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An electronic speed control follows a speed reference signal (derived from a throttle lever, joystick, or other manual input) and varies the switching rate of a network of field effect transistors (FETs). [1] By adjusting the duty cycle or switching frequency of the transistors, the speed of the motor is changed. The rapid switching of the ...
Inrush current, input surge current, or switch-on surge is the maximal instantaneous input current drawn by an electrical device when first turned on. Alternating-current electric motors and transformers may draw several times their normal full-load current when first energized, for a few cycles of the input waveform.
A motor controller is a device or group of devices that can coordinate in a predetermined manner the performance of an electric motor. [1] A motor controller might include a manual or automatic means for starting and stopping the motor, selecting forward or reverse rotation, selecting and regulating the speed, regulating or limiting the torque, and protecting against overloads and electrical ...
Motor control centers are usually used for low voltage three-phase alternating current motors from 208 V to 600 V. Medium-voltage motor control centers are made for large motors running at 2300 V to around 15000 V, using vacuum contactors for switching and with separate compartments for power switching and control. [3]
Further increase in speed begins and motor reaches its full rated speed. At this point the "soft start" is ended and motor can work under full load. The autotransformer is no longer required and is de-energized by opening switch 1. The motor is supplied directly from the three-phase network. To stop the motor, switch 3 is opened.
At this point in the cycle, the supply current will be zero, and therefore the average motor current will always be higher than the supply current unless the percentage on time is 100%. At 100% on time, the supply and motor current are equal. The rapid switching wastes less energy than series resistors.
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A motor soft starter is a device used with AC electrical motors to temporarily reduce the load and torque in the powertrain and electric current surge of the motor during start-up. This reduces the mechanical stress on the motor and shaft, as well as the electrodynamic stresses on the attached power cables and electrical distribution network ...