Patent ID: 7486052
Filing Date: 2009-02-03
Classification: H02J,H02P

Abstract:
1. A controller for a vehicle AC generator having a first external terminal connected to a vehicle battery and supplied with generator voltage from said vehicle AC generator, a second external terminal connected to a field coil in said vehicle AC generator, and a third external terminal selectively input into a specified signal, wherein said controller comprises: an excitation switch connected to the second external terminal to control field current passed through the field coil; an excitation control circuit connected to the first external terminal to control the on/off state of the excitation switch based on at least one of the battery voltage of said vehicle battery and the generator voltage; a specified signal detecting circuit connected to the third external terminal to detect the specified signal; a voltage selector circuit that generates a voltage selector signal in response to the detection output of the specified signal detecting circuit; and a power supply circuit connected to the first external terminal to output either one of first power supply voltage or second power supply voltage higher than the first power supply voltage as internal power supply voltage, based on the voltage selector signal, said controller is constructed by using a CMOS logic circuit at least as a part thereof, the power supply circuit outputs the first power supply voltage in a first state in which the specified signal is not input to the third external terminal and the second power supply voltage in a second state in which the specified signal is input to the third external terminal, and supplies the internal power supply voltage to at least the CMOS logic circuit.