Sanyo Denki Co., Ltd.

Sayno Denki Co., Ltd.

Shigeharu Katou

Kazuhiro Makiuchi

Tooru Miyajima

Toshiaki Ayuzawa

Tomohito Yamazaki

Shoji Ito

Masato Matsuda

A batteryless absolute encoder determines the accuracy of absolute position information to be output when electric power is turned on and outputs an alarm signal in the case of abnormality. The batteryless absolute encoder includes an absolute position computing section, an absolute position storing section, and a determining section. The absolute position computing section computes the absolute position of a spindle to be detected, including the number of revolutions of the spindle, based upon detection signals output from four reluctance resolvers. The absolute position storing section stores the absolute position output from the absolute position computing section when electric power is turned off. The determining section compares an absolute position output from the absolute position computing section when electric power is turned on and the stored absolute position and outputs an alarm signal if a difference between the two absolute positions is larger than a predetermined value.

Batterless absolute encoder

A magnetic absolute encoder with enhanced resolution is provided. A first cycle determining sectionutilizes data stored in a fourth angle data storing sectionto determine in which cycle of m cycles of the fourth angle data, fifth angle data, which has been newly computed in response to rotation of a rotary shaft, occurs. A second cycle determining sectiondetermines in which cycle of n cycles of first angle data that occur in first determined cycle, the newly computed fifth angle data occurs. A third cycle determining sectiondetermines in which cycle of N1 cycles of the first angle data, the current first angle data occurs, based on the first determined cycle and second determined cycle. An absolute position determining sectiondetermines the absolute position based on third determined cycle and the digital value of the current first angle data.

Magnetic absolute encoder

Growing community of inventors

Nagano, Japan

Shigeharu Katou