Contactless ignition apparatus for internal combustion engine

Claim 2

A contactless ignition apparatus for an internal combustion engine having an ignition circuit, said apparatus comprising: first and second pickup coils for detecting different ignition timing points, said first and second pickup coils being so arranged that each of said first and second pickup coils produces an output necessary for actuating said ignition circuit, said first pickup coil being so arranged as to detect the lag angle ignition timing point, said second pickup coil being so arranged as to detect the lead angle ignition timing point, and first means for introducing selectively one of the respective outputs of said first and second pickup coils to said ignition circuit thereby to control ignition timing, said first means including second means for rendering ineffective the output of said second pickup coil, in response to an external signal representing the running condition of the engine to which said apparatus is coupled, when said external signal indicates that the running condition of the engine requires ignition at the lag angle position timing point, said second means including a first switching transistor, the collector-emitter circuit of said first switching transistor being connected in parallel to the output of said second pickup coil, the base current of said first switching transistor being controlled in response to the external signal representing the running condition of the engine to which said apparatus is coupled thereby to control the on-off operation of said first switching transistor.

Claim 3

A contactless ignition apparatus according to claim 1, in which said first means includes third means for rendering ineffective the output of said first pickup coil, in response to the external signal representing the running condition of the engine to which said apparatus is coupled, when said external signal indicates that the running condition of the engine requires ignition at the lead angle ignition timing point.

Claim 4

A contactless ignition apparatus according to claim 1, in which the respective outputs of said first and second pickup coils are always equivalent to each other and said first means includes a terminal to which the external signal is applied in accordance with the running condition of the engine.

Claim 5

A contactless ignition apparatus for an internal combustion engine having an ignition circuit, said apparatus comprising: first and second pickup coils for detecting different ignition timing points, said first and second pickup coils being so arranged that each of said first and second pickup coils produces an output necessary for actuating said ignition circuit, said first pickup coil being so arranged as to detect the lag angle ignition timing point, said second pickup coil being so arranged as to detect the lead angle ignition timing point, and first means for introducing selectively one of the respective outputs of said first and second pickup coils to said ignition circuit thereby to control ignition timing, said first means including second and third means for rendering ineffective the respective outputs of said second and first pickup coils, in response to an external signal representing the running condition of the engine to which said apparatus is coupled, when said external signal indicates that the running condition of the engine requires ignition at the lag and lead ignition timing points, respectively, said second means including a first switching transistor, the collector-emitter circuit of said first switching transistor being connected in parallel to the output of said second pickup coil, said third means including a second switching transistor, the collector-emitter circuit of said second switching transistor being connected in parallel to the output of said first pickup coil, the base circuit of said second switching transistor being connected to the collector-emitter circuit of said first switching transistor.

Claim 6

A contactless ignition apparatus for an internal combustion engine having an ignition circuit, said apparatus comprising: first and second pickup coils for detecting different ignition timing points, said first and second pickup coils being so arranged that each of said first and second pickup coils produces an output necessary for actuating said ignition circuit, said first pickup coil being so arranged as to detect the lag angle ignition timing point, said second pickup coil being so arranged as to detect the lead angle ignition timing point, and first means for introducing selectively one of the respective outputs of said first and second pickup coils to said ignition circuit thereby to control ignition timing, said first means including second and third means for rendering ineffective the respective outputs of said second and first pickup coils, in response to an external signal representing the running condition of the engine to which said apparatus is coupled, when said external signal indicates that the running condition of the engine requires ignition at the lag and lead ignition timing points, respectively, said second means including a first switching transistor, the collector-emitter circuit of said first switching transistor being connected in parallel to the output of said second pickup coil, said third means including a second switching transistor, the collector-emitter circuit of said second switching transistor being connected in parallel to the output of said first pickup coil, the base circuit of said second switching transistor being connected to the collector-emitter circuit of said first switching transistor.

Claim 7

A contactless ignition apparatus according to claim 4, in which the on-off operations of said first switching transistor is controlled by applying said external signal to the base of said first switching transistor.

Claim 8

A contactless ignition apparatus according to claim 4, further comprising switching means for gounding the base circuit of said first switching transistor, said switching means being subjected to on-off operation in response to said external signal.

Claim 9

A contactless ignition apparatus according to claim 3, in which the respective outputs of said first and second pickup coils are always equivalent to each other and said first means includes a terminal to which the external signal is applied in accordance with the running condition of the engine.