Electronic Design

Multi-Axis Servo Amps Revamp Automation Design

This all-digital motion-control architecture cuts costs up to 50% and makes designs easier with a library of software building blocks.

Fundamentally changing the way engineers design automation systems, Copley Controls' family of network-compatible all-digital servo amplifiers suit multi-axis motion control, slash system cost, and minimize complexity. The company believes its Accelnet technology, the basis of these amplifiers, is its most significant creation in 20 years of motion-control innovation. The technology is allied with the industry-standard CANopen networking protocol. The amplifiers work with freely available software building blocks from the Copley Motion Library (CML).

The Accelnet line's five versions operate from 55 V at 8 A peak to 180 V at 20 A peak. They provide sinusoidally commuted motor drive plus field-oriented motor control. Designed with solderless power and signal connections, they're built on pc-board-mounting packages that measure just 2.62 by 4.05 by 0.98 in. Communication is over a two-wire control-area network (CAN) bus.

Advanced carrier-cancellation modulation is used for maximum zero-crossing linearity as well as for ultra-low ripple current that occurs at twice the carrier pulse-width modulation frequency. Ripple frequency is 28 kHz. Current-loop bandwidth is 2.5 kHz. Each amplifier provides a 14-kHz current-loop update rate (17.4 µs) and a position and velocity loop update rate of 3.5 kHz (286 µs).

Accelnet servo amplifiers, available from stock up to four weeks, cost from $330 each in one- to nine-unit quantities based on current and voltage ratings.

Copley Controls Corp.

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