The present invention relates to an automatic water supply apparatus for a liquid feed using a potential difference, which supplies a feed to a feeder plate located at the bottom thereof via a lower outlet of a feed supply part of a hopper case containing the feed and in which a water supply part is coupled to the upper part of the feeding plate, separate from the hopper case, to supply pigs with liquid feed mixed with feed and water, wherein the water supply unit comprises: a water supply pipe (80) installed to receive water to be supplied to the feeder plate (30) a solenoid valve installed in a part of the water supply pipe (80) and being opened or closed so as to control the flow of water to be moved according to a voltage signal of a control unit a potential sensing pin (110) spaced apart at a certain height from the upper surface of the feeder plate (30) a circuit unit for generating an actual required measurement value through a voltage sensed by the potential sensing pin (110) and the control unit for controlling the solenoid valve through the measured value of the circuit unit, wherein the circuit unit comprises: a pin voltage input unit (121) connected to the potential sensing pin (110) and receiving a voltage a reference voltage unit (122) always having the same voltage and a voltage detection unit (123) varying in voltage in the presence of moisture in the vicinity of the potential sensing pin (110), and the control unit controls whether to open or close the solenoid valve according to the voltage measured by the voltage detection unit (123).La présente invention concerne un appareil de distribution deau automatique pour un distributeur de liquide utilisant une différence de potentiel, qui distribue une alimentation vers une plaque dalimentation située à la base de celui-ci par lintermédiaire dune sortie inférieure dune partie de distribution daliment dun boîtier de trémie contenant laliment et dans lequel une partie de distribution deau est couplée à la
