Product Description:

Bosch Rexroth Indramat manufactured the VT-VSPA-1-21/V0/T5 proportional amplifier card for hydraulic valve control within the VT-VSPA Proportional Amplifiers series. Installed in a 19-inch control rack, the board conditions low-level command signals and drives the solenoid stages of hydraulic valves used for closed-loop positioning and force regulation in industrial automation. By converting voltage references into controlled spool currents, the card allows a PLC to dynamically modulate flow or pressure in presses, molding machines, or material-handling lines.

The electronics operate from a nominal supply of 24 VDC and remain functional down to 18 V, while an upper cutoff at 35 V protects the circuitry from overvoltage. A ready threshold above 16 V lets the drive electronics report power status to the host controller. The command input presents more than 100 kΩ of impedance, so voltage sources are not heavily loaded. A dedicated current input has an impedance of 100 Ω for compatibility with 4–20 mA transmitters. Differential inputs remain above 50 kΩ to minimize common-mode error. A board-mounted fuse rated at 2 A isolates the module during faults, and the regulated 25 mA internal supply feeds the reference generators and feedback stages.

The card follows the Eurocard format with dimensions of 100 × 160 mm and connects to a 48-pin DIN 41612 Form F backplane connector. Onboard references provide a bipolar range of ±10 V ±2% for internal commands and regulated outputs. This stable source works with actual solenoid current feedback of ±2.5 V to simplify valve characterization. Drive current to the power stage is limited to 2.5 A, preventing coil overheating under sustained actuation. The assembly weighs only 0.17 kg, reducing rack loading and allowing dense packaging in multi-axis hydraulic systems.