PURPOSE: To start up driving of all the fuel injection valves speedily when drive periods of the fuel injection valves overlap with each other.
CONSTITUTION: Fuel injection valve coils 17a, 17b, 17c, 17d are connected serially to a battery 21 and a DC-DC converter 22. The coils 17a, 17b, 17c, 17d are also connected respectively to drive circuits 42a, 42b, 42c, 42d provided with constant current circuits 50a, 50b, 50c, 50d respectively. For example, when a current is supplied from the battery 21 and the converter 22 to drive the second fuel injection valve coil 17b in a driving peiord of the first fuel injection valve coil 17a, a set current only is supplied to the first coil 17a by the first constant current circuit 50a, while all the residual current supplied from the battery 21 and the converter 22 is supplied to the second coil 17b, thereby driving of a second fuel injection valve can be started up speedily.
KUSHIBE TAKAHIRO
MORINO SEIJI
NIPPON DENSO CO