Charging System: Description and Operation

GENERAL INFORMATION
The charging system is a system which charges the battery with the generator output to keep the battery charged at a constant level during varying electrical load.




Operation
Rotation of the excited field coil generates AC voltage in the stator.
This alternating current is rectified through diodes to DC voltage having a waveform shown in the illustration at left. The average output voltage fluctuates slightly with the generator load condition.

When the ignition switch is turned on, current flows and excites the field coil initially.

When the stator coil begins to generate power after the engine is started, the field coil is excited by the output current of the stator coil.

The generator output voltage rises as the field current increases and it falls as the field current decreases. When the battery voltage (generator S terminal voltage) reaches a regulated voltage of approximately 14.4 V, the field current is cut off. When the battery voltage drops below the regulated voltage, the voltage regulator regulates the output voltage to a constant level by controlling the field current.

In addition, when the field current is constant, the generator output voltage rises as the engine speed increases.

CHARGING WARNING LIGHT OPERATION

When engine is stopped
When the ignition switch is switched to the "ON" position, electricity flows from the "L" terminal of the generator to the rotor coil (field coil), and at the same time the charging warning light illuminates.

When engine is being started/has started
When the engine is started, charging voltage is applied to the "L" terminal of the generator, with the result that the charging warning light is extinguished.

In addition, because battery voltage is applied to the "S" terminal of the generator, this battery voltage is monitored at the IC voltage regulator, thus switching ON and OFF the current to the rotor coil (field coil) and thereby controlling the output voltage of the generator.

Power is supplied to each load from the "B" terminal of the generator.

NOTE: The generator relay functions as a back-up for the flow of electricity to the rotor coil (field coil) if there is a disconnection or damaged wiring of the charging warning light.