Solar water heater water level display and water supply control circuit

Circuit working principle: The water level display is a control circuit with a four-op amp integrated block LM324 as the core . When the voltage of the inverting input terminal of the op amp block is lower than the voltage of the non-inverting input terminal
, a high level , otherwise a low level is output. . When the water in the water tank is full, probe 4,
port, C, D, and E points are all immersed in the water. The principle of water conductivity is used to make the inverting input terminal of the op amp integrated block
all at low level. A. , A2, A3 and A4 all output high level to light up
the LED , one LED4. When the water level decreases, the water level probes A, B, C, and D will be
separated from the water in sequence as the water level decreases, causing the potentials of points A, port, C, and D to become high levels in sequence
, so that A. ,Az,A3,A. When the voltage of the inverting input terminal is higher than the voltage of the non-inverting input terminal
, the LED, ~ LED 4 will be extinguished in sequence to achieve the purpose of water level display.