The LEO digital regulator from Re S.p.A. is an extremely versatile and reliable solution for managing the torque and tension of electromagnetic powder brakes and clutches. Built on advanced microprocessor technology, the LEO unit provides the high precision required for sophisticated winding and unwinding processes in the paper, plastic, and textile industries.

Versatile Control Architecture

The LEO regulator is designed to adapt to various system requirements, offering three distinct operational modes:

• Closed-loop Current Regulator: Functions as a high-precision power supply that keeps the output current constant regardless of temperature fluctuations or resistance changes in the brake coil.
• Open-loop Tension Control: When paired with an external sonar (ultrasonic) sensor, LEO calculates the reel diameter and automatically adjusts the torque to maintain consistent tension as the roll size changes.
• Closed-loop Tension Control: Utilizing a Proportional-Derivative (PD) algorithm, the unit receives real-time feedback from load cells or dancer rollers to provide dynamic, ultra-stable tension management.

Innovative Antiresidual Function

A common challenge with electromagnetic powder brakes is the presence of residual magnetism, which can cause "cogging" or excessive torque at very low settings. The LEO features a specialized antiresidual function that actively cancels this magnetism. This allows the system to operate smoothly even in low-torque applications, which is essential for processing thin or delicate materials like foil and light plastic films.

Key Features

• Compact Footprint: Its small dimensions allow for easy integration into crowded electrical cabinets via standard DIN rail mounting.
• High Precision: Digital processing ensures repeatable performance and easy parameterization.
• Reliability: Robust electronic design tailored for the harsh electrical environments of industrial production lines.
• User-Friendly Setup: Simple interface for setting PID parameters, current limits, and sensor calibration.

Typical Applications

• Printing Presses: Maintaining web tension for consistent print registration.
• Laminating Machines: Ensuring uniform bonding of layers through precise tension control.
• Slitter Rewinders: Managing individual reel tension during high-speed cutting and rewinding.
• Textile Production: Handling delicate yarns and fabrics without stretching or breakage.