PURPOSE: To produce a sufficiently high output current, during low and high speed operation, without increasing the size of a generation set by connecting two full-wave rectifiers for rectifying respective output voltage of two generating coils of a magnet type generator in series when the speed of revolution of drive shaft is low.
CONSTITUTION: Microcomputer in a switching control means 9 is initialized upon start of engine. At this time, a switching means 7 is closed to connect first and second full-wave rectifiers 3, 4 in series thus applying output voltages from both rectifiers in series onto a battery 8. Then the speed of revolution N of a rotor is calculated, and a firing time operating subroutine is executed. The speed of revolution N is compared with a prestored specific speed of revolution N3, and is N is lower than N3 the switching means 7 is closed to connect both rectifiers in series while when N is higher than N3 the switching means 7 is opened to connect the rectifiers 3, 4 in parallel.
KIRIHARA SHOZO