional amplifier card manufactured by Bosch Rexroth Indramat for the VT-SWMA Modules series. Installed in a hydraulic control rack, it translates an external command voltage into controlled coil current so that a 4/3-way directional valve with two solenoids can meter flow precisely in automated machinery. The module is rated to the IP20 protection class for use inside a closed cabinet where ingress from dust or tools is limited.

The input stage accepts a differential command of ±10 V; any signal inside this range is converted without clipping because the amplifier presents a minimum input resistance of 50 kΩ, minimizing load on upstream controllers. Internal regulation is referenced to the system bus at 24 VDC, yet circuitry remains functional down to the 18 V minimum supply so machines can ride through momentary voltage dips. Drive output is released when the enable line falls below 6.5 V and re-engages above 8.5 V, creating a defined hysteresis band that avoids chatter. For plants that distribute higher panel voltages, the design tolerates a ceiling of 35 V without component damage. These thresholds, together with the oscillator-controlled PWM generator, keep coil energy steady and reduce valve heating during long duty cycles.

Total current draw is limited to 2 A, while apparent power does not exceed 24 VA; these constraints help size cabinet power supplies and thermal management. The internal chopper operates at an oscillator frequency of 5.6 kHz, placing switching noise above the bandwidth of most hydraulic feedback sensors. Field wiring is landed on 12 screw terminals, simplifying maintenance with plain flat-blade drivers. Two output channels energize the paired solenoids that shift the 4/3-way spool, and all conductors are shielded inside the rack enclosure to preserve EMC compliance.