User Manual SCA-LE-30-03
ElectroCraft
®
E-Mail: [email protected] www.electrocraft.com May 2009
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Driver
Is the electronics which convert step and direction inputs to high power currents and
voltages to drive a step motor. The step motor driver is analogous to the servomotor
amplifier's logic.
Encoder
Is a feedback device which converts mechanical motion into electronic signals. The most
commonly used, rotary encoders, output digital pulses corresponding to incremental angular
motion. For example, a 1000-line encoder produces 1000 pulses every mechanical
revolution. The encoder consists of a glass or metal wheel with alternating transparent and
opaque stripes, detected by optical sensors to produce the digital outputs.
Efficiency
The ratio of power output to power input.
Feedback
It is a signal which is transferred from the output back to the input for use in a closed loop
system.
Four quadrants
Refers to a motion system which can operate in all four quadrants; i.e., velocity in either
direction and torque in either direction. This means that the motor can accelerate, run, and
decelerate in either direction.
Inductance
The electrical equivalent to mechanical inertia; that is, the property of a circuit, which has a
tendency to resist current flow when no current is flowing, and when current is flowing has a
tendency to maintain that current flow.
NTC - Negative Temperature Coefficient
A negative temperature coefficient thermistor is used to detect and protect a motor winding
from exceeding its maximum temperature rating it is also used in a servo amplifier.
Resistance of the device decreases with an increase in temperature.
