Energy saving motor controller

In a multi-phase motor controller for controlling voltage and power expended by a multi-phase motor producing motor voltage and motor current, a control circuit for controlling the voltage and power expended by said multi-phase motor, said control circuit comprising:

• a plurality of sensing means, one for each phase of said multi-phase controller, for detecting a phase angle difference between said motor voltage and said motor current for each phase individually;
• a plurality of pairs of silicon-controlled rectifiers, one pair for each phase of said multi-phase motor;
• and
• trigger means, one for each phase of said multi-phase motor, connected to each said sensing means, and responsive to said detected phase angle difference as detected by said plurality of sensing means for providing corresponding properly timed gate pulses to corresponding ones of said plurality of pairs of silicon-controlled rectifiers, respectively;
• whereby said multi-phase motor controller controls the voltage and power expended by any said multi-phase motor, regardless of type, without internal modification or connection to the multi-phase motor.

A multi-phase motor controller for controlling voltage and power expended by a multi-phase motor producing motor voltage and motor current, said controller adapted for external connection with said motor and comprising:

• a plurality of sensing means, one for each phase of said multi-phase motor controller, for detecting respective phase angle differences between said motor voltage and said motor current for each phase individually;
• summation circuit means for developing a summation of the phase angle differences;
• a feedback amplifier connected to said summation circuit means for comparing the summation of said phase angle differences with a desired phase angle difference so as to generate a feedback control signal;
• and
• control means connected to said feedback amplifier, and responsive to said feedback control signal for controlling the voltage and power expended by said multi-phase motor in accordance therewith;
• said controller further comprising stabilizing means connected between said sensing means and said feedback amplifier, and responsive to a lagging phase angle produced by said mutli-phase motor for providing a leading phase angle to compensate therefor;
• whereby said multi-phase motor controller controls the voltage and power expended by any said multi-phase motor, regardless of type, without internal modification or connection to the multi-phase motor.