Quiet drive gets servo performance out of steppers

The Canadian motion control specialist Agile Systems has developed a sensorless drive system which, it claims, provides servo-like performance from stepper motors. The Silentstep drive incorporates a patent-pending sensorless commutation technology, said to boost motor speed and torque, while cutting noise levels by up to 75%.

Unlike conventional open-loop stepper systems which can stall when over-accelerated or when torque demand is irregular, the new drive includes stall detection and prevention and can accelerate and decelerate at maximum torque without losing position. The drive can be used to improve the performance of existing stepper installations, reducing mechanical resonance and noise levels. Alternatively, in new installations, it allows designers to build efficient, closed-loop positioning systems with simple, low-cost steppers. It can allow smaller motors to be used, thus saving space and costs.

The Silentstep, available in the UK from LG Motion, has a 15-75V DC input and a 7A peak current rating. There are inputs for differential pulse and direction. Windows software is provided to close the motor current loop and determine the no-load servo parameters. The software can also be used in a virtual mode to access a help system. Evaluation kits are available to explore the drive`s potential.