| 摘要 |
PROBLEM TO BE SOLVED: To improve efficiency of a power supply system that can control the speeds of both a brush motor and a brushless motor and, at the same time, to reduce the cost of the system. SOLUTION: The power supply system (40) is provided with a brushless motor (42) and a brush motor (44), a DC-DC converter (46) which supplies electric power to the brushless DC motor (42), and another DC-DC converter (48) which supplies electric power to the brush DC motor (44). Each converter is provided with an input means (52) connected to a high-voltage bus (50), another input means (54) which receives a speed control signal (SC) indicating a desired motor speed, and an output means (56) which supplies a driving signal to the DC motor (42 or 44). Each converter is actuated in response to the speed control signal (SC) to convert actuating power into a lower-voltage variable motor driving signal. The variable motor driving signal is a variable DC voltage signal or PWM signal. A single converter design contains a single speed interface and can actuate the DC motors of both types. |
