Product Description:

The VT-VSPA1-1-1X-SO43A-1616 is a plug-in proportional amplifier card manufactured by Bosch Rexroth Indramat within the VT-VSPA Proportional Amplifiers series. Installed in a hydraulic control cabinet, the card interprets electrical reference signals and modulates the coil current of proportional directional or pressure valves. By acting as the interface between a PLC and the valve solenoid, it enables automated machinery such as presses, injection molders, and material-handling lines to achieve continuously adjustable flow or pressure rather than simple on/off actuation.

Primary power is supplied at 24 VDC. Onboard regulators keep the circuitry functional down to 22 VDC and disconnect it above 35 VDC to protect components. During full modulation, the board draws up to 1.8 A, which equates to a peak demand of 50 VA on the control power supply. A 2.5 A time-lag fuse on the input guards against sustained overloads. Command Input 1 handles 0–9 V single-ended references, while a differential stage accepts 0–10 V with an input resistance of at least 100 kΩ to avoid loading upstream cards. A separate 4–20 mA loop receiver is included, and the card provides an internal 0–6 V source plus a ±9 V ±1% potentiometer feed for setting bias and gain.

Connection to the rack is made through the 32-Pole DIN 41612 Design D connector, which mates with standard backplane racks. For systems that transmit current references, the dedicated input supports 4 to 20 mA loops, and the amplifier reports actual solenoid current on a 0–1.6 V monitor terminal. Voltage-based drives can instead use the differential 0 to 10 V path. Specified operation extends from 0 to 50 °C, while passive components tolerate storage between -25 and 85 °C. Power stages shut down gracefully when ambient limits are exceeded, preventing thermal drift and supporting predictable valve behavior across the stated electrical operating range.