| 摘要 |
Practically ideal electrical resonance is employed to soley provide armature power, and stator power if desired, to run DC motors. A practically ideal parallel resonant tank circuit (PIPRC) is used wherein the quotient of the "tank current" divided by the "line current" (called the "quality" or "Q" of the tank) is (1) greater than one, (2) large enough to allow the percent efficiency of the electric motor to be equal to or greater than 95%, and (3) removes enough back emf or enough of the influence thereof so that criteria (1) and (2) can be realized throughout the entire operating range of the motor. Only one PIPRC is needed for a DC motor. Recontrolling and/or redesigning is done for two reasons. First, since DC motors change effective impedance, because of back emf variations, when their speed changes, controls are implemented to ensure that the tank circuit always meets criterion (3), and therefore criteria (1) and (2), thereby maintaining a PIPRC, regardless of how frequent or to what degree speed is changed. Secondly, this first control has the effect of negating the normal ability of a D.C. motor to draw different currents for driving different loads. Therefore, the way current is supplied to the motor is also recontrolled.
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