Simple and convenient automatic water supply device

Probe domestic switch needle KG-300K needle head diameter is 3.0mm normally open switch needle

Photocoupler

The automatic water supply device is simple in design and convenient to use, and the circuit is as shown in the drawing.

Two holes in the water inlet pipe of the pump are used to attack the wire, and two small gasoline engine spark plugs are installed as the switch "K" for detecting water. Referring to the drawing, two wires and eight circuits can be taken out.

Working principle: water is released in the village, there is water in the water inlet pipe of the pump, “K” is connected by water, the secondary AC12V of the power transformer B goes to the “a” point of the water tank, and the other channel supplies power to the VT1 through rectification and filtering. The green LED LED1 is lit, VT1 is turned on, the relay J1 is closed, the contact J1-1 is closed, the AC contactor CJ is sucked, the water is pumped, the red LED LED2 is lit, and the J1-2 is changed from normally closed to open circuit.

When the water level rises to point b, the water level continues to rise due to J1-2 open circuit. When the water level rises to point C, point C and point a are connected by water, and the power source is rectified by VD6 through C point, C1 is filtered, and given by R4. VT2 provides bias current, VT2 is turned on. At this time, VT1 is cut off, Jl line is cut off, contact Jl-1 is disconnected, Jl-2 is closed, AC contactor CJ is powered off, and the pump stops running. As the water goes on, the water level in the tank begins to drop. When the water level drops from point C to point b, Jl-l closes and VT2 continues to conduct. When the water level drops below point b, VT2 is turned off, VT1 is turned on, and the pump starts to water again, so the action is repeated and the automatic operation is completed. Water control.

In addition to R2, R14 need to be slightly adjusted if necessary, the rest can be selected according to the data marked in the figure.