Product Description:

The VT 2000K4X-1 proportional amplifier card is produced by Bosch Rexroth Indramat for the VT 2000 Proportional Amplifiers series. It converts low-level command signals into controlled solenoid current that positions hydraulic proportional valves. By shaping a ramped command and regulating coil saturation, it improves valve linearity and helps extend component life. Installed in industrial machinery, the board fits Eurocard racks and links system power, feedback, and control lines for automated pressure or flow control. This arrangement supports smooth valve response during repeated machine cycles without adding unnecessary complexity to the control cabinet.

The card uses the Eurocard format with dimensions of 100 x 160 mm and plugs into a 32-pin DIN 41612 Form D backplane connector. Its internal oscillator runs at 200 Hz, which sets the pulse-width-modulated drive frequency applied to the valve. The nominal operating voltage is 24 VDC with a tolerance of +40/-5 %, and protection is provided by a 2.5 A time-lag fuse with a lower shutdown threshold at 22 V. The output stages can deliver up to 800 mA of solenoid current, while a separate bias channel supplies current for valve offset adjustment. Quiescent current draw remains below 1 A, and temperature-stable components in the PWM modulator help maintain consistent operation under typical cabinet temperatures.

The amplifier’s energy demand stays below 25 VA. A configurable ramp generator can extend command transitions to 5 s, which helps reduce hydraulic pressure shock during changing commands. Closed-loop circuitry limits output deviation to ±25 mA and holds feedback voltage to ±9 V with 1% accuracy. Input 2 has a high impedance of 100 kΩ, so the connected analog source sees very little load during operation. The design also accommodates a solenoid resistance of 19.5 Ω and accepts a maximum permitted supply of 35 V to help protect the circuit from surges.