| 摘要 |
PURPOSE:To display the water level, by a method wherein sensing electrodes are set at respective positions different in depth from each other, and the water level is displayed when it comes at the positions of the respective electrodes. CONSTITUTION:The electrode apparatus is formed such that a common electrode rod is mounted on an insulating plate, and other sensing electrodes 2a, 2m, 2n are mounted on a rod-like body through an insulator and are connected to terminals through wires, respectively. When the water level rises to the position of the sensing electrode 2a, a transistor Tra turns conductive to cause a light-emitting diode LEDa to emit light. When the water level comes to the position of the electrode 2m, a transistor Trm is made conductive to turn ON a light-emitting diode LEDm. On the other hand, the transistor Tra is made nonconductive, causing the light-emitting diode LEDa to turn OFF. When the water level rises to the position of the electrode 2n, a light-emitting diode LEDn emits light, and a voice generating circuit device 3 is driven to give an information through audio means. |
