| 摘要 |
PURPOSE:To prevent an engine output from its decrease due to increase of an exhaust pressure by adding an output of a pressure detecting part, in which the exhaust pressure is detected, to a throttle sensor output to control ignition timing, in the case of a device in which the ignition timing is controlled in accordance with the output of a throttle sensor. CONSTITUTION:In an ignition timing control unit 9 for an outboard motor or the like, counting of a pulse, for instance, detected at every other rotary angle 1 from a gear counting coil 14, is started by a gear pulse counting circuit 32 with a rotary angle detecting pulse, given through a waveform shaping circuit 31 from pulser coils 121, 122 mounted to a crankshaft, serving as the reference, and when the counting of the pulse reaches a predetermined counting number, a signal of detecting a crank angle is generated to turn on SCR211, SCR212 via a signal distributing circuit 33. Here, the counting number is controlled by a counting number control circuit 34 in accordance with a throttle opening signal, detected by a throttle opening sensor 16, and a pressure signal of a pressure detecting part 36 for detecting a pressure in an exhaust chamber. |
