| 摘要 |
PROBLEM TO BE SOLVED: To achieve rotation speed to be controlled in a comparatively short time by changing it before non-cyclic operation, at the time of start, and/or as a function of a voltage of a power supply mounted on an automobile which is determined during operation. SOLUTION: A pump motor 1 is connected with a voltage Ubatt of a power supply mounted on an automobile through a changeover means 3 which can be operated. The changeover means 3 can be operated by a controller 4. The changeover means 3 is formed as an electric field effect transistor. When the change-over means 3 is closed, a current flows into the pump motor 1. When operation is shifted from all operation in a short time to cyclic operation, a first pulse/pulse halt ratio expressed by operation time and non-operation time is set as a function of a voltage of a power supply mounted on the motor vehicle. Since this first pulse/pulse halt ratio can be determined during all operation already, speedy control to desired rotation speed of the pump motor 1 or a return pump 2 can be achieved as a result. |
