Karl P Scheller

US Patent:

7046000, May 16, 2006

Filed:

Nov 17, 2004

Appl. No.:

10/989433

Inventors:

Takashi Hara - Ichinomiya, JP
Kazuhiro Kamiya - Kariya, JP
Kenichi Taguchi - Toyota, JP
Toshiyuki Matsuo - Takahama, JP
Takayoshi Tsuzuki - Toyota, JP
Glenn Forrest - Bow NH, US
Karl Scheller - Bow NH, US
Ravi Vig - Bow NH, US

Assignee:

Aisin Seiki Kabushiki Kaisha - Kariya
Allegro MicroSystems Inc. - Worcester MA

International Classification:

G01B 7/30

US Classification:

32420725

Abstract:

Disclosed is a rotation detecting sensor suitable for use under a vibration-abundant condition as e. g. a sensor disposed in an automobile body for detecting rotation of an engine or ABS. The sensor includes a detecting element for detecting rotation of a rotary body as a change in a magnetic flux and outputting a signal and an integrated circuit for processing the amplified signal into a pulse corresponding to the detected rotation of the rotary body. The signal processing includes an initialization such as a gain adjustment for obtaining an appropriate gain for use in the subsequent process of conversion of the amplified signal to the pulse. According to this invention, a re-initialization is effected to obtain a new initial value such as a new gain if the previously effected initialization is determined inappropriate.

US Patent:

7053674, May 30, 2006

Filed:

Dec 13, 2004

Appl. No.:

11/010704

Inventors:

Hernan D. Romero - Buenos Aires, AR
Jay M. Towne - Newbury NH, US
Karl Scheller - Bow NH, US

Assignee:

Allegro Microsystems, Inc. - Worcester MA

International Classification:

G11C 27/02

US Classification:

327 94, 327 62

Abstract:

A track-and-hold peak detector circuit, which can operate at low input signal frequencies, includes a capacitor to hold a peak voltage of the input signal and logic circuitry that reduces an effect of leakage current into or out of the capacitor, and therefore, provides protection against self-switching of an output signal of the peak detector circuit.

US Patent:

7199579, Apr 3, 2007

Filed:

Mar 8, 2004

Appl. No.:

10/795930

Inventors:

Karl Scheller - Bow NH, US
Gerardo Monreal - Buenos Aires, AR
Jason Stauth - Berkley CA, US

Assignee:

Allegro Microsystems, Inc. - Worcester MA

International Classification:

G01B 7/14

US Classification:

32420726

Abstract:

A proximity detector includes a fine DAC and a coarse DAC, outputs of which are summed to provide a tracking signal for tracking a magnetic field signal. The proximity detector provides two mode of operation. In a first mode of operation the coarse and fine DACs operate in combination as one higher order DAC. In a second mode of operation, the coarse DAC is provided with one or more extra counts, allowing the tracking signal to move more rapidly to track a rapidly changing magnetic field signal. In another embodiment, the proximity detector also includes an offset circuit for bringing at least one of the magnetic field signal and the tracking signal towards the other one of the magnetic field signal and the tracking signal.

US Patent:

7368904, May 6, 2008

Filed:

Feb 12, 2007

Appl. No.:

11/673728

Inventors:

Karl Scheller - Bow NH, US
Gerardo Monreal - Buenos Aires, AR
Jason Stauth - Berkley CA, US

Assignee:

Allegro Microsystems, Inc. - Worcester MA

International Classification:

G01B 7/14

US Classification:

32420726

Abstract:

A proximity detector includes a fine DAC and a coarse DAC, outputs of which are summed to provide a tracking signal for tracking a magnetic field signal. The proximity detector provides two mode of operation. In a first mode of operation the coarse and fine DACs operate in combination as one higher order DAC. In a second mode of operation, the coarse DAC is provided with one or more extra counts, allowing the tracking signal to move more rapidly to track a rapidly changing magnetic field signal. In another embodiment, the proximity detector also includes an offset circuit for bringing at least one of the magnetic field signal and the tracking signal towards the other one of the magnetic field signal and the tracking signal.

US Patent:

7518414, Apr 14, 2009

Filed:

Aug 31, 2005

Appl. No.:

11/216651

Inventors:

Hernan D. Romero - Buenos Aires, AR
Jay M. Towne - Newbury NH, US
Jeff Eagen - Amherst NH, US
Karl Scheller - Bow NH, US

Assignee:

Allegro Microsystems, Inc. - Worcester MA

International Classification:

G11C 27/02

US Classification:

327 96, 327 58

Abstract:

A track-and-hold peak detector circuit, which can operate at low input signal frequencies, includes a capacitor to hold a peak voltage of the input signal and logic circuitry that reduces an effect of leakage current into or out of the capacitor, and therefore, provides protection against self-switching of an output signal of the peak detector circuit.

