operate at speeds many times higher than that of any other 60-Hz electric motor. When operated without
load, universal motors tend to run away, speed being limited only by windage, friction, and commutation. Therefore, large universal motors are nearly always connected directly to a
load to limit speed. On portable tools such as electric saws, the
load imposed by the gears, bearings, and
cooling fan is sufficient to hold the no-
load speed down to a safe value. With a universal motor, speed control...
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