Ignition system for an internal combustion engine.

摘要

An improved ignition system for an internal combustion engine comprises: (a) an ignition coil (4) having a primary winding (4a) and secondary winding (4b), one end of the primary winding being connected to a battery (1) (low DC voltage supply) via an ignition switch (2) and current limiting resistor (R1) and the other end of the primary winding being grounded via a transistorized ignition switching unit (5) which receives an ignition signal generated at an electromagnetic pick-up (7) at an ignition timing, i.e., when a pick-up rotor (6) adjacent thereto rotates through an angle determined in accordance with the number of engine cylinders; (b) a distributor (9) having a rotor electrode at a center thereof connected to one end of the secondary winding of the ignition coil via a central cable (5) and having a plurality of fixed electrodes spaced radially symmetrically around the rotor electrode; (c) a plurality of spark plugs (11) each located within a corresponding engine cylinder and connected to one of the fixed electrodes of the distributor via a high-tension cable (10) according to an ignition order for the cylinders; (d) a DC-DC converter (20) which receives a low DC voltage from the battery via the ignition switch (2) inverts the low DC voltage into a corresponding AC voltage, boosts the AC voltage into a high AC voltage, rectifies the AC voltage into a high DC voltage and stores the rectified high DC voltage within a capacitor (5) so that the charged high DC voltage within the capacitor is applied to one of the spark plugs (11) via the secondary winding (4b) of the ignition coil and distributor (9) when the spark plug starts a spark discharge by means of the transistorized switching (5) unit and ignition coil (4) to break down the electrical resistance within the gap between electrodes of the spark plug; and (e) an output voltage control means (25) which controls the output voltage of the DC-DC converter (26) so as to provide an appropriate amount of ignition energy for each spark plug according to an engine operating condition.