| 摘要 |
PROBLEM TO BE SOLVED: To provide an encoder capable of reducing power consumption thereof while operating on power supplied from a backup battery when power from a main power source is unavailable.SOLUTION: When an encoder 1, which detects absolute rotational angular position of a rotor body, is in backup mode where power from a main power source 3 is unavailable and the encoder 1 operates on power supplied from a backup battery 4, a detector section for detecting number of turns the rotor body has rotated from a preset position of origin is turn on and off at a preset sampling period, and a signal processor section for processing an output signal from the detector section generates a square wave detection signal based on the output signal from the detector section and samples the level of the detection signal at the sampling period. The encoder 1 changes the sampling period in accordance with the sampled level of the detection signal in backup mode. |
