[CEATEC] TDK Develops Angle Sensor with GMR Elements

Oct 6, 2008
Mayuko Uno, Nikkei Electronics
An angle sensor for motors was developed with GMR elements (right end).
An angle sensor for motors was developed with GMR elements (right end).
[Click to enlarge image]
The angle sensor incorporating GMR elements
The angle sensor incorporating GMR elements
[Click to enlarge image]

TDK Corp exhibited an angle sensor developed with GMR elements and intended for motor control of hybrid and electric vehicles.

The angle sensor features a resolution as high as 0.35 and a smaller size compared with existing angle sensors that use a coil and a magnet.

The angle sensor is installed in combination with a metallic disk, which is mounted on a motor shaft. The sensor is shaped like a circular arch and has four GMR elements inside. Each of the GMR elements is loaded with a permanent magnet on the rear side.

The metallic disk is slightly oval in shape, and the distance between the disk and the sensor changes as the shaft rotates, causing changes in the magnetic field. The GMR elements detect those changes and determine the angles.

For a smooth start of hybrid and electric vehicles, there is a need for an angle sensor that can detect the angle of a shutdown motor with the resolution of 0.5 to 0.8, according to TDK. The company intends to sell the angle sensor for use in luxury hybrid and electric vehicles. Samples of the products are currently begin shipped.