VT-VRRA1-527-20/V0/KV-AGC

The VT-VRRA1-527-20/V0/KV-AGC is a plug-in electric amplifier built by Bosch Rexroth Indramat for the VT-VRPA Electric Amplifiers series. The card converts low-level command signals into controlled current for proportional solenoids used in hydraulic valves, giving machine controllers a direct way to modulate flow or pressure without mechanical linkages. It slides into a standardized 19-inch rack and interfaces with system wiring through a rear backplane, supporting consistent integration in industrial automation panels.

The amplifier operates from a stabilized input of 24 VDC. Under normal conditions, it draws only 37 W, so cabinet power supplies remain lightly loaded. Peak consumption is limited by a maximum current draw of 1.7 A, which helps determine fuse and trace sizing on the supply bus. When energizing the connected proportional valve, the output stage can deliver up to 2.7 A of solenoid current, providing adequate magnetic force for high-flow cartridges. Control accuracy at the command interface is aided by a 100 kΩ command input resistance that minimizes loading on upstream controllers and preserves signal fidelity.

The feedback network inside the module compares coil current with an internal reference through an actual-value resistance of 20 kΩ, producing a closed-loop response that corrects deviations quickly. The front plate has a width of 7 TE, allowing multiple cards to fit closely within a single subrack without overlap. All electrical contacts are routed through a robust DIN 41612-F32 plug-in connector for dependable mating. For diagnostic outputs, the unit limits error signaling to 100 mA, protecting sensitive input stages on monitoring equipment. The card weighs 0.40 kg, which places little additional load on the rack structure. A recommended 4 × 0.5 mm² position cable carries the associated signals between the amplifier and connected equipment.