| 摘要 |
A pulse generating means is adapted to be rotated in either direction by a manual operation and to produce a plurality of trains of pulse signals the frequencies of which are varied in accordance with the speed of rotation. The pulse trains have different phase differentials which are inverted when the direction of the rotation of the pulse generating means is reversed. Either the up counting mode or the down counting mode of an up-and-down counter is selected in accordance with the output from the pulse generating means, so as to correct the contents of the counter by an addition or a subtraction. |
