Search results
Results From The WOW.Com Content Network
The motor speed varies as a non-linear function of load torque and armature current; current is common to both the stator and rotor yielding current squared (I^2) behavior [citation needed]. A series motor has very high starting torque and is commonly used for starting high inertia loads, such as trains, elevators or hoists. [ 2 ]
72 - DC Circuit Breaker; 73 - Load-Resistor Contactor; 74 - Alarm Relay; 75 - Position Changing Mechanism; 76 - DC Overcurrent Relay; 77 - Telemetering Device, Speed Sensor; 78 - Phase Angle Measuring or Out-of-Step Protective Relay; 78V - Loss of Mains; 79 - AC Reclosing Relay / Auto Reclose; 80 - Liquid or Gas Flow Relay; 81 - Frequency Relay ...
A reference designator unambiguously identifies the location of a component within an electrical schematic or on a printed circuit board.The reference designator usually consists of one or two letters followed by a number, e.g. C3, D1, R4, U15.
Fiber optic current sensor, using an interferometer to measure the phase change in the light produced by a magnetic field. Rogowski coil, electrical device for measuring alternating current (AC) or high speed current pulses. Giant Magnetoresistance(GMR): Magnetic field sensor suitable for AC & DC Current with higher accuracy than Hall Effect ...
Direct torque control (DTC) is one method used in variable-frequency drives to control the torque (and thus finally the speed) of three-phase AC electric motors.This involves calculating an estimate of the motor's magnetic flux and torque based on the measured voltage and current of the motor.
A motor requiring a DC power supply for operation is termed a DC motor. DC motors are widely used in control applications like robotics, tape drives, machines and many more. Separately excited DC motors are suitable for control applications because of separate field and armature circuit. [1] Two ways to control DC separately excited motors are ...
In vector control, an AC induction or synchronous motor is controlled under all operating conditions like a separately excited DC motor. [21] That is, the AC motor behaves like a DC motor in which the field flux linkage and armature flux linkage created by the respective field and armature (or torque component) currents are orthogonally aligned such that, when torque is controlled, the field ...
When an electric motor, AC or DC, is first energized, the rotor is not moving, and a current equivalent to the stalled current will flow, reducing as the motor picks up speed and develops a back EMF to oppose the supply. AC induction motors behave as transformers with a shorted secondary until the rotor begins to move, while brushed motors ...