Abstract: An uninterruptible power supply including a transformer having a first input winding normally coupling an inverter AC source with a critical AC load, which transformer also includes a second input winding operable to supply power from a bypass source to the load in the event of malfunction of the inverter circuit. The inverter is of the four-quadrant pulse-width-modulated type, thereby to permit recharging of the battery which serves as the DC source to the inverter. An inductance is provided for varying the phase relationship between a utility voltage source and the inverter voltage to produce minimum real inverter current and the "break-even" operating conduction, and a step-up device is provided for increasing the utility voltage to further minimize the break-even inverter current required during normal operation, and to maximize the through-put efficiency.
Type:
Grant
Filed:
February 15, 1985
Date of Patent:
June 16, 1987
Assignee:
Exide Electronics Corporation
Inventors:
William J. Raddi, Robert W. Johnson, Jr., John G. Tracy, Blazej W. Sonnenberg