Gasoline generator excitation module replacement circuit

Circuit working principle: Generator stator winding terminal 1 (white) and terminal 2 (yellow) are
voltage detection output lines, which provide the power supply voltage of IC and IC. When
the voltage increases, the conduction of the IC2 optocoupler deepens, the width of the square wave pulse output by IC2 (NE555)
becomes narrower, and the excitation current becomes smaller, thus making the generator output voltage lower. On the contrary, it becomes
higher. Terminals 3 and 4 (blue) provide excitation power, and the actual measurement is AC110 V; terminals 7 and 8
(green/white) are the permanent magnet motor output lines of the engine, providing the excitation current for the generator to start working . Since this circuit uses the field effect transistor IRF350 as the switching output, the temperature rise is low at full load output.