| 摘要 |
PURPOSE:To prevent the re-opening of water feeding action upon removing a level sensor by a method wherein a light guiding member of U-shape type, whose both ends are being opposed to a luminous element and a receptor element respectively, is provided to detect the level of a water feeding part, stop the pump and bring a circuit into self-holding condition. CONSTITUTION:The U-shaped light guiding member 9 is provided with a luminous diode 10 and a phototransistor 11 at the both ends thereof and detects the level of water by the reflecting surfaces 9a of the curved end thereof. Thereafter, when a transistor 22 is put ON, the switching circuit 24 effects the self- holding of stopping condition of the driving of the pump 5, therefore, the re- opening of the driving of the pump 5 may be interrupted even if the level sensor is picked up from a washtub (not shown in fig.). |
