Austin F Kelly

US Patent:

39784711, Aug 31, 1976

Filed:

Mar 26, 1975

Appl. No.:

5/562194

Inventors:

Austin T. Kelly - Morristown NJ

Assignee:

Weston Instruments, Inc. - Newark NJ

International Classification:

H03K 1320

US Classification:

340347NT

Abstract:

A measuring device such as a digital thermometer uses dual slope analog-to-digital converter techniques but elminates the usual need for a high precision voltage source. An input capacitor is connected through novel switching to the temperature responsive arm and the temperature insensitive arm of a resistance bridge, to the low precision voltage source and to the output of the integrator and detector amplifiers. The switching sequence is such that long term changes in the voltage source and in the amplifier offset and drift are cancelled out during measurement cycles, thereby providing highly accurate measurements without the usual need for an expensive high precision voltage source.

US Patent:

39582361, May 18, 1976

Filed:

Dec 18, 1974

Appl. No.:

5/534149

Inventors:

Austin T. Kelly - Morristown NJ

Assignee:

Weston Instruments, Inc. - Newark NJ

International Classification:

H03K 1320

US Classification:

340347NT

Abstract:

A dual slope analog-to-digital converter, which has an autozeroing circuit for cancelling out integrator and detector offset and drift, is additionally provided with a circuit for injecting a voltage of selected polarity and magnitude to offset the input voltage of the converter such that the input voltage can be measured with respect to a nonzero reference line.

US Patent:

43215300, Mar 23, 1982

Filed:

Jul 11, 1979

Appl. No.:

6/056729

Inventors:

Austin T. Kelly - Morris Plains NJ
Philip Emile - Roseland NJ
Alan H. Stolpen - Union NJ

Assignee:

Sangamo Weston, Inc. - Norcross GA

International Classification:

G01R 1508
G01R 1916

US Classification:

324115

Abstract:

A digital multimeter having a tone generating circuitry and operable in a tone mode of operation for providing an audible indication when a measured electrical characteristic has a predetermined relationship with a reference value. The audible indication may be provided when a voltage level exceeds a preselectable limit, such as 1 or 2 volts. Predetermined limits for resistance values may also be selected for actuation of the audible tone. The device may be utilized as a conventional multimeter when the tone mode is non-operative.

US Patent:

45203105, May 28, 1985

Filed:

Jun 18, 1982

Appl. No.:

6/389723

Inventors:

Austin T. Kelly - Morris Plains NJ
Alan H. Stolpen - Union NJ
Philip Emile - Roseland NJ

Assignee:

Sycon Corporation - Marion OH

International Classification:

G01R 1508
G01R 1702

US Classification:

324115

Abstract:

Circuitry for use in a voltage measurement and display device provides automatic function change for measurement of AC or DC voltages. Voltage measurement in a predetermined mode (DC, for example), is assumed. Upon detection of an input voltage component exceeding a predetermined threshold of the other mode, (AC, for example), the measurement function is changed to that other mode. Upon detection of a component in the other mode, in a range between the predetermined threshold and a second (preferably lower) threshold, an annunciator is activated to alert the user to the presence of the other mode (AC) voltage, for manual activation of a function-selecting switch if desired. Thus, in a specific embodiment, automatic function changeover is provided upon detection of AC components exceeding a predetermined threshold, along with activation of an AC annunciator. Alternatively, in the presence of low magnitude AC ripple voltage components on a DC voltage being measured, the annunciator is activated to attract the operator's attention, with measurement continuing in the DC function.