Method and apparatus for providing information from a speed and direction sensor
AssigneeAllegro MicroSystems, LLC
InventorsRavi Vig, Jay M. Towne, Glenn Forrest
Life of this patent
Estimating the term…
Abstract
A method and apparatus for providing information from a speed and direction sensor is disclosed The method and apparatus detect the presence of a ferromagnetic object as it moves past a sensor The sensor determines speed and direction information regarding the ferromagnetic object, and further provides information relating to the environment surrounding the sensor or object, such as the status of an air gap between the sensor and the moving object, and the temperature of the environment in which the sensor or object is disposed
Claims48
A method of providing information about a target having at least a first edge and a second edge, the method comprising:
- detecting at least the first and second edges of the target,
- generating a pulse in response to each of the detected first and second edges of the target, with each of the pulses having a first or second pulse width with the first pulse width corresponding to a first logic value and the second pulse width corresponding to a second different logic value and wherein a first one of the first and second pulse widths is a multiple of a second one of the first and second pulse widths, and
- forming a data word using at least two pulses wherein the data word conveys a characteristic of at least one of (a) the target, and (b) an environment in which the target is disposed
A method comprising
- providing a start data sequence;
- and
- providing a first data word having at least two pulses with each of the at least two pulses having one of two pulse widths with a first one of the pulse widths being a multiple of a second one of the pulse widths
A method of providing information from a sensors the method comprising
- detecting a target;
- and
- in response to detecting the target, generating a pulse sting having one pulse for each edge of the detected target
- generating a data string from the pulse string with the data string provided from a plurality of logic data bits wherein a first logic data bit is represented by a single pulse having a first width and a second logic data bit is represented by a single pulse having a second width with the second width being approximately twice as long as the first width
A magnetic article proximity detector for detecting a magnetic article, the magnetic article proximity detector comprising
- a magnetic field sensor for providing an output signal proportional to a magnetic field,
- a detection circuit to detect at least one of (a) a parameter of the environment in which the magnetic article is disposed, (b) a parameter of the environment in which the magnetic article proximity detector is disposed, (c) a parameter related to a relationship between the magnetic article proximity detector and the magnetic article, and (d) a parameter of the magnetic article;
- and an output control circuit coupled to receive one or more signals from said detection circuit, and in response to the one or more signals for providing a data string in accordance with a predetermined protocol in which a first logic data bit having a first logic value in the data string is provided from a single pulse having a first pulse characteristic and a second logic data bit having a second logic value in the data string is provided from a single pulse having a second pulse characteristic with the second pulse width being a multiple of the first pulse width.
Dependencies are inferred from the claim text.