A vehicle power generation control apparatus that has a power supply circuit,
a
rotation detecting circuit, an exciting current detecting circuit, an exciting
current control circuit, a torque detecting/maximum exciting current determining
circuit and a power transistor. When a speed of rotation of a vehicle generator
is detected by the rotation detecting circuit and an exciting current flowing through
an exciting winding of the vehicle generator is detected by the exciting current
detecting circuit, the torque detecting/maximum exciting current determining circuit
calculates an upper limit value of the exciting current so that a rate of change
of a generator torque does not exceed a predetermined value, and the exciting current
control circuit controls the exciting current so that the exciting current becomes
below the limit value. This can prevent the engine revolution from becoming unstable
due to variation of load or variation of engine revolution.
