| 摘要 |
PURPOSE:To detect a rotating speed with satisfactory responsiveness by a simple constitution for which a commutator, etc. are not used, by using a generator which uses a field magnet as a rotor, and executing division-processing, etc. CONSTITUTION:Generated voltage being in proportion to a magnetic field and rotational frequency formed by a field magnet from armatures 2a, 2b of a generator which uses the field magnet turning synchronously with a rotating body, as a rotor is applied to one terminal of dividing circuits 17a, 17b. Detecting voltage being in proportion to a magnetic field formed by the field magnet through Hall elements 3a,3b is applied to the other terminal of these circuits 17a, 17b. Subsequently, voltage which is varied in accordance with a rotating speed is outputted through switches 20, 21 which are switched through absolute value circuits 18a, 18b and a comparator 19. By this simple constitution which fixes the armature and does not use a commutator, the rotating speed can be detected with satisfactory responsiveness. |
