Kenneth A Stuart

US Patent:

56357737, Jun 3, 1997

Filed:

Aug 23, 1995

Appl. No.:

8/518237

Inventors:

Kenneth L. Stuart - Pasadena MD

Assignee:

Litton Systems, Inc. - Woodland Hills CA

International Classification:

H02J 900

US Classification:

307 66

Abstract:

According to the present invention, a high efficiency no-dropout uninterruptible power supply is presented which will provide desired UPS characteristics while reducing or eliminating undesirable characteristics. In particular, simultaneous improvements are achieved in the areas of switchover transfer response time, droop and transients, EMI generation, power efficiency and heat generation, size, weight, ease of waveshaping, and powerline frequency sensitivity. The invention utilizes dual concurrent feedback loops to control utility-backup power transfer and incorporates a novel method of synchronized AC output generation which allows zero-power switching and simple high-frequency waveshaping control.

US Patent:

41602889, Jul 3, 1979

Filed:

May 17, 1978

Appl. No.:

5/906706

Inventors:

Kenneth L. Stuart - Riviera Beach MD
William E. Baker - Frederick MD

Assignee:

Communications Satellite Corp. - Washington DC

International Classification:

H02M 114
H02M 3335

US Classification:

363 41

Abstract:

A regulated DC to DC power supply which minimizes input bus current changes caused by low frequency cyclical load variations is disclosed. The power supply includes a regulator connected to the input bus and controlled by a pulse width modulator. The regulator converts the DC voltage on the input bus to a higher, regulated DC voltage which is supplied to a variable load. A voltage feedback circuit is connected to the output of the boost converter and generates a control voltage which is supplied to the pulse width modulator to regulate the output voltage for variations in line voltage and load. The voltage feedback circuit includes an operational amplifier having a reference voltage supplied to a positive input terminal, and the output of the regulator supplied to a negative input terminal. A frequency response shaping network is connected between the output and the negative input terminal of the operational amplifier. An input bus current-sensing servo circuit is connected to sense current variations in the input bus and generate a control signal to the pulse width modulator to regulate the input current of the regulator.