Water level controller for the water tower as shown in the circuit. The figure, IC2 available a variety of 555 integrated circuits. Decoder integrated circuit for the infrared receiver IC3 CX20106A. IC4 available 4N25, 4N26, PC817 and other optocoupler. Infrared receiver can also buy some product components or integrated infrared receiver infrared receiver may be easy to produce and improve reliability. VD1, VD2 and VD3 use of infrared remote control transmitter and receiver diodes. J made a new selection of memory self-locking relay, relay and general appearance of the product the same, the difference is not required to maintain the current after the pull, pull and release only a certain pulse drive power is required, then the mechanical structure to maintain " locked. " The main parameters: Rated voltage 12V, trigger pulse width> 20ms rectangular driving pulse, transient power consumption <0.9W, life expectancy is 10 million times. Contact currents 3A, 30A, etc., can be selected. For the three-phase pump motor can be controlled through the relay contactor. The remaining components shown by the attention.