Product Description:

The VT 2000 K 40 is a plug-in proportional amplifier card produced by Bosch Rexroth Indramat for the VT 2000 Proportional Amplifiers series. It drives hydraulic valve solenoids from a Eurocard rack, converting low-level command voltages into regulated coil current so that flow or pressure changes follow an electrical reference in automation systems. The module fits into a standard 3U slot and integrates supply conditioning, feedback monitoring, and adjustable ramping to match servo-hydraulic demands on presses, molding machines, and test rigs.

All primary connections enter through a 32-pin male DIN 41612 D header, and the board dimensions are 100 x 160 mm, so it occupies a single Eurocard. The amplifier runs from a stabilized field supply of 24 VDC, protected on the board by a 2.5 A T fuse. Two differential command inputs accept up to +9 V and +10 V respectively, while the internal reference produces a fixed +6 V full-scale output for external feedback potentiometers. The power stage can deliver up to 800 mA (+10%/-5%) of solenoid current, and closed-loop regulation is maintained by pulse-width modulation. This output range sets the current envelope and thermal load for direct-acting or pilot valves.

The coil bias circuitry can source up to 300 mA for initial valve offset, and a front-edge test point shows real-time coil current with a 1 mV/mA scale, allowing quick calibration with a handheld meter. For position controllers that use dither coils or LVDT excitation, the auxiliary output supplies a regulated load of ±25 mA from the onboard reference of ±9 V (±1%). The second command channel presents 100 kΩ input resistance, minimizing loading on PLC analog cards. Solenoid windings down to 19.5 Ω are supported, while the supply watchdog disconnects the stage if bus voltage drops below 22 V or rises above 35 V to protect power transistors.