Abstract: A magnetic incremental motion detection system for outputting a plurality of voltage and/or current signals in analog or digital form wherein the voltage and/or current signals are a collective representation of any incremental rotational, linear, or pivotal movement of an object. A target of the system is adjoined to an object to synchronously move with the object. A plurality of indications are adjoined to the target, and uniformly and serially disposed along an area of a surface of the target. The system further comprises one or more magnetic sensors spatially positioned from the area of the surface to define air gap areas therebetween. Each of the magnetic sensors are operable to output at least one analog signal in response to a synchronous movement of the target with the object. The outputted analog signals have the same duty cycle, and are consistently out of phase with each other by the same degree.

Abstract: A magnetic sensing device comprising a magnetic sensor and a digital circuit is disclosed. The magnetic sensor is operable to output an analog signal as an indication of any movement of an object. The digital circuit can include a dynamic reference threshold generator to output a reference signal in response to a detection of a signal feature of the analog signal and to a detection of a diametric signal feature of the analog signal, and an output format generator to output a digital signal in response to a comparison of the analog signal and the reference signal. The digital circuit can include a dynamic reference threshold generator to output a reference signal in response to a detection a first pair of quadrants of the analog signal and a detection of a second pair of quadrants of the analog signal, and an output format generator to output a digital signal in response to a comparison of the analog signal and the reference signal.

Abstract: A lock for an automobile ignition system includes a sleeve having a cylindrical inner surface. A lock cylinder is provided which is rotatably mounted within the sleeve and has a cylindrical outer surface defining a cylindrical interface with the inner surface of the sleeve. The cylinder includes a keyway adapted for receiving a key used to rotate the cylinder between an off and start position. A differential magnetic comparator having a pair of magnetically sensitive areas is mounted on the sleeve for detecting when the cylinder is rotated to the start position to generate an ignition signal. A magnet is mounted to the cylinder interface for generating a magnetic flux and for activating the comparator when the cylinder is rotated to the start position. A difference in the magnetic flux density present on the pair of magnetically sensitive areas causes the comparator to generate the ignition signal.

Abstract: A security circuit includes a Hall-effect sensor for generating an output signal in response to a sensed variation in magnetic field strength. A supply voltage source is connected to the Hall-effect sensor. A latch circuit receives the Hall-effect sensor output signal and generates a latched output signal. The latch circuit operates between a set and a reset state. Circuitry is provided for monitoring the supply voltage source and for generating an output signal applied to the latch circuit. The latch circuit generates the latched output signal in response to the Hall-effect sensor output signal and the output signal generated by the monitoring circuit when the supply voltage is at a predetermined level. The latch circuit is reset when the supply voltage is below the predetermined level.

Abstract: A circuit for detecting the occurrence of an event and for providing an output signal upon the detection of the event includes a sensor for detecting the occurrence of the event. A programmable voltage source is interconnected to the sensor for generating the output signal of a predetermined voltage value. The predetermined voltage value is generated by the programmable voltage source when the programmable voltage source is activated by the sensor. Circuitry is interconnected to the programmable voltage source for preventing identification of the preselected voltage value when the programmable voltage source is not activated by the sensor.