Rockwell Automation SA3100 AutoMax Distributed Power System User Manual
Page 49
Glossary
A-5
dual port memory: memory accessible to two or more microprocessors. The UDC
module has dual port memory that can be accessed by the UDC microprocessor and
AutoMax Processors in the rack.
duty cycle: a description of the variation of load with time.
dv/dt: the change in voltage versus the change in time.
dynamic braking: see braking.
EMF: electromotive force; voltage or potential difference. In DC adjustable speed
drives, voltage applied to the motor armature from the power supply is the EMF, and
the opposing voltage generated by the speed of the motor is the counter-EMF
(CEMF).
E-stop: emergency stop.
feeder: the power lines “feeding” power to drive; one feeder may send power to more
than one drive.
fiber (fiber-optic cabling): a single optical element which is composed of a core and a
cladding.
fiber optics: light pulse transmission through optical fibers.
field (winding): a stationary electrical winding of a DC motor; wired in parallel (shunt)
or in series with the armature.
field control: method of controlling the speed and torque of a DC motor by means of
a change in the magnitude of the field current.
field minor loop (FML): see loop.
field reversing: one method of producing reverse torque for regeneration or reverse
rotation; it is accomplished by changing the direction of current through the motor
field, which reverses the polarity of the motor CEMF to account for generator action.
field weakening: the action of reducing the current applied to a DC motor shunt field.
This action weakens the strength of the magnetic field while decreasing the available
motor torque.
firing angle: a point in time where the SCR is triggered into conduction.
flash (memory): a type of memory that does not require battery back-up. Used in the
UDC module.
FML (field minor loop): see loop.
four-quadrant operation: See quadrant, Form D - Type IV.
full-load current: the armature current of a DC motor at full torque rating at full field.
full-load speed: motor base speed.