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
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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.
Claims22
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 first single pulse having a first pulse characteristic and a second logic data bit having a second different logic value in the data string is provided from a second single pulse having a second different pulse characteristic, wherein the second different pulse characteristic is multiple of the first pulse characteristic.
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 first single pulse having a first pulse width and a second logic data bit having a second different logic value in the data string is provided from a second single pulse having a second different pulse width.
Dependencies are inferred from the claim text.