Product Description:

The VT 2000 S 43 proportional amplifier card is produced by Bosch Rexroth Indramat as part of the VT 2000 Proportional Amplifiers series. Intended for rack installation in hydraulic control cabinets, the unit converts voltage commands into controlled solenoid current so that directional or pressure valves follow a repeatable profile. By closing the loop between a machine controller and the valve coil, it supports consistent motion or force output in automated presses, plastics machinery, and general factory equipment.

Normal operation requires a supply of 24 VDC, but the board tolerates input down to 22 V and up to 35 V to accommodate battery-backed or lightly regulated sources. The differential command stage presents 100 kΩ of input resistance, limiting load on upstream electronics while accepting a full-scale reference of +6 V. Internally, this reference is converted to an auxiliary rail that delivers ±9 V to external potentiometers or sensors. During dynamic valve shifts, the amplifier can draw as much as 1 A maximum, yet overall power consumption stays below 25 VA. Overcurrent protection is provided by a 2.5 A time-lag fuse, and the card itself weighs 0.1 kg, easing panel load calculations.

The output stage supplies a nominal coil current of 800 mA to match proportional valve solenoids with a resistance of 19.5 Ω. For initial spool shift, a bias current up to 300 mA can be set, and fine control is achieved through a regulated monitor pin that sources ±25 mA for external feedback circuits. The minimum ramp generator limits the step response to 30 ms, smoothing pressure or speed transitions and reducing hydraulic shock. Actual valve position can be verified with an 800 mV full-scale feedback signal that tracks the command. The wide input range helps the amplifier remain active during supply dips or surges.