VT-VRPA1-527-10/V0/RTP

The VT-VRPA1-527-10/V0/RTP is an electric amplifier card produced by Bosch Rexroth Indramat within the VT-VRPA Electric Amplifiers series. It conditions command voltages from a PLC or analog controller and delivers controlled current to proportional solenoid valves. The card forms the interface between low-level control electronics and hydraulic actuators in automated machinery.

The card is powered from a single 24 V DC supply, so cabinet designs only need a standard low-voltage bus. Command information enters through a differential ±10 V setpoint that is accepted by a high-impedance input of 100 kΩ; this prevents loading of upstream signal sources. Internal references for sensors are provided by a symmetric ±15 V transducer supply, eliminating the need for external wiring to excite LVDT or pressure transducers. Normal operating current drawn from the cabinet bus is limited to 1.5 A, allowing the module to share power with other control cards without exceeding typical 10 A rail limits. Zero adjustment is possible within ±5% through an onboard trimmer, and a 10 kΩ potentiometer permits gain tuning when valve dynamics require slope correction.

The output stage can deliver up to 2.7 A to a proportional coil while staying below the thermal ceiling of 40 VA; this range covers most NG06 and NG10 hydraulic valves. A dedicated monitor circuit sinks a fault current of 100 mA to signal open-circuit or over-temperature conditions to the PLC. Field wiring terminates on a DIN 41612-F32 plug connector that matches common Eurocard backplanes. The printed circuit board measures 160 mm in length and 100 mm in width, fitting a standard 3U rack. Feedback paths are protected by a main load of 10 kΩ and a pilot feedback resistance of 20 kΩ, ensuring sensor loops remain stable across the amplifier’s full temperature range.