US 4,538,100 A · DC to AC inverter and motor control system

Abstract

This relates to a low cost reliable controller which may be used in conjunction with induction motors or, more generally, to generate AC power from a DC source. The system utilizes a microprocessor in combination with low cost parallel transistors to provide the control function. A feedback module monitors the actual rotor speed and conveys this information back to the microprocessor. A voltage boost module may be used in combination with the microprocessor and switching circuits to optimize the overall efficiency of the system. The microprocessor computes slip and controls the voltage drive in order to further optimize efficiency of the system as a function of motor speed. Both the footfeed voltage and boosted voltage are analog voltages and are applied to an A/D converter. The output of the A/D converter presents a digital representation of the footfeed voltage or boost voltage to the microprocessor.

Claims7

Dependent claims

A DC to AC inverter system, comprising:

microprocessing means;
a first plurality of counting means each coupled to said microprocessing means for receiving data therefrom and for generating a plurality of square wave signals;
a second plurality of driver means, each one of which is coupled to a different one of said first plurality of counting means for receiving the square wave signals generated thereby and deriving therefrom one phase of a multiphase AC signal;
and
first means coupled to said microprocessor means for varying the frequency of each phase of said multiphase signal by varying the contents of each of said first plurality of counting means associated with each of said second plurality of driver means.

2 more elements

Dependencies are inferred from the claim text.

DC to AC inverter and motor control system

Life of this patent

DC to AC inverter and motor control system

Life of this patent

Abstract

Claims7