US Patent:

7548056, Jun 16, 2009

Filed:

Mar 3, 2008

Appl. No.:

12/041052

Inventors:

Cory Voisine - Weare NH, US
Devon Fernandez - Manchester NH, US
Karl Scheller - Bow NH, US
Ravi Vig - Bow NH, US
Kirsten Doogue - Manchester NH, US

Assignee:

Allegro Microsystems, Inc. - Worcester MA

International Classification:

G01B 7/14

US Classification:

32420712

Abstract:

Apparatus and methods for detecting passing magnetic articles using a first, True Power On State (TPOS) detector during a first time interval and transitioning to a second, running mode detector after the first time interval, when the output of the second detector is accurate. A phase comparator is responsive to the output signal of the first and second detectors and provides a control signal indicative of a change in the phase relationship between the two output signals. An output switch controlled by the phase comparator provides, as the detector output signal, the first detector output signal during the first time interval and the second detector output signal thereafter. A threshold signal associated with the TPOS detector is at a fixed level during a first portion of the first time interval and is adjusted during a second portion of the first time interval in response to an automatic gain control circuit in order to reduce the phase error associated with transitioning from the TPOS detector to the running mode detector. Also described are apparatus and methods for updating a running mode threshold signal that is a percentage of the peak-to-peak magnetic field sensor signal, so that unnecessary update events are reduced.

US Patent:

7619406, Nov 17, 2009

Filed:

Mar 3, 2008

Appl. No.:

12/041055

Inventors:

Cory Voisine - Weare NH, US
Devon Fernandez - Manchester NH, US
Karl Scheller - Bow NH, US
Ravi Vig - Bow NH, US
Kirsten Doogue - Manchester NH, US

Assignee:

Allegro Microsystems, Inc. - Worcester MA

International Classification:

G01B 7/30
G01R 33/00

US Classification:

32420725, 324225

Abstract:

Apparatus and methods for detecting passing magnetic articles using a first, True Power On State (TPOS) detector during a first time interval and transitioning to a second, running mode detector after the first time interval, when the output of the second detector is accurate. A phase comparator is responsive to the output signal of the first and second detectors and provides a control signal indicative of a change in the phase relationship between the two output signals. An output switch controlled by the phase comparator provides, as the detector output signal, the first detector output signal during the first time interval and the second detector output signal thereafter. A threshold signal associated with the TPOS detector is at a fixed level during a first portion of the first time interval and is adjusted during a second portion of the first time interval in response to an automatic gain control circuit in order to reduce the phase error associated with transitioning from the TPOS detector to the running mode detector. Also described are apparatus and methods for updating a running mode threshold signal that is a percentage of the peak-to-peak magnetic field sensor signal, so that unnecessary update events are reduced.

US Patent:

7362094, Apr 22, 2008

Filed:

Jan 17, 2006

Appl. No.:

11/333522

Inventors:

Cory Voisine - Weare NH, US
Devon Fernandez - Manchester NH, US
Karl Scheller - Bow NH, US
Ravi Vig - Bow NH, US
Kirsten Doogue - Manchester NH, US

Assignee:

Allegro Microsystems, Inc. - Worcester MA

International Classification:

G01B 7/14
G01P 3/42

US Classification:

32420713, 32420726, 324173

Abstract:

Apparatus and methods for detecting passing magnetic articles using a first, True Power On State (TPOS) detector during a first time interval and transitioning to a second, running mode detector after the first time interval, when the output of the second detector is accurate. A phase comparator is responsive to the output signal of the first and second detectors and provides a control signal indicative of a change in the phase relationship between the two output signals. An output switch controlled by the phase comparator provides, as the detector output signal, the first detector output signal during the first time interval and the second detector output signal thereafter. A threshold signal associated with the TPOS detector is at a fixed level during a first portion of the first time interval and is adjusted during a second portion of the first time interval in response to an automatic gain control circuit in order to reduce the phase error associated with transitioning from the TPOS detector to the running mode detector. Also described are apparatus and methods for updating a running mode threshold signal that is a percentage of the peak-to-peak magnetic field sensor signal, so that unnecessary update events are reduced.