Product Description:

The VT 3000 S 20-R1 is an analog amplifier card from Bosch Rexroth Indramat in the VT 3000 Analog Amplifiers series. It sits between a motion controller and a proportional hydraulic valve, turning low-level commands into regulated coil current that drives the spool. The card fits a standard Eurocard slot and shares the series back-plane bus for installation in compatible racks. By handling ramp generation, bias control, and fault isolation on board, it reduces real-time load on the PLC. It is intended for hydraulic control systems that need smooth valve response and stable current regulation at the valve interface.

The unit operates from a supply of 24 V DC, which keeps the internal reference stages and drive transistors within their normal range. Total consumption is limited to 30 W, helping the cabinet power budget remain predictable. The power stage can deliver up to 800 mA of coil current, allowing direct actuation of medium-size proportional valves. Command information is accepted as a differential signal of 10 V, which improves noise immunity on long cable runs. The output is optimized for a load resistance near 19.5 Ω, helping the valve current rise in a controlled way without unstable response.

The adjustable ramp generator can stretch a full-scale command change to 1 s, which helps reduce hydraulic shock in large cylinders and other fluid-power loads. Downstream wiring is protected by an on-board fuse rated at 2.5 A. Thermal stability is characterized by a drift of only 0.5‰/K, keeping null offset predictable as ambient temperature changes. At a mass of 0.15 kg, the card places little load on light back-plane frames. Six relays support enable, fault, and limit functions, while a minimum bias current of 20 mA and a minimum input load of 500 Ω support stable idle operation. Physical allocation follows Eurocard norms with seven component-side divisions, one conductor-side division, an eight-division faceplate, and a 5.08 mm division width.