| 摘要 |
PURPOSE:To prevent mulfunction of the motor and breakage of an element by starting an opplication of damping and a release of damping in a voltage application phase region in a direction of continuity to a triac changing over from OFF to ON and a phase region formed just after a gate signal reises from 0. CONSTITUTION:The signal falling at T3 as (e) is fed from a gate control circuit 9 to D type FF15, since the damping is applied by turning the triac 2 ON and turning the triac 6 ON with respect to only the current in the direction arrowed from the OFF state. The triac 6 is turned ON at T4 as (f) and not broken because no voltage is applied thereto in the direction of continuity. In the following, when the signal from terminals A-C in the gate control circuit is raised as (g) for releasing the damping, D type FF14-16 feed output high-level signals at T6 as (h), however, this signal slips off from a 0-level rise of the power source current as shown by a solid line of (a), so that the triacs 2, 6 are simultaneously turned OFF. |
