Robert Carl Erickson

US Patent:

6900998, May 31, 2005

Filed:

May 30, 2003

Appl. No.:

10/452570

Inventors:

Robert W. Erickson - Boulder CO, US
Osama A. Al-Naseem - Safat, KW
Lee Jay Fingersh - Westminster CO, US

Assignee:

Midwest Research Institute - Kansas City MO

International Classification:

H02M005/22
H02P009/48

US Classification:

363159, 290 44

Abstract:

A system and method for efficiently capturing electrical energy from a variable-speed generator are disclosed. The system includes a matrix converter using full-bridge, multilevel switch cells, in which semiconductor devices are clamped to a known constant DC voltage of a capacitor. The multilevel matrix converter is capable of generating multilevel voltage wave waveform of arbitrary magnitude and frequencies. The matrix converter can be controlled by using space vector modulation.

US Patent:

7148669, Dec 12, 2006

Filed:

Feb 2, 2004

Appl. No.:

10/770018

Inventors:

Dragan Maksimovic - Boulder CO, US
Jingquan Chen - Sunnyvale CA, US
Aleksandar Prodic - Toronto, CA
Robert W. Erickson - Boulder CO, US

Assignee:

The Regents of the University of Colorado, a body corporate - Boulder CO

International Classification:

G05F 1/56

US Classification:

323283, 323222

Abstract:

The present invention provides a method for producing a controlled output voltage for a switching power converter under current control using pulse width modulation, the switching power converter including a predictive digital current-mode controller and a digital pulse width modulator. The current control results in an unstable output voltage, and the pulse width modulation method is selected to eliminate the instability of the output voltage.

US Patent:

7337554, Mar 4, 2008

Filed:

Oct 17, 2005

Appl. No.:

11/251714

Inventors:

Robert William Erickson - Minneapolis MN, US

International Classification:

F26B 7/00

US Classification:

34396

Abstract:

A technique for end-grain creation is employed for obtaining rapid and uniform drying of lumber while simultaneously reducing warp. The stability-kerfing responsible for the improved drying of the lumber decreases the edgewise bending strength by less than ten percent, a loss readily recovered due to the ability of stability-kerfing to achieve lower and more uniform moisture contents than those realized in the contemporary drying of lumber. The improved moisture condition provided by the stability-kerfing also fosters future dimensional stability at the time of entry into the marketing stream compared to that for contemporary lumber. The required stability-kerfing is easily accomplished by the specialized implementation of existing saw equipment and associated technology into the contemporary processing lines.

US Patent:

7987614, Aug 2, 2011

Filed:

Apr 7, 2005

Appl. No.:

11/100710

Inventors:

Robert W. Erickson - Minneapolis MN, US

International Classification:

F26B 19/00

US Classification:

34396, 34518, 34381, 34 90, 34210, 34218, 100 50, 52641, 52 7912, 144347, 2972841, 2972844, 705 14, 264255, 264135

Abstract:

The present invention relates to an apparatus and processing method for drying lumber, for example two-by-four studs in an environment in a kiln in a manner to avoid warping, including crook, bow, cup and twist. The lumber pieces are stacked in a normal manner with stickers for providing air flow between courses of the lumber pieces, and the stack is dried while a horizontal force is provided to the respective courses of lumber in the stack to hold the individual pieces of lumber in edge to edge contact throughout the drying, equalizing, conditioning and cooling process for first drying of lumber, redrying of lumber or in a treatment process for removing warp from previously dried lumber. A vertical force comprising a weight or other force generating device can be also applied to the stack of lumber to augment the overall reduction in warpage if so evidenced.

US Patent:

20120215216, Aug 23, 2012

Filed:

Dec 21, 2011

Appl. No.:

13/334041

Inventors:

Daniel Friedrichs - Aurora CO, US
Robert Erickson - Boulder CO, US
James Gilbert - Boulder CO, US

Assignee:

The Regents of the University of Colorado, a body corporate - Denver CO

International Classification:

A61B 18/00

US Classification:

606 38

Abstract:

An electrosurgical generator may reduce unintended tissue damage by improving regulation of output power. The electrosurgical generator may control the power during a cycle, and react to a change in power if arcing occurs. Voltage sources, especially, demonstrate the tendency to have large, uncontrolled power excursions during normal electrosurgical use. The magnitude of the power excursions may be dependent on various factors. An exemplary electrosurgical generator control scheme reduces or minimizes the thermal spread by accurately supplying the specified power within a few cycles. Additionally, fast and accurate regulation provided by the constant voltage mode reduces or minimizes unintentional tissue charring. Thus, reduced thermal spread and charring should result in better surgical outcomes by reducing scarring and decreasing healing times. An electrosurgical generator controller may be configured to control both a DC-DC buck converter and a DC-AC boost inverter based in part on electrical parameters of the electrosurgical generator.

US Patent:

20140035255, Feb 6, 2014

Filed:

Aug 5, 2013

Appl. No.:

13/958707

Inventors:

Robert Allen Erickson - Minneapolis MN, US

International Classification:

B62K 21/02

US Classification:

280279, 298971

Abstract:

A bicycle apparatus with interchangeable front fork is disclosed. The bicycle comprises a frame and a quick release assembly for securing the removable front fork attachment assembly to the bicycle frame's head tube. The interchangeable front fork attachment assembly and quick release assembly allows for the quick interchanging of front fork with varying attachments which utilize different methods to achieve motion.

US Patent:

46775390, Jun 30, 1987

Filed:

May 7, 1986

Appl. No.:

6/860405

Inventors:

Robert W. Erickson - Boulder CO
Iftikar A. Khan - Lalazar Colony, PK

Assignee:

University Patents, Inc. - Westport CT

International Classification:

H02M 7538

US Classification:

363132

Abstract:

A dc to three phase ac switched mode converter is described wherein a six switch bridge is provided to interconnect the dc source to a three-phase load. A plurality of dc sources are described, each of which employs an inductor/capacitor combination for energy storage, which stored energy is subsequently applied to the output load. The stored energy is delivered by connecting the capacitor across two legs of the three-phase load, while assuring that the third leg is invariably short-circuited back upon itself. As a result, three of the six switches in the bridge are closed at any instant to prevent any current interruption in the load.

US Patent:

48292320, May 9, 1989

Filed:

Sep 2, 1988

Appl. No.:

7/239812

Inventors:

Robert W. Erickson - Boulder CO

Assignee:

General Motors Corporation - Detroit MI

International Classification:

G05F 146

US Classification:

323290

Abstract:

A nonlinear resonant switch for power conversion devices and a converter using the switch are described. The switch optimizes converter efficiency by switching only when current is zero and by limiting the peak current to a value near that provided by conventional PWM converters. A nonlinear reactor having a winding in series with the switch and a tank circuit is biased to saturation at low currents but is driven into an unsaturated condition by high currents so that a resultant high series inductance mitigates further current increase. Several converter topologies incorporating this improvement are shown.