| 摘要 |
PURPOSE:To materialize various compensatory characteristics with small memory capacity and facilitate change in compensatory characteristics by optionally selecting the compensatory value of the lead angle of ignition which is predetermined according to the operating condition of an engine based on the combination of setting signals inputted into the input port of a microcomputer. CONSTITUTION:A memory means 24c stores 143 a fundamental characteristic of lead angle data as the values of lead angle at each grid point representing which is formed by equally dividing the whole characteristic range of lead angle in 12 parts on the engine speed axis and in 10 parts on the pressure axis. Engine speed Ne obtained from a crank angle signal transmitted from a wave form shaping circuit 21, and a pressure value Pb transmitted from an A/D converting circuit 23, are inputted in an operating means 24b, which operates the fundamental value of lead angle from the engine speed Ne and the pressure value Pb. The memory means 24c stores compensatory values of lead angle at nine grid points which are formed by equally dividing the whole lead angle value controlling range in three parts both on the engine speed axis and on the pressure axis. Four compensatory values correspond to respective grid points and linear interporation is effected to obtain a required value of compensatory lead angle. The final lead angle value is the sum of the fundamental lead angle value and the correcting compensatory lead angle value. |
