This invention relates to a charge control microcomputer device for a vehicle, in which, in order to drive the charging generator of a vehicle or the like within an optimum, predetermined range of r.p.m., a clutch device is arranged between the generator and the engine driving the generator, the predetemined value of a voltage regulator for controlling the output voltage of the generator is externally set, system failures are detected according to data received from various points in the charge system, and the results of such fault detection are displayed.
In general, in a conventional device of this type, the output of a charging generator driven by an internal combustion engine of a vehicle or the like is controlled to a predetermined value by a voltage regulator installed together with the generator, so as to charge the battery on the vehicle. However, the conventional device suffers from a drawback in that, in the case where the predetermined value is controlled during acceleration or deceleration of the engine to thereby control the output of the generator, which is a mechanical load of the engine, it is difficult to externally control the output.
Furthermore, the conventional device is disadvantageous in that the occurrence of faults in the charge system, such as, for instance, when the charging generator generates no power or is not controlled at all, and when the first rectifier output terminal is disconnected, cannot be detected or displayed.
A conventional charging generator generally employs a driving system such that the generator is driven, with a certain speed change ratio, through a belt or the like by the internal combustion engine of the vehicle. However, such a system is disadvantageous in that the output current and efficiency of the charging generator vary with the speed of the engine, so that the output current may be insufficient in the low speed operating range of the engine, and saturated at high speed operation, thus increasing the power loss and inefficiency of the system.