该电路由一片四双向模拟开关集成电路CD4066为核心构成。每个电路内部有四个独立的能控制数字或模拟信号传送的开关。当水箱无水时，由于180K电阻的作用，使四个开关的控制端为低电平，开关断开，LED 不发光。随着水位的增加, 由于水的导电特性，使得IC的13脚为高电平，S1接通，LED1点亮。当水位逐渐增加时，LED依次发光指示水位。水满时， LED4发光， 显示水满。同时T1导通， B发出报警声，提示水已满。不需要报警声时，断开开关K即可。 -The circuit consists of a four-way analog switch integrated circuit CD4066 core composition. Within each circuit to control four separate digital or analog signal transmission in the switch. When the tank water, the role of the 180K resistor, so that the four low-side switch control, switch off, LED does not light. As the water level increases, the electrical properties of water, making the IC' s 13 feet high, S1 connected to, LED1 lights up. When the water level gradually increased, LED turn light level indication. Is full of water, LED4 LED display full of water. At the same time conducting T1, B alarm will sound, indicating that the water is full. Do not need to sound the alarm when the disconnect switch K can be.