Patent ID: 8624588

Claim:
A rotation detector, comprising: a magnetic field sensor for providing an output signal proportional to a magnetic field associated with a ferromagnetic object capable of rotating, the magnetic field sensor comprising: a first Hall effect element, and a second Hall effect element disposed a distance away from the first Hall effect element; one or more detector circuits coupled to receive the output signal from the magnetic field sensor, each configured to detect a rotation of the ferromagnetic object, the one or more detector circuits configured to generate a respective one or more output signals, each output signal having respective rising and falling edges; and an output protocol circuit coupled to receive the one or more output signals from the one or more detector circuits and configured to generate an output signal indicative of a speed of rotation of the ferromagnetic object and also indicative of a direction of rotation of the ferromagnetic object, wherein the output signal generated by the output protocol circuit comprises: instances of a first pulse set when the ferromagnetic object is rotating in a first direction and instances of a second different pulse set when the ferromagnetic object is rotating in a second different direction, wherein each instance of the first pulse set consists of a first quantity of pulses having one or more pulses and each instance of the second pulse set consists of a second different quantity of pulses having one or more pulses.