Steven Thomas Swift

US Patent:

6392402, May 21, 2002

Filed:

Jul 30, 1998

Appl. No.:

09/126987

Inventors:

Steven Dennis Swift - Seattle WA

Assignee:

Fluke Corporation - Everett WA

International Classification:

G01R 1500

US Classification:

324132, 324115, 324142

Abstract:

An rms converter accommodates incoming signals of large crest factor by using an amplifier having a transfer function of non-uniform slope. The amplifier has a lower gain for larger signals. The output of the amplifier is converted to digital voltage values. The non-uniform gain of the amplifier is compensated for in digital calculations of the rms value. The invention produces accurate rms measurements by accurately measuring lower incoming signal voltages while still accommodating high peak voltages. The invention also reduces the dynamic range requirements for the analog to digital converter.

US Patent:

54184649, May 23, 1995

Filed:

Jul 26, 1993

Appl. No.:

8/097439

Inventors:

Steven D. Swift - Seattle WA

Assignee:

John Fluke Mfg. Co., Inc. - Everett WA

International Classification:

G01R 3102

US Classification:

324537

Abstract:

An improved open circuit detector for testing a thermocouple for an open circuit condition. The detector includes a generator for providing and sourcing a tone signal to the thermocouple, wherein the tone signal has a known frequency and amplitude. A monitor analyzes the amplitude of a particular frequency component of a tone signal across the thermocouple. If the amplitude of the particular frequency component exceeds a predetermined threshold, an output is provided for indicating an open circuit condition for the thermocouple.

US Patent:

44451113, Apr 24, 1984

Filed:

Sep 15, 1980

Appl. No.:

6/187442

Inventors:

Steven D. Swift - Seattle WA
Jonathan J. Parle - Seattle WA
David A. Gunderson - Everett WA

Assignee:

John Fluke Mfg. Co., Inc. - Everett WA

International Classification:

H03K 1302

US Classification:

340347CC

Abstract:

Bi-polar electronic signal converters, such as analog-to-digital or digital-to-analog converters, with a single polarity accurate reference source are disclosed. In one polarity direction, the accurate reference source is used in a conventional manner to transform the signal to be converted from one form (e. g. , analog) to the other form (e. g. , digital). In the other polarity direction, an inaccurate reference source is used in a similar conventional manner to convert the signal from one form to the other form. Periodically, the accurate and the inaccurate reference sources are compared to determine a correction multiplier. The correction multiplier is used during conversions using the inaccurate reference source to compensate for the inaccuracy of the inaccurate reference source.

US Patent:

59307455, Jul 27, 1999

Filed:

Apr 9, 1997

Appl. No.:

8/840086

Inventors:

Steven D. Swift - Seattle WA

Assignee:

Fluke Corporation - Everett WA

International Classification:

G01D 300

US Classification:

702190

Abstract:

A front-end architecture is provided for a measurement instrument having a single path for the input signal for conversion into digital samples. A signal conditioner may be coupled via a pair of test leads across a voltage source, current source, or component to develop an input signal. The input signal is provided to a sampling system, which comprises a sigma-delta converter followed by a decimation filter, which over-samples the input signal to produce a continuous stream of digital samples. The digital samples are provided to a set of digital extraction filters, each digital extraction filter having a structure and transfer function adapted for extracting a measurement parameter from the stream of digital samples. Parameter extraction is performed on a continuous basis so that the digital samples and the resulting digital measurement values arrive in a continuous stream. Extracted parameters include the d. c.

US Patent:

56989849, Dec 16, 1997

Filed:

Jan 30, 1996

Appl. No.:

8/594065

Inventors:

Erik R. Little - Seattle WA
Steven D. Swift - Seattle WA
Greg S. Gibson - Bothell WA

Assignee:

Fluke Corporation - Everett WA

International Classification:

G01R 3500

US Classification:

324601

Abstract:

An adaptive digital filter is provided to obtain improved measurement accuracy in an electronic instrument which has a front-end circuit for coupling to an input signal to be measured. An analog to digital converter converts the input signal received through the front-end circuit into a stream of measurement values during the measurement phase. The stream of measurement values are then provided to the adaptive digital filter which mathematically operates on them to remove the frequency response effects of the front-end circuit in a process of convolution in the time domain using a set of digital filter values obtained during the calibration phase. Because the frequency response requirements of the front-end circuit have been eased with the addition of the adaptive digital filter, a simpler front-end circuit with fewer components and with no need for manual adjustment may be employed in electronic instruments.

US Patent:

58049797, Sep 8, 1998

Filed:

May 13, 1997

Appl. No.:

8/855276

Inventors:

John M. Lund - Marysville WA
Steven Dennis Swift - Seattle WA

Assignee:

Fluke Corporation - Everett WA

International Classification:

G01R 2708

US Classification:

324713

Abstract:

A circuit for measuring alternating current (a. c. ) and direct current (d. c. ) in a conductor without breaking the conductor is provided. A modulated current source is coupled in parallel with a segment of the conductor to inject a test current. A synchronous demodulator is also coupled in parallel across the segment to separate the test voltage drop induced by the test current from the voltage drop due to the current in the conductor. The test voltage drop and the voltage drop are measured by a voltmeter and the resistance of the segment and the current flowing through the segment can then be calculated.

US Patent:

50936549, Mar 3, 1992

Filed:

May 17, 1989

Appl. No.:

7/353102

Inventors:

Steven D. Swift - Seattle WA
Roger E. Baker - Redmond WA

Assignee:

Eldec Corporation - Lynnwood WA

International Classification:

G09G 300

US Classification:

340781

Abstract:

A power supply system for controlling the drive voltages applied to a thin film electroluminescent (TFEL) display panel is disclosed. The system includes a power supply that generates the drive voltages to the TFEL display panel and causes it to emit light. A replaceable or resettable display voltage memory located adjacent the display panel provides the power supply with voltage information specific to the display panel. A feedback circuit measures the light emitted from the display panel. A balancing circuit controls multiple display voltages so that they have the proper relationship with respect to each other. The information from the display voltage memory and the feedback circuit is used by the power supply to control the output of the display voltages.

US Patent:

20160082526, Mar 24, 2016

Filed:

Dec 9, 2015

Appl. No.:

14/964183

Inventors:

Steven M. SWIFT - KENT WA, US
Luke Tyler SWIFT - KENT WA, US

International Classification:

B23C 5/10

Abstract:

A rotary cutting tool. The tool has a body with outside diameter (OD), and outer surface, and a longitudinal axis, a plurality of flutes, helical in some embodiments. Flutes include a narrow leading edge land portion with circular segment profile and having flute cutting edge portions along a substantially uniform circumferential location, with an eccentric relief margin rotationally rearward of the narrow leading edge land portions. Face portions are provided with face cutting edge portions, and with a first dish portion adjacent each of the cutting edge portions sloping inwardly and downwardly generally toward a central longitudinal axis at a first dish angle alpha (α) Corner blend portions extend from flute cutting edge portions to the face cutting edge portions. Corner blend portions are provided in a variety of profiles, including an embodiment wherein the profile of the corner blend portions are truncated before the segment of curvature becomes tangential to the face cutting edge portions. Large core diameters of cutting tools are provided, which gives high strength at when working with axial depths of cut of about three times outside tool diameter or less.