An automatic leak-proof water inlet device for a water tank, including an inner cylinder, an outer cylinder set, a floating casing and an assist floating set; wherein the outer cylinder set is consisted of an outer cylinder, a cover, a first connecting rod, a second connecting rod, an adjusting rod, an interlocking rod, an insert, a water stopper, a first spring and a second spring; the assist floating set includes a supporting seat and a float; by the above structure, it could stop water leakage of water tank automatically and close water inlet in time, to thereby avoid the waste of water resources.

An automatic leak-proof water inlet device for a water tank, including an inner cylinder, an outer cylinder set, a floating casing and an assist floating set; wherein the outer cylinder set is consisted of an outer cylinder, a cover, a first connecting rod, a second connecting rod, an adjusting rod, an interlocking rod, an insert, a water stopper, a first spring and a second spring; the assist floating set includes a supporting seat and a float; by the above structure, it could stop water leakage of water tank automatically and close water inlet in time, to thereby avoid the waste of water resources.

An apparatus for controlling a water pump having an engine that drives an impeller, a water storage tank connected to the water pump, a first water level detector that outputs an A signal when a water level is at or higher than a first height and outputs a B signal when lower than the height, a second water level detector that outputs the A signal when the water level is at or lower than a second height and outputs the B signal when higher than the height, a connection switcher that switches connection of the first and second water level detector, and an impeller controller connected to the connection switcher and adapted to control operation of the engine that drives the impeller of the water pump based on the signals outputted from the first and second water level detectors.