| 摘要 |
PURPOSE:To suppress the generation of noises and vibrations as well as to achieve longer life of components and prevent from drift of their setting points by slowing rise-up and falling-down of a magnet drive current. CONSTITUTION:With input of a magnet drive signal DV, a voltage at point A increases up to the level determined by a voltage division ratio of resistors R2 and R3. Thereby, a reference voltage of comparator 16 increases gradually according to the time constant R1.C1. At the same time, the output of comparator 16 activates a magnet drive circuit 15, so a current I is supplied from the driving voltage source VD to a magnet coil L. A voltge at point B increases and is supplied to the comparator 16 to compare with a reference voltage, so the current I flowing through magnet coil L increases gradually. After an object to be activated has been operated, a holding signal HD is inputted. With disappearance of magnet drive signal DV and holding signal HD, the current flowing through magnet coil L decreases gradually. |
