| 摘要 |
PURPOSE:To make it possible to detect the rotary variation generated during one rotation of a rotor within a short time, by a simple circuit configuration using a down counter. CONSTITUTION:The FG signal 101 from a rotary signal generator FG for outputting pulses in the numbers of integer-times with respect to the rotary numbers of a rotor is applied to a down counter DCT 19 through a delay circuit 20 and a value obtained by counting the reference clock 103 of a cycle one before an arbitrary FG clock interval by an up counter 27 is preset to DCT 19. By this mechanism, the change amount with an FG cycle before one is always measured by DCT 19 and gate circuits 21-24, 26 detect whether the subtraction value of DCT 19 enters a numerical range predetermined at every one cycle of the signal 101 or not while the setting of FF25 is performed and the performance of recording is indicated by the Q-output thereof. |
