Product Description:

The VT-VSPA2-50-1X-T1-002 is a proportional amplifier module produced by Bosch Rexroth Indramat within the VT-VSPA Proportional Amplifiers series. In hydraulic motion systems, it converts low-level command voltages from a PLC or joystick into regulated current for a proportional solenoid, allowing precise valve positioning and repeatable flow control. The card format lets it mount in a standard Euro-rack and tie directly into existing 24 VDC control buses used throughout automated machinery.

This amplifier is powered from a nominal supply of 24 VDC, and at that voltage it draws a biasing current of 50 mA to energize its internal reference networks. A switching stage modulates the solenoid drive at 220 Hz; this clock frequency is high enough to minimize hydraulic chatter while keeping switching losses low. Differential command inputs present a resistance of 100 kΩ, so the upstream controller sees only a small loading error even when multiple cards are wired in parallel. Single-ended command channels accept ±9 V on terminals 1 through 4, while channel 5 is limited to ±6 V, enabling separate gain settings for velocity and pressure loops. The current input load is 100 Ω, matching most process transducers without extra shunt resistors, and a 2.5 AT fuse protects the supply rail from shorted coils.

The output stage can furnish up to 1.5 A of solenoid current, yet the total consumption never exceeds 30 VA, keeping cabinet thermal rise modest. An enable line becomes active at voltages above 8.5 V, providing a hardware interlock for emergency stops. For field power tolerance, the card continues operating down to 22 V and withstands excursions up to 35 V without functional loss. Relay supervision is handled by a 2150 Ω coil that responds at 16.8 V, while overall draw peaks at 1.2 A during cold start.