Denison Hydraulics Multi-Function Proportional Valve Dual Driver (Encapsulated)
This document describes the Denison Hydraulics Multi-Function Proportional Valve Dual Driver, an encapsulated unit designed for controlling proportional valves in various industrial and mobile applications. The device, identified by part number 027-22071-0, is engineered to provide reliable and efficient operation in demanding environments.
Function Description
The Dual Driver unit is a sophisticated electronic controller designed to operate continuously from a single polarity +12VDC (±10%) or +24VDC (±20%) supply voltage. The choice of supply input voltage is made by selecting the appropriate output current links for the valve(s) being driven.
At its core, the driver utilizes a 'MosFet' type output stage with 'Current Feedback' to ensure accurate and efficient operation. This design provides an unrivaled linear output characteristic relative to a linear command voltage. A critical aspect of its design is that each valve coil MUST be individually connected using separate cables; none of these wires should be connected to Earth, 0V, or shared with any other valve driver or coil.
The output driver is 'Normally Off' but activates upon application of a command signal, employing Pulse Width Modulation (PWM). The PWM frequency, set via 'F' links, is adjustable to suit the specific valve type and size. This also generates a 'Dither' signal, crucial for preventing 'Stiction' and minimizing mechanical 'Hysterisis' in the valves.
The proportional output drive supports 'Double Solenoid' valves in a 'Push-Push' configuration, where only one of the two solenoids per valve is energized at any given time. Internally, the circuit is configured such that a positive (+) voltage command energizes the 'A' output drive, while a negative (-) voltage command operates the 'B' output driver. Alternatively, it can control a 'Single Solenoid' valve connected to output 'A' and reacting to a positive (+) command signal.
The valve's start point (minimum current) is set by 'I Min', and the end point (maximum current) is set by 'I Max' for each individual coil using front panel potentiometers. The minimum output value (I Min) is only applied after an internal Comparitor Detection Circuit has been exceeded by the incoming command signal. The 'I Min' A & B and 'I Max' A & B adjustments are CLOCKWISE to INCREASE and ANTI-CLOCKWISE to DECREASE the output current. These potentiometers are approximately 20-turn varieties with mechanical end stop slipping clutches to prevent over-adjustment.
The standard unit defaults to a +/-5V command input, but this can be easily changed by altering link positions to accept 0 to +/-20mA or 0 to +/-10V command signals. The internal Comparitor Detection Circuit ignores command signals up to ±170mV (for ±10V command) and ±85mV (for ±5V command). This 'Zero-Band' ensures that zero drive is achieved without erroneous valve operation due to electrical noise and accommodates mechanical tolerances in joysticks or potentiometers.
The unit incorporates a linear Ramp Generator, fully adjustable from 20mS to 10 Secs (approx.) via front panel potentiometers. The 'UP' slope adjustment affects signals transitioning from a numerically smaller to a larger value, while the 'DOWN' adjustment affects signals transitioning from a larger to a smaller value. Both ramp generator adjustments are CLOCKWISE to INCREASE and ANTI-CLOCKWISE to DECREASE the rate of change of signal (longer and shorter ramp time, respectively). These potentiometers are also 20-turn varieties with slipping clutches.
The Dual Driver controller is designed to accept a range of optional 'Add-On' sub-boards that enhance its base characteristics. These sub-boards, which fit onto vertical connector pins and are secured by a single M3 plastic screw, include:
- 027-22072-0: 4-20mA command input board with safety alarm and override. This board features a 'Loop Fault' detector circuit that activates if the current loop input falls below approximately 3.7mA. In such a case, the command signal is immediately sent to zero, and the output LEDs 'A' & 'B' turn off. An open collector transistor circuit is triggered, and a front panel RED LED illuminates, indicating a fault. For bi-directional output, if the current command returns to 4mA after a fault, the valve driver will command full drive in the 'B' coil direction, which can be dangerous. It is strongly recommended that the 'Loop Fault' detect circuit output be integrated into the control system to send the command to 12mA (zero) and activate the 'Emergency Stop' on the base unit for safety.
- 027-22073-0: Voltage Summing options board. This board allows for simple voltage signal summation/subtraction and setting hydraulic 'Offsets' electrically, useful for applications requiring minimum tension at zero command signal. On-board links allow setting signal polarity.
- 027-22074-0: Inductive Joystick options board. This option enables interfacing with inductive joysticks from various manufacturers, with provisions for output gain settings. One sub-board can condition two channels from an 'X', 'Y' joystick to control two dual driver controllers for a full system.
- 027-22075-0: Electronic Horse Power limiter options board. This option provides effective and cost-effective HP limiting with better accuracy and repeatability than standard mechanical versions. It allows for setting and controlling lower HP and offers remote setting and operation using a 900 series pump stroker.
Important Technical Specifications
Electrical Specifications:
- Board Style: Denison Hydraulics Unique Size and Mounting.
- Connector Type: Heavy Duty Two Part Polarised 'Screw' Type Terminal Connectors.
- Input Supply Voltage(s): +10 - +32 VDC (Max) (supply volts same as coil voltage).
- Input Supply Current (Max): Maximum Valve Current Setting + 200mA Quiescent (Max).
- User Output Voltages: +/- 5V D.C. (+/-5%) Rated @ 5mA Per rail.
