The R901439038 (VT-MSPA2-21-F5-000-000) is a compact, modular analog valve amplifier developed by Bosch Rexroth Indramat. Utilized primarily in industrial hydraulics, this amplifier is designed to control proportional valves without electric position feedback. Designed specifically for proportional valves with two solenoids, this device features independently adjustable ramp generators. It can be easily installed on top hat rails and connected electrically through three tension spring plug-in connectors. Notable features include a zero-point setting, clocked power output stage, short circuit-proof output stages, and a fault recognition functionality that detects cable breaks and over-currents in the output stage. In terms of specifications, the R901439038 (VT-MSPA2-21-F5-000-000) operates at a nominal supply voltage of 24 VDC, with a tolerance range between +40% and -20%. It tips the scale at a modest 0.14kg and powers up in less than a second. The amplifier is manufactured to comply with the EN 60529 standard, which confirms its protection category as IP 20, restricting the entry of solid foreign matter but excluding hydraulic fluids. Made from glass-fiber reinforced polyamide plastic, the device is UV-resistant and can operate effectively in temperatures up to 60°C. The recommended maximum installation altitude is 2000m.
