| 摘要 |
PURPOSE:To detect light-load and over-load of a pump, which is driven by a direct current motor, securely to stop the pump (motor). 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 previously setting the upper limit rotating speed and the lower limit rotating speed of the pump are provided. Furthermore, a processing unit 18 for comparing the rotating speed signal from the rotating speed detecting unit 16 and the upper limit rotating speed and the lower limit rotating speed of the setting unit 17 with each other, and in the case that the rotating speed of the motor exceeds the upper limit rotating speed or the rotating speed of the motor is less than the lower limit rotating speed, for outputting the pump stop signal for stopping the pump is provided. The motor M1 is stopped through an output voltage control unit 19 and a base driving circuit unit 20. |
