Eric J Shoemaker

US Patent:

8022692, Sep 20, 2011

Filed:

Jan 19, 2009

Appl. No.:

12/355882

Inventors:

Devon Fernandez - Londonderry NH, US
William P. Taylor - Amherst NH, US
Michael Morris - Deerfield NH, US
P. Karl Scheller - Bow NH, US
Eric Shoemaker - Pembroke NH, US

Assignee:

Allegro Microsystems, Inc. - Worcester MA

International Classification:

G01B 7/14

US Classification:

3242072, 32420721, 32420726

Abstract:

A sensor responsive to movement of a detection target includes a magnetic field transducer operative to provide a magnetic field signal proportional to a magnetic field associated with the detection target, a peak detector for tracking positive and negative peaks of the magnetic field signal to generate a tracking signal, and a comparator having a first input responsive to the magnetic field signal, a second input responsive to an input signal related to the tracking signal, and an output at which is provided an output signal comprising first pulses having a first pulse width when the detection target moves in a first direction and second pulses having a second pulse width when the detection target moves in a second direction.

US Patent:

20190383885, Dec 19, 2019

Filed:

Jun 18, 2018

Appl. No.:

16/010969

Inventors:

- Manchester NH, US
Eric G. Shoemaker - Windham NH, US

Assignee:

Allegro MicroSystems, LLC - Manchester NH

International Classification:

G01R 33/00
G01R 33/07
G01R 33/09

Abstract:

A magnetic field sensor includes a plurality of magnetic field sensing elements configured to generate at least two measured magnetic field signals indicative of a magnetic field affected by an object and having a first predetermined phase difference with respect to each other and a controller responsive to the at least two measured magnetic field signals. The controller is configured to generate at least one virtual magnetic field signal having a second predetermined phase difference with respect to at least one of the measured magnetic field signals. In embodiments, the virtual magnetic field signal has the second predetermined phase difference with respect to each of the at least two measured magnetic field signals.

US Patent:

20180259594, Sep 13, 2018

Filed:

May 10, 2018

Appl. No.:

15/975942

Inventors:

- Manchester NH, US
Eric G. Shoemaker - Windham NH, US
Michael Morris - Westbrook ME, US
Dominik Weiland - Sandhausen, DE

Assignee:

Allegro MicroSystems, LLC - Manchester NH

International Classification:

G01R 33/00
G01D 5/244
G01R 1/44
G01D 3/036
G01R 33/02

Abstract:

A magnetic field sensor includes one or more magnetic field sensing elements configured to generate a magnetic field signal responsive to a magnetic field and a detector coupled to receive an interpolated threshold and a signal representative of the magnetic field signal, wherein the detector is configured to compare the interpolated threshold with the signal representative of the magnetic field signal to generate a detector output signal. A memory is configured to store a first threshold value indicative of a threshold value at a first temperature and a second threshold value indicative of a threshold value at a second temperature lower than the first temperature and a threshold module coupled to the memory and configured to generate the interpolated threshold based on the stored first and second threshold values.

US Patent:

20170356760, Dec 14, 2017

Filed:

Jun 8, 2016

Appl. No.:

15/176655

Inventors:

- Worcester MA, US
Eric G. Shoemaker - Windham NH, US
Jeffrey Eagen - Manchester NH, US

Assignee:

Allegro MicroSystems, LLC - Worcester MA

International Classification:

G01D 5/14
G01D 5/16

Abstract:

Magnetic field sensors can sense speed of movement and direction of movement of a ferromagnetic object. Particular arrangements of magnetic field sensing elements within the magnetic field sensor can automatically cancel offset variations in the magnetic field sensing elements.

US Patent:

20170191852, Jul 6, 2017

Filed:

Mar 23, 2017

Appl. No.:

15/466894

Inventors:

- Worcester MA, US
Peter Cisar - Lenzkirch, DE
Eric Shoemaker - Windham NH, US

Assignee:

Allegro MicroSystems, LLC - Worcester MA

International Classification:

G01D 5/14
G01D 18/00

Abstract:

A magnetic field sensor includes a true power on state (TPOS) detector for which a measured threshold value is stored prior to power down and recalled upon power up. A corresponding method is associated with the magnetic field sensor.

US Patent:

20140145711, May 29, 2014

Filed:

Nov 26, 2012

Appl. No.:

13/685287

Inventors:

Eric Burdette - Newmarket NH, US
James M. Bailey - Concord NH, US
Daniel S. Dwyer - Auburn NH, US
Jeff Eagen - Manchester NH, US
Glenn A. Forrest - Bow NH, US
Christine Graham - Bow NH, US
Eric Shoemaker - Pembroke NH, US
P. Karl Scheller - Bow NH, US

International Classification:

G01B 7/14

US Classification:

32420711

Abstract:

A circuit to detect a movement of an object includes a magnetic field sensing element for generating a magnetic field signal proportional to a magnetic field associated with the object and a motion detector to generate a motion signal indicative of the movement of the object. The motion detector includes a peak identifying circuit to provide a peak signal and a peak sample selection module that selects a sample associated with one or more prior cycles of a magnetic field signal to generate a selected peak signal. The motion detector further includes a threshold generator to generate a threshold signal as a function of the selected peak signal and a comparator to compare the threshold signal with the magnetic field signal to generate the motion signal. Peak samples from prior magnetic field signal cycles may be averaged for use to establish the threshold signal. A method associated with the circuit is also described.