Rexroth VT5035-17 Proportional Amplifier Card – VT5035 Series

Rexroth VT5035-17 Proportional Valve Amplifier Card — Precision Current Driver for Closed-Loop Hydraulic Control

The Bosch Rexroth VT5035-17 is a dedicated proportional solenoid amplifier card engineered to condition and deliver regulated drive current to Rexroth proportional directional control valves, proportional pressure valves, and proportional flow control valves. Within a hydraulic control loop, this card occupies the critical interface layer between the PLC or process controller analog output and the valve solenoid coil — translating a ±10 V DC or 4–20 mA command signal into a precisely regulated milliampere output that determines spool position, and therefore actuator velocity, force, or pressure, with sub-millisecond response fidelity.

Unlike simple on/off relay-driven valve circuits, proportional control demands that the amplifier card maintain output current linearity across the full command range, compensate for solenoid coil resistance drift caused by temperature variation, and suppress electrical noise that would otherwise manifest as valve hunting or positional instability. The VT5035-17 addresses each of these requirements through its onboard current-regulated output stage, adjustable dither injection, and configurable ramp generation — all accessible via front-panel potentiometers without external programming hardware.

This card is a direct form-fit-function replacement within the VT5035 amplifier family and is compatible with Rexroth 4WRPH, 4WRKE, DBET, DBEM, and DREM series proportional valves. Its Euro card mechanical format allows installation into standard Rexroth VT-RACK card cage assemblies or equivalent DIN rail enclosures, preserving existing cabinet wiring and connector assignments during retrofit operations.

Real-time Stock & RFQ: [email protected] | WhatsApp: +86 18359268345

Technical Parameters

Hardware Logical Analysis

The VT5035-17 is structured around three functional hardware blocks that operate in sequence to deliver stable proportional solenoid drive.

Input Conditioning Stage: The analog command signal — whether ±10 V DC from a PLC analog output module or a 4–20 mA transmitter loop — enters a differential input amplifier with high common-mode rejection ratio (CMRR). This topology rejects ground-loop noise and cable-induced common-mode interference, which is particularly significant in hydraulic machine environments where long cable runs between the control cabinet and valve manifold are common. The input stage also performs signal scaling and zero-offset correction via the onboard potentiometer, allowing the card to be calibrated to match the actual valve null position without modifying PLC output parameters.

Ramp and Dither Generation: The conditioned command signal passes through a ramp generator circuit that independently limits the rate of change on the rising and falling edges of the command. This is not a software ramp — it is implemented in analog hardware, meaning it operates with deterministic latency independent of any scan cycle or task scheduling overhead. The ramp function prevents hydraulic shock (water hammer) in long pipe runs and protects actuator seals from pressure spikes during direction reversals. Superimposed on the ramp output is a dither signal: a low-amplitude, high-frequency AC component injected into the solenoid drive current. Dither keeps the valve spool in continuous micro-motion, eliminating static friction (stiction) in the spool bore and ensuring that the valve responds to small command increments without a deadband threshold. The dither frequency and amplitude are independently adjustable to match the mechanical resonance characteristics of the specific valve model installed.

Current-Regulated Output Stage: The output driver is a closed-loop current regulator, not a simple voltage amplifier. It continuously measures the actual solenoid coil current via a sense resistor and compares it against the demanded setpoint. Any deviation — caused by coil heating (resistance increase), supply voltage fluctuation, or cable resistance variation — is corrected within the feedback loop. This current regulation is the fundamental mechanism that ensures valve spool position remains proportional to the command signal regardless of thermal or electrical disturbances. The output stage also incorporates protection against short-circuit and open-load conditions, with fault indication available via the card’s status LED.

EMC Design: The card layout follows Rexroth’s industrial EMC design rules: power and signal traces are physically separated, decoupling capacitors are placed at the supply pins, and the output driver switching edges are slew-rate controlled to limit radiated emissions. The card is designed to meet IEC 61000-4-2 (ESD), IEC 61000-4-4 (EFT/burst), and IEC 61000-4-6 (conducted RF immunity) without external filtering, which simplifies cabinet design and reduces component count.

