Product Description:

Bosch Rexroth Indramat's VT-SR2-1X/1-60 is a plug-in signal processing board delivered within the VT-SWMA Modules series. It follows the Euro-Card layout, so its 100 mm × 160 mm profile fits standard back-plane frames, and all electrical terminations are routed through a DIN 41612 Design D connector. The unit contains purely analog circuitry that converts control voltages from higher-level controllers into drive signals for hydraulic proportional valves, letting automation systems add closed-loop pressure or flow regulation without separate power supplies.

The module operates from a dual supply centered on ±24 V, and its internal stages draw only 0.15 A, allowing dense rack mounting without exceeding cabinet power budgets. The command input is terminated by 50 kΩ of resistance, which minimizes loading on external reference sources while preserving noise immunity over long cable runs. An onboard oscillator clocks the pulse-width generator at 5 kHz, setting the carrier frequency that modulates the solenoid current so audible hum is avoided and magnetic response remains linear. Because these functions are implemented with discrete operational amplifiers and comparators, the board presents predictable phase characteristics that ease loop-gain adjustment during setup.

Downstream of the modulation stage, a driver circuit limits valve excitation to 60 mA and routes it through a relay whose coil shows 700 Ω of resistance. That relay pulls in once the control voltage reaches 24 V, and its armature completes the solenoid path in about 4 ms, enabling rapid yet repeatable switching. A regulated rail of ±15 V derived from the incoming supply stabilizes the analog references, while the design remains functional between the lower margin of ±22 V and the upper margin of ±28 V to accommodate common industrial power tolerances.