| 摘要 |
PURPOSE:To obtain an apparatus which enables the detection of a speed signal with limited ripples along with a better response by switching and differentiating outputs of a rotary encoder. CONSTITUTION:Outputs A0 and B0 of a 2-phase type rotary encoder are inverted 2 and 3 separately. Then, the outputs A0 and B0 are added up 8 while the inverted output A0 and output B0 are added up 9 and based on respective addition outputs, a logic processing 14 is performed to obtain four kinds of outputs sequentially during one cycle. Then, respective outputs inverted and non-inverted are differentiated 4 to be applied to a switching circuit 6, with which differentiated values of the outputs are trimmed near the maximum of the minimum thereof based on the four logic outputs. These switching outputs are differentiated 5 and the harmonic components of the differentiation outputs are removed with a filter 7. As a result, a DC voltage can be detected which varies in the polarity with the direction of rotation while proportional to the rotational speed from the outputs of the encoder. |
