| 摘要 |
PURPOSE:To maintain stable phase-lock condition at all times regardless of the change of environment or fluctuation in load, by forming the structure where the quantity of control at an expected rotating speed is automatically decided. CONSTITUTION:A microprocessor CPU introduces a feedback signal FG to send out a phase comparison signal PC, a speed control signal FV and a thresh old control signal TC. When the duplicating magnification is set at Z% by an operator, CPU works out a threshold epsilon at Z% of the magnification and sends out a threshold control signal TC to a D/A converter DA. On this account, the CPU can forecast and operate a proper threshold according to the set magni fication and control the system so that the phase-lock will not go out of place. |
