| 摘要 |
PURPOSE:To provide a digital servo circuit serving as well as a frequency divider suitable to frequency-divide the A phase and B phase signals of an encoder. CONSTITUTION:The A phase and B phase signals of the encoder are inputted to an angle detector 1 to phase-divide them into four angle signals of 90 degree, 180 degree, 270 degree and 360 degree based on the A phase signal. Four angle signals and the signals obtained by delaying these four signals by the delay lines 3 of the same delay time are inputted to a four-bit comparator 2. In the case of A>B of the output of the four-bit comparator 2, an H level is outputted at the time of CW, and in the case of A<B, the H level is outputted at the time of CCW. The H level output signals are subjected to pulse elimination and pulse addition, and generate a direction signal and a pulse signal. These signals are inputted to a two-way shift register in which a SIN signal and a COS signal are set beforehand, and the A phase signal and the B phase signal are frequency divided. |