System Integration Benefits

• Deterministic analog response: Hardware ramp and dither circuits operate independently of PLC scan cycles, delivering sub-millisecond command-to-output latency that software ramp functions cannot match in time-critical press or injection molding sequences.
• Thermal drift compensation: Closed-loop current regulation corrects for solenoid coil resistance increase of approximately 0.4% per °C, maintaining valve positioning accuracy across the full operating temperature range without recalibration.
• Stiction elimination: Adjustable dither injection reduces effective valve deadband from a typical mechanical stiction threshold of 1–3% of rated current to below 0.5%, improving low-speed actuator controllability in precision positioning applications.
• Hydraulic shock suppression: Independent ramp-up and ramp-down adjustment allows the control engineer to tune deceleration profiles separately from acceleration profiles, critical in asymmetric actuator loads such as vertical press rams where gravity affects the return stroke dynamics.
• Drop-in retrofit compatibility: Euro card format and DIN 41612 connector pinout are preserved across the VT5035 series, allowing replacement of earlier revision cards without rewiring the cabinet or modifying the valve manifold connector block.
• Broad valve family support: A single card variant covers multiple Rexroth proportional valve families (4WRPH, 4WRKE, DBET, DBEM, DREM), reducing the number of spare card types that a maintenance department must stock for a multi-valve machine.
• No external programming tool required: All calibration parameters (gain, zero, ramp, dither) are accessible via front-panel potentiometers, enabling field commissioning and adjustment without a laptop, software license, or fieldbus connection — a practical advantage during machine startup or emergency maintenance.
• Fault transparency: Onboard LED status indication provides immediate visual feedback on enable state, output active state, and fault conditions (short-circuit, open load), reducing diagnostic time during commissioning and troubleshooting without requiring oscilloscope access to the output terminals.
• CE and RoHS compliance: Meets EU Machinery Directive and EMC Directive requirements, enabling direct integration into CE-marked machine assemblies for European market export without additional component-level certification effort.
• Proven field reliability: The VT5035 amplifier card series has accumulated a multi-decade installation base across automotive stamping, steel rolling, plastics processing, and marine hydraulic applications, with documented mean time between failure (MTBF) data available in Rexroth’s reliability documentation.

Quality Assurance & Global Logistics

Every Rexroth VT5035-17 unit supplied by siemensplc.com is sourced through verified channels and subject to a structured pre-shipment inspection protocol before dispatch from our Xiamen, China operations center.

Authenticity Verification: Each card is inspected against Bosch Rexroth’s published label specifications, including part number format, date code structure, and holographic security markings where applicable. Counterfeit screening is applied to every batch received, with suspect units quarantined and returned to the supply chain without exception.

Functional Inspection: Where test fixtures are available, cards undergo bench-level functional verification: supply voltage application, enable signal activation, command signal sweep, and output current measurement against the published specification range. Visual inspection covers PCB condition, connector pin integrity, and potentiometer mechanical condition.

Packaging: Units are dispatched in anti-static ESD shielding bags, placed within foam-lined rigid cartons with moisture-barrier desiccant packs. This packaging standard is maintained for all international shipments regardless of destination climate zone.

Documentation Package: Each shipment includes a commercial invoice, packing list, certificate of conformity, and country of origin declaration. The Rexroth RE 30028 data sheet is available electronically upon request. Export classification and HS code documentation are prepared for all international consignments.

Logistics: In-stock units ship from Xiamen within 1–3 business days via DHL Express, FedEx International Priority, or UPS Express — carrier selection based on destination and customer preference. Transit times to Europe: 3–5 business days. North America: 4–6 business days. Southeast Asia: 2–3 business days. Full tracking numbers are provided at time of dispatch. For urgent requirements, same-day dispatch is available on confirmed orders received before 14:00 CST.

Warranty: 12-month warranty against manufacturing defects from date of delivery. Defective units are replaced or credited following return merchandise authorization (RMA) and inspection. No restocking fees apply to warranty claims on verified defective units.

Contact Information

Email: [email protected]
WhatsApp: +86 18359268345
Web: siemensplc.com
Location: Xiamen, China
© 2026 siemensplc.com. All rights reserved.