The invention provides a rotation angle sensor for an automobile
steering wheel, particularly an angle sensor for the automobile
steering wheel based on a radially magnetized thin film. The angle sensor comprises a master gear (1) driven by a master rotating shaft of the automobile
steering wheel, a
pinion (2) and a bull wheel (3) which are engaged with the master gear (1) and made of
ceramic materials, two giant magnetic resistance induction chips arranged on a circuit board (6), and a micro processor, wherein the two giant magnetic resistance induction chips face towards the surfaces of the bull wheel and the
pinion respectively, and are connected with the micro processor through serial
peripheral interfaces (SPI); and the bull wheel and the
pinion are made of the
ceramic materials, and are coated with high-
magnetism medium thin films. The bull wheel and the pinion made of the
ceramic materials have high anti-abrasion performance, high-
temperature resistance, high anti-
corrosion performance and high reliability, can be relatively thin, are easy to
mount and fix, and can be produced in a large batch; furthermore, a
magnetic thin film medium has the advantages of small volume, high
magnetic intensity,
high magnetic field directivity, simple design, high reliability and the like.