Eddy Current

Currents induced in motor components from the
movement of magnetic fields. Eddy currents
produce waste heat and are minimized by
lamination of the motor poles and armature.

Dwell EEMAC

Dwell
The time spent in one state before moving to
the next. In motion control applications for
example, a dwell time may be programmed to
allow time for a tool change or part clamping
operation.

EEMAC
Acronym for Electrical and Electronic
Manufacturer's Association of Canada. Similar
to NEMA in the U.S.

dv/dt

The rate of change in voltage versus a rate of
change in time. Specially designed Resistor-
Capacitor networks can help protect the SCRs
from excessive dv/dt which can result from line
voltage spikes, line disturbances and circuit
configurations with extreme forward conducting
or reverse blocking requirements.

Dusttight DutyCycle

Dusttight
"Dusttight" means that a device is so
constructed so that dust will not enter the
enclosure case under specified test conditions.

DutyCycle
The relationship between the operating and rest
times or repeatable operation at different loads.

Dry Type (transformers)

A dry type transformer is one in which the
transformer core and coils are immersed in air
or other dry gas.