David G Hiltner

US Patent:

6674026, Jan 6, 2004

Filed:

May 10, 2002

Appl. No.:

10/143143

Inventors:

David F. Hiltner - Beaverton OR

Assignee:

Tektronix, Inc. - Beaverton OR

International Classification:

H01H 900

US Classification:

200 4, 200294, 200296

Abstract:

A rear-mount integrated rotary encoder comprises a mechanical portion and a printed circuit board portion. The mechanical portion of a rear mount integrated rotary encoder comprises a housing including a bushing for receiving one end of a rotatable shaft. The rotatable shaft passes through an open front portion of the housing and is mechanically connected to exposed rotatable circuit contacting members. The printed circuit board portion has an encoder contact pattern formed thereon. The printed circuit board has an area larger than the cross sectional area of the housing. The encoder contact pattern surrounds (or is at least concentric with respect to) an aperture in the circuit board. The rotatable shaft of the rotary encoder is passed through the aperture such that the rotatable circuit contacting members contact the encoder contact pattern on the circuit board. An elastomeric button is mounted on the front surface of the circuit board and surrounds the shaft of the rotary encoder to provide a spring-like action. The rotatable shaft is keyed to allow movement orthogonal to the plane of the circuit board while preventing rotation of the knob with respect to the rotatable shaft.

US Patent:

6944559, Sep 13, 2005

Filed:

Sep 12, 2003

Appl. No.:

10/661309

Inventors:

David F. Hiltner - Beaverton OR, US

Assignee:

Tektronix, Inc. - Beaverton OR

International Classification:

G06F019/00
H02H003/00

US Classification:

702 67, 327 7611, 361 1, 702 65, 702 70

Abstract:

A signal acquisition instrument, such as an oscilloscope, having an input stage that is referenced to a user's ground is disclosed. Information gathered by the input stage is stored in a storage element powered by a floating power supply that is referenced to the user's ground. After storage, the storage element is disconnected from the floating power and from the user's ground and switched to a power supply referenced to the remainder of the system. FET switching is beneficial, and information can be stored either in an analog format or in a digital format.

US Patent:

8471746, Jun 25, 2013

Filed:

Jul 8, 2011

Appl. No.:

13/179320

Inventors:

David F. Hiltner - Beaverton OR, US

Assignee:

Tektronix, Inc. - Beaverton OR

International Classification:

H03M 1/82

US Classification:

341152, 341143, 341155

Abstract:

A digital-to-analog converter includes first and second pulse modulators to generate first and second pulse modulated signals in response to first and second digital values, a third pulse modulator to generate a third pulse modulated signal in response to a third digital value, and a switch/filter circuit to generate an analog signal by combining the first and second pulse modulated signals in response to the third pulse modulated signal. The first and second pulse modulated signals may be low-pass filtered before being combined. In some embodiments, the third digital value may be incremented in a single direction between transitions of the first and second digital values. In some other embodiments, the third digital value may be incremented in opposite directions between alternating transitions of the first and second digital values.

US Patent:

20130033239, Feb 7, 2013

Filed:

Aug 4, 2011

Appl. No.:

13/197999

Inventors:

David F. HILTNER - Beaverton OR, US

Assignee:

TEKTRONIX, INC. - Beaverton OR

International Classification:

G05F 5/00

US Classification:

323208

Abstract:

Embodiments of the invention include an electronic load having variable reactive load capability and techniques for controlling and/or modeling a reactive component in a load. The electronic load can include a user interface through which a latency value is received from a user. A delay is created based on the latency value between the time that a variable of the input signal is sensed and the time that a variable of the input signal is driven to a new value, thereby simulating a reactive component in the electronic load based on the created delay. In one example embodiment, the driven variable can be stepped after the created delay to produce an approximation of a capacitive or inductive element. In another example embodiment, the driven variable can be slewed during the delay period using an arbitrary waveform generator, thereby more accurately simulating the reactive component.

US Patent:

42800919, Jul 21, 1981

Filed:

Oct 29, 1979

Appl. No.:

6/089067

Inventors:

David F. Hiltner - Portland OR

Assignee:

Tektronix, Inc. - Beaverton OR

International Classification:

G05F 144

US Classification:

323315

Abstract:

A variable current source having a programmable current-steering network is provided in which a plurality of field-effect transistors both provide current switching and form an integral part of the current source. This is accomplished by switching the field-effect transistors into and out of the feedback loop of a voltage follower, which in turn is connected to a current-setting resistor. Reference voltage for the current-setting resistor is provided by a variable voltage generator. The field-effect transistors are switched by means of a programmable digitally-switched bias generator circuit.

US Patent:

20140100822, Apr 10, 2014

Filed:

Oct 9, 2012

Appl. No.:

13/647939

Inventors:

- Beaverton OR, US
David F. Hiltner - Beaverton OR, US

International Classification:

G06F 15/00

US Classification:

702190, 702189

Abstract:

Embodiments of the invention include methods and instruments for generating covariance and correlation values of two or more signals. The covariance or correlation values are used to compare intervals of interest of the two signals and to produce trigger events based on similarities between the two signals. A reference signal is digitized and stored, and then used as a reference when comparing to a real-time input signal. Mean values of the input signal and the previously stored reference signal are generated so that suitable covariance and correlation values can be generated. Threshold detectors detect when the covariance value and/or the correlation value exceed certain thresholds, which can cause the test and measurement instrument to be triggered.