- Command Input Type(s): D.C. Voltage and Current.
- Command Input Value(s): +/-5V, +/-10V & 0 to +/-20mA.
- Available adjustments: I Min 'A', I Max 'A', I Min 'B', I Max 'B', Ramp UP, Ramp DOWN.
- Ramp Type: Linear and Continuously Variable by 20 Turn (+/- 5 Turns) Potentiometers.
- Min Ramp Time UP: 20mS (±20%).
- Maximum Ramp Time UP: 10S (±20%).
- Min Ramp Time DOWN: 20mS (±20%).
- Minimum Ramp Time DOWN: 10S (±20%).
- Dither Frequencies: Link Selectable 100Hz, 140Hz, 240Hz (All ±20%).
- Environmental: 'ENCAPSULATED' Printed Circuit Board.
- IP Rating for PCB Only: IP65 (Without Being Mounted In External Enclosure).
- IP rating for Housing: IP56 (Due to user accessibility of connector screw terminals.).
- Humidity: 90% Non Condensing.
- Storage temp.: 80 Deg C (Max).
- Working temp.: 60 Deg C (Max).
Housing Specification:
- Housing Type: 'Flanged' Bulkhead / Panel Mounting.
- Housing Material: High Impact Resistant Molded ABS.
- Housing Colour: Black.
- Surface Finish: Matt.
- Housing Thickness: 2mm (Mounting Flange and Face), 1.7mm All Internal Dividers.
- Base Dimensions: 112mm X 120mm.
- Rear Panel: Separate 'Self Locking' Rear Cover With.
- Wire entry: Via 7 X 'Slots' in rear panel support bar.
- Encapsulation: Flame Resistant, Black, Two Part Epoxy Resin.
Usage Features
The Dual Driver is designed for ease of application and use, offering several features that enhance its versatility and reliability:
- CE Compliance: Full CE compliance to present EMC directives, ensuring maximum operational potential and efficiency.
- Multiple Supply Voltages and Current Options: Configurable via internal PCB mounted links.
- Encapsulated Design: The main Printed Circuit Board is totally encased in a black flame-proof resin, making it impervious to external matter such as liquids. This provides IP65 protection for the PCB and IP56 for the housing (due to connector screw terminals).
- Robust Construction: 'Ruggedised' internal and external design suitable for 'Internal' or 'External' applications, including mobile, outdoor, aggressive environmental, and marine usage.
- Diagnostic LED Display: Front panel full unit status 'Diagnostic' LED display for easy troubleshooting.
- Remote 'Enable' or 'Emergency Stop' Input: For maximum system safety.
- Isolated Product Design: For improved safety and ease of application in difficult areas.
- User-Configurable Command Input: Choice of 0 to +/-5V, 0 to +/-10V, or 0 to +/-20mA signals.
- User-Definable Dither Frequency: Selectable at 100Hz, 140Hz, or 250Hz.
- Mounting: Bulkhead, wall, or panel mounting, rust-proof, high impact absorbing ABS molded enclosure, secured via 3 x 5mm fixings.
- Heavy-Duty Connectors: Two-part polarized screw terminal connectors for easy application.
- Add-On Option Sub-Boards: To enhance base characteristics and provide specialized functionalities.
Maintenance Features
The design incorporates features that simplify maintenance and ensure long-term reliability:
- Field-Tested Design: Unit comprises of field and time-tested and proven electronic circuit design.
- Over-Adjustment Protection: Potentiometers for 'I Min', 'I Max', and Ramp Generator adjustments are 20-turn varieties with mechanical end stop slipping clutches to protect them from over-adjustment.
- Diagnostic LEDs: Front panel LEDs indicate 'Power On', 'Emergency STOP', 'Output A ON', 'Output B ON', and '4-20mA Loop Fail', aiding in quick fault identification.
- Troubleshooting Guide: The manual provides a comprehensive troubleshooting guide for common issues, such as insufficient flow/pressure, lack of response to command signals, and output anomalies.
- Self-Locking Rear Cover: The rear panel is 'self-locking' and comes in unit packaging, to be fitted by the user once adjustments have been completed, ensuring secure enclosure.
Important Notes for Usage and Maintenance:
- Always read the information/data sheets thoroughly before starting.
- Ensure the unit supply voltage matches the valve coil voltage.
- Isolate the unit from all other equipment before any welding takes place.
- Check all connections for short circuits.
- Operate new systems at low pressure and with small command signals.
- Ensure the unit's supply voltage is correct, 'electrically clean', and stable.
- Operate within specified temperature ranges.
- Terminate unused wires/terminals safely to prevent shorting.
- NEVER arc weld or charge batteries with the driver unit connected.
- NEVER attempt to use the unit if unsure of connections or expected operation.
- NEVER use in areas where AC or DC coils have not been fully suppressed.
- NEVER use a power supply not rated for the required output current under full load.
- NEVER allow wires to or from the unit to short circuit.
- NEVER disconnect or connect wires unless the unit is isolated from the power supply.
- NEVER use the unit in temperatures exceeding specifications.
- For optimal performance, ensure the supply voltage is at the upper limit (e.g., 13.8 – 14VDC for 12V coils, 28 – 32VDC for 24V coils).
- Command signals should be accurately kept within the selected signal range and not exceed these levels by greater than 2% maximum to avoid output 'flipping' behavior.
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