Product Description:

The VT-SSPA1-1-10/V001 is a plug-in proportional amplifier card produced by Bosch Rexroth Indramat for the VT-SSPA Plugin Proportional Amplifiers series. When inserted into the machine control rack, it converts a low-level voltage reference from the PLC into a controlled current for hydraulic valve solenoids, delivering precise pressure or flow control in industrial automation loops. By placing the power stage close to the valve, it reduces wiring losses and simplifies troubleshooting within distributed manifolds.

The amplifier is designed for a system bus centered on 24 VDC, yet it remains operational down to 18 V and up to 35 V, allowing tolerance for battery-backed or poorly regulated supplies. Current regulation is factory-trimmed; the nominal setpoint is 1.6 A, while a standby bias of 100 mA preserves spool symmetry when no command is present. An input resistance of 20 kΩ ensures that the command source is not heavily loaded, and a 2 A slow-blow backup fuse guards the power line against faults. With a maximum power demand below 40 VA, the card introduces minimal heat into compact enclosures, and its mass of 0.125 kg allows installation without additional support hardware.

At full output, the current loop is pulse-width modulated with a carrier frequency of 340 Hz, which helps avoid audible noise while maintaining tight current resolution. The driver is compatible with valve coils that have 5.5 Ω of resistance and at least 15 mH of inductance; cables can add up to 100 µH before control performance degrades. Peak supply current remains below 1.7 A, so multiple cards can share one low-capacity power module. The board achieves IP65 protection when it is connected to a housing with the same ingress protection rating. A DIN-style solenoid base that complies with EN 175301-803 provides a standardized field connection.