| 摘要 |
A method of measuring an incrementally subdivided path or subdivided angle of rotation digitally comprises scanning the path or angle using two pick-ups whose output signals are sinusoidal and of 90 DEG phase difference, producing two alternating voltages of 90 DEG phase difference from a clock pulse generator (1) via a predetermined step-down ratio device (2), using them to modulate the pick-up output signals in devices (4, 5) whose outputs are added (6) to form a voltage vector having the same frequency as the stepped down alternating voltages, demodulating the vector in a phase sensitive demodulator (7) with a reference signal obtained by converting the demodulated vector in a pulse generator (9) these pulses being added or subtracted from the clock pulse in dependence on the vector sign and stepped down in the predetermined ratio in device (12), and counting in a counter (10) the pulses from generator (9), either up or down in dependence on the sign. <IMAGE> |
