Product Description:

The VT-VSPA2-50-1X-T1 proportional amplifier is produced by Bosch Rexroth Indramat within the VT-VSPA Proportional Amplifiers series. It conditions command signals and supplies controlled current to directional or pressure proportional valves so a PLC can modulate hydraulic actuators with repeatable accuracy. The card format integrates into 32-pin backplanes that follow DIN 41612 Form D, allowing the module to fit neatly inside an industrial control rack.

The module operates from a regulated supply of 24 VDC (+40%/-5%) and draws less than 1.2 A, while the internal oscillator runs at 220 Hz ±10% to generate chopper pulses for the power stage. Its differential input accepts 0 to ±10 V on channels 1 through 4, plus a separate ±6 V input on channel 5, with a 100 kΩ load to minimize controller burden. When enabled by a logic level above 8.5 V, the amplifier can deliver up to 1.5 A of solenoid current, trimmed by the bias network and the single ramp-time counter. System protection is provided by a 2.5 AT fuse situated on the card edge, while the ±9 V reference supply is held within ±1% for stable signal conditioning.

The bias circuit supplies 50 mA ±25% to preset valve overlap, and the analog section presents a 100 kΩ input impedance that resists ground-loop currents. Overall energy demand is capped at <30 VA, helping cabinets manage heat while the unit remains within a service range of 0 to 50 °C. The ramp counter designated as 1 provides a single adjustable up- and down-slope so flow changes occur smoothly rather than in steps. Fuse replacement is simplified because the card front carries the 2.5 AT component behind a pull-out holder. Output monitoring is assisted by test pins that expose the ±9 V regulated rails and the solenoid current feedback during setup without removing the board from its backplane.