| 摘要 |
<p>An internal-combustion engine includes a flywheel driven alternator connected to charge an ignition system capacitor which is discharged to the several spark plugs by individually controlled rectifiers. A pulse generator coupled to the flywheel includes as many triggering coils as there are cylinders and a permanent magnet unit for generating alternate positive and negative polarity pulses in each of the triggering coils. A steering diode network connects one end of each triggering coil to a related controlled rectifier for an associated cylinder and the opposite end of each coil to the controlled rectifier for a different cylinder. At low speeds the first pulses are connected to trigger the controlled rectifiers in proper sequence with the opposite polarity pulses blocked by an auxiliary controlled rectifier. At higher speeds, the auxiliary controlled rectifier conducts and allows the opposite polarity pulses to trigger the controlled rectifiers and establish an automatic spark timing advance. An actuating circuit in the form of a level-detecting circuit or electronic tachometer network actuates the auxiliary controlled rectifier and holds it conductive at all speeds above a selected level. The actuating circuit and auxiliary controlled rectifier circuit are constructed to minimize hysteresis effects and establish the automatic spark advance at a selected speed.</p> |
