User Manual SCA-LE-30-03
ElectroCraft
®
E-Mail: [email protected] www.electrocraft.com May 2009
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Closed loop
This is broadly applied term, relating to any system in which the output is measured and
compared to the input. The output is then adjusted to reach the desired condition. In motion
control, the term typically describes a system utilizing a velocity and/or position transducer
to generate correction signals in relation to desired parameters.
Cogging
A term used to describe non-uniform angular velocity. Cogging appears as jerkiness,
especially at low speeds.
Continuous rated current
The maximum allowable continuous current a motor can handle without exceeding the
motor temperature limits
Continuous stall torque
Is the amount of torque at zero speed, which a motor can continuously deliver without
exceeding its thermal rating. To determined by applying DC current through two windings
with locked rotor, while monitoring temperature. It’s specified with motor windings at
maximum rated temperature and 25 °C ambient temperature, motor mounted to a heat sink.
Refer to individual specs for heat sink size.
Controller
A term describing a functional block containing an amplifier, power supplies, and possibly
position-control electronics for operating a servomotor or step motor.
Demag current
The current level at which the motor magnets will start to be demagnetized. This is an
irreversible effect, which will alter the motor characteristics and degrade performance.
Drive
It‘s an electronic device that controls torque, speed and/or position of an AC or brushless
motor. Typically a feedback device is mounted in or on the motor for closed-loop control of
velocity and position.
