Product Description:

The VT-VSPA1-1-E10 from Bosch Rexroth Indramat is a plug-in proportional amplifier card delivered as part of the VT-VSPA Proportional Amplifiers series. It converts low-level command voltages into controlled coil currents for directional or pressure proportional valves used in industrial automation. Installed in a Eurocard rack, it conditions reference signals, limits power draw, and supplies the precise current needed for repeatable valve positioning, making it a key interface between PLC analog outputs and hydraulic actuator field devices. This type of card is used where hydraulic motion must respond smoothly to electrical setpoints rather than switch abruptly between fixed positions.

Its main supply operates nominally at 24 VDC, with an acceptable window from 22 VDC to 35 VDC, so the card tolerates typical battery-buffered or rectified power rails found in control cabinets. Under maximum load conditions, the electronics draw 1.8 A, translating to a ceiling of 50 VA; these figures help with cabinet fuse sizing and power supply selection so the module remains stable during rapid valve actuation. A slow-blow 2.5 A fuse mounted on the front edge protects the circuitry against sustained overcurrent events. Internal regulators derive ±9 V auxiliary rails for signal processing, allowing the module to deliver stable dither and ramp functions even when the main bus fluctuates. These internal rails also support the card’s control stages as the command signal changes during operation.

The signal interface follows the DIN 41612 Form D pinout, enabling direct insertion into standardized 32-way backplanes without custom wiring. A command channel with 1 kΩ input resistance minimizes loading on upstream analog modules and accepts a full-scale reference of +6 V, which the card interprets as 100 percent valve stroke. The auxiliary section needs only 25 mA, so the ±9 V rails can be shared across multiple cards without exceeding common backplane limits. This arrangement allows the module to work with common analog control sources in rack-based hydraulic systems.