Product Description:

The VT-VRPA1-537-11/V0/PV is an electric amplifier card produced by Bosch Rexroth Indramat for the VT-VRPA Electric Amplifiers series. As a plug-in module, it conditions control signals and delivers regulated current to proportional solenoid valves and associated position transducers in industrial automation systems. By matching the electrical characteristics of the valve coil and the feedback sensor, the card enables stable closed-loop positioning of hydraulic actuators while fitting directly into a standardized rack.

It operates from a nominal supply of 24 V DC, drawing up to 60 W when all stages are active; under these conditions, the input line can reach 2.5 A. An oscillator working at 7.8 kHz produces a carrier that is pulse-width modulated to drive the valve coils, and the amplitude of this carrier is fixed at 10.8 V RMS to keep force production linear. Command signals are set with a 1 kΩ potentiometer, while deviation monitoring is available through an error output that can source 100 mA for external alarms. Field wiring is terminated on a DIN 41612-F32 connector, and position transducers up to 50 m away can be powered and read without recalibration. The front plate occupies 7 TE, permitting compact installation in Eurocard racks.

The analog power stage supplies up to 3.7 A of controlled coil current, supporting solenoid loads as high as 50 W without saturation. It maintains an identical response with solenoid cable lengths of up to 50 m. The circuit board measures 160 mm in length and 100 mm in width, so it aligns with standard 3U card guides while leaving space for airflow between modules. Its total mass is 0.36 kg, which eases handling and reduces stress on backplane connectors during vibration. The thermal design keeps semiconductor temperatures within limits at the stated ratings. The board’s oscillator voltage, feedback loops, and protective shutdown circuitry operate independently of line variations to preserve valve accuracy during continuous duty.