| 摘要 |
PURPOSE:To effectively ignite at an igniting phase angle of a wide level by switching a motor driving circuit to a full ignition during accelerating and a pulse width of an igniting pulse by a magnitude of the phase angle, and further providing a limit at a minimum value of the phase angle. CONSTITUTION:A microcomputer 3 inputs a signal from a photomicrosensor 4, calculates a present speed of a motor 5, and calculates an igniting phase angle from a speed set value and the calculated present speed from the motor 5. If the phase angle is the set value or more during accelerating, the microcomputer 3 holds a photocoupler 61 in a full igniting state irrespective of a zero- cross signal, the set value of a timer counter 32. If the phase angle is larger than the set value, an igniting pulse to be output from the microcomputer 3 becomes a long pulse width, while if it is smaller than the set value, it becomes a short pulse width. If it is smaller than a minimum igniting phase angle, it outputs at a minimum igniting phase angle. |
