PURPOSE: To prevent an erroneous electric wirings by a method wherein the device is provided with a flip-flop circuit for distribution, set and reset alternately in accordance with the output signal of a sensor for detecting the angular position of a crank shaft, and electric cischarge is effected when the output condition of the same circuit and the position of the crank shaft are in the relation of a predetermined condition.

CONSTITUTION: Sensors 1, 2, detecting the angular positions of first and second cylinders, are provided and the output terminal of the sensor 1 is connected to the first input terminal of a gate 10 and a set terminal S of a FF9 for distribution. On the other hand, the output terminal of the sensor 2 is connected to a reset terminal R of the FF9 and the input terminal of the gate 11 and the output terminals of both sensors 1, 2 are connected to the reset terminal R of the FF13. The output terminal Q of the FF9 is connected to the first input terminal of the gate 11 and the first input terminal of the gate 16 while the output terminal Q' of the same is connected to the second input terminal of the gate 10 and the first input terminal of the gate 15 respectively. Transistors 17, 18 are put ON by the outputs of the gate 15, 16, which are inputting the output of the FF13 into the second input terminals thereof, and ignition coils 19, 20 are conducted.