Khanh Van Le

US Patent:

52185222, Jun 8, 1993

Filed:

Mar 3, 1992

Appl. No.:

7/845074

Inventors:

Thomas K. Phelps - Torrance CA
Khanh T. Le - Fountain Valley CA
Gilbert I. Cardwell - Palos Verdes Peninsula CA

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

H02M 3337

US Classification:

363124

Abstract:

An unregulated D. C. input voltage (V. sub. IN) is processed by a high power chopper (34,36) to produce a first chopped signal having the same voltage as the input (V. sub. IN), and by a low power chopper (56,58) to produce a second chopped signal in synchronism with and having a lower voltage than the first chopped signal. The first and second chopped signals are algebraically combined by transformers (52,54) to produce an A. C. output signal which may be converted to D. C. (V. sub. OUT). The second chopped signal may be controlled to have the same polarity relative to the first chopped signal in which case the voltages add to increase the output voltage (V. sub. OUT), or to have the opposite polarity relative to the first chopped signal in which case the voltages subtract to decrease the output voltage (V. sub. OUT). The periods of addition and subtraction are alternated within the period of the first chopped signal. The ratio of addition and subtraction of the second chopped signal may be varied to adjust the ratio of output voltage to input voltage over a wide range.

US Patent:

20180056116, Mar 1, 2018

Filed:

Aug 27, 2016

Appl. No.:

15/249348

Inventors:

KHANH TRINH LE NGUYEN - San Gabriel CA, US

International Classification:

A63B 22/00
A63B 1/00
A63B 23/12
A63B 21/068
A63B 21/00
A63B 3/00

Abstract:

A collapsible free standing exercise apparatus for performing multiple body weight exercises is disclosed. The collapsible free standing exercise apparatus comprises a pair of hollow vertical bars separated at a predetermined distance via a connector bar assembly removably fastened at a lower portion of each hollow vertical bar. A first handle bar is removably fastened to each vertex joint on each pair of hollow vertical bars and a second handle assembly removably fastened between each pair of hollow vertical bars at a predetermined position via a support section disposed at distal ends of the second handle bar. A method of fixing the collapsible free standing exercise apparatus for use is also disclosed.