Product Description:

Bosch Rexroth Indramat manufactures the VT 2000 S 44 proportional amplifier card as a member of the VT 2000 Proportional Amplifiers series. Installed in hydraulic control racks, the module interfaces between a machine controller and a proportional valve. It converts low-power control voltages into modulated coil current so a valve spool moves in proportion to the reference, enabling repeatable pressure and position regulation within automated presses, molding machines, or test stands. Its compact construction and plug-in connectors simplify installation in densely populated manifolds.

The amplifier is built on a Euro card that occupies a faceplate width of 8 divisions inside a standard 19-inch subrack. The supply rail must furnish 24 VDC, protected by the integrated 1.2 A time-delay fuse so transient inrush currents do not trip cabinet breakers. Command references reach the electronics through a single-ended input that saturates at +9 V, while a differential pair can swing to +10 V for noise-immune transmission over longer cable runs. Internal circuitry scales actual output current to 1 mV/mA, allowing valve drive current to be measured with a handheld meter at the front test points. Under dynamic demand, the power stage can source up to 800 mA, which is sufficient for most NG06 and NG10 proportional solenoids. With a mass of only 0.15 kg, the card adds very little load to cabinet slide rails.

At the monitor jack, a full-scale reading of +6 V mirrors the command path so signal integrity can be checked without removing the card. A preset bias injects at least 100 mA into the coil to overcome valve hysteresis before proportional control begins, and loop stability is maintained only when the driving device presents a minimum load of 500 Ω at the input terminals. Pulse-width modulation operates at 200 Hz, shifting hydraulic noise above typical machine resonance bands while preserving fast response. Continuous service is specified for ambient temperatures up to 50 °C; above that point, the output stage may derate to protect components, so ambient conditions should remain within the stated operating range.