The current state of the art with respect to electric motor drives involves the use of a power source that provides electrical energy to switch-mode circuitry, most typically in the form of a half-bridge or a full H-bridge, that drives an electric motor using pulse width modulation control signals at a specified duty cycle and frequency controlling the speed and/or mechanical energy output of the electric motor.
An electric motor converts electrical energy into mechanical energy to drive a load. The current state of the art is the use of a power source to supply electrical energy to an electric motor to produce mechanical energy by using switch-mode circuitry with a switch-mode controller that regulates the pulse width modulation duty cycle of the electrical energy supplied to the electric motor. When the control signal for the switch-mode circuitry is in the “off” or inactive portion of the duty cycle, electrical energy that could be available is directed to ground or is otherwise unused. Therefore, what is needed in the art of electric motor drives is a way of recapturing the electrical energy that is unused during the “off” or inactive portion of the duty cycle.
The approaches described in this section are approaches that could be pursued but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualifies as prior art merely by virtue of inclusion in this section.