| 摘要 |
PURPOSE:To reduce size and cost of a signal detecting section by modifying the shape of a rotor rotated in synchronism to the engine such that two ignition timing points are obtained with a single pick-up. CONSTITUTION:The outer periphery of a rotor 18 which is rotated in synchronism to the engine is provided with protuberance pairs 18a and 18b, 18c and 18d, 18e and 18f and 18g and 18h, with the protuberances of each pair spaced apart by an angle corresponding to a phase angle theta. The output S obtained from a pick-up 19 is coupled to one input terminal of a comparator 20. The output A of the comparator 20 is coupled both to a mono-stable multi-vibrator 39 and a selector 40, whereby the mono-stable multi-vibrator 39 produces an output signal B for a constant period of time corresponding to a time width for an angle greater than the afore- mentioned phase angle theta. The selector 40 operates such that when a control voltage D is coupled to it with the turning-''on'' of a switch 9 according to the engine-operating condition, it produces positive differential voltages G only at instants t1 and t2. With the voltage G, a switching section 33 is triggered to obtain a high ignition voltage H. |
