| 摘要 |
PURPOSE:To provide a device for preventing light-load operation of a pump device which can detect the light-load condition of a pump such as idle operation or the like and stop the operation of the pump. CONSTITUTION:In a pump device provided with a pump and a direct current motor M1 for driving the pump, a rotating speed detecting unit 16 for detecting the rotating speed of the pump or the motor and a setting unit 17 for setting the upper limit rotating speed of the pump previously are provided. Furthermore, a processing unit 18 for comparing the detected rotating speed from the rotating speed detecting unit 16 and the upper limit rotating speed of the setting unit 17 and for outputting the stop signal for stopping the pump in the case that the rotating speed of the pump exceeds the upper limit rotating speed is provided. When an output voltage control unit 19 receives this stop signal, the control unit 19 stops the motor M1 through a base driving circuit 20. |
