Abstract: In a controller, a voltage controller operates, in an initial excitation mode, to turn selectively on and off a switch to supply an excitation current as an initial excitation current to the field winding, and operates, in a power generation mode, to selectively increase and reduce the excitation current to be supplied to the field winding to regulate an output voltage of the power generator to a target value. A mode-shift determiner determines, while the voltage controller operates in the initial excitation mode, whether to shift an operation mode of the voltage controller from the initial excitation mode to the power generation mode based on: a measured rotation number of a rotor, a threshold rotation number of the rotor, and a preset time period, the time period being equal to or longer than an expected maximum value of cycle of pulsations of rotation of the engine.

Abstract: A device for controlling an on-vehicle power generator is provided with switching means, detecting means, voltage control means, startup control means and normal state control means. The voltage control means controls the output voltage of the power generator together with the switching means. The detecting means detects state of the power generation including a startup state where the engine is in startup condition and a normal state where normal power generation has been performed. The startup control means controls the voltage control means to start/stop of the power generation based on the frequency of the phase voltage of the power generator in the startup state. The normal state control means controls the voltage control means in the normal state such that the normal state control means controls the voltage control means to continue the power generation or stops the power generation based on the frequency of the phase voltage.

Abstract: In a controller, a voltage controller operates, in an initial excitation mode, to turn selectively on and off a switch to supply an excitation current as an initial excitation current to the field winding, and operates, in a power generation mode, to selectively increase and reduce the excitation current to be supplied to the field winding to regulate an output voltage of the power generator to a target value. A mode-shift determiner determines, while the voltage controller operates in the initial excitation mode, whether to shift an operation mode of the voltage controller from the initial excitation mode to the power generation mode based on: a measured rotation number of a rotor, a threshold rotation number of the rotor, and a preset time period, the time period being equal to or longer than an expected maximum value of cycle of pulsations of rotation of the engine.

Abstract: A device for controlling an on-vehicle power generator is provided with switching means, detecting means, voltage control means, startup control means and normal state control means. The voltage control means controls the output voltage of the power generator together with the switching means. The detecting means detects state of the power generation including a startup state where the engine is in startup condition and a normal state where normal power generation has been performed. The startup control means controls the voltage control means to start/stop of the power generation based on the frequency of the phase voltage of the power generator in the startup state. The normal state control means controls the voltage control means in the normal state such that the normal state control means controls the voltage control means to continue the power generation or stops the power generation based on the frequency of the phase voltage.