Submersible or centrifugal water pumps

Abstract

The present invention consists of a water pump that includes a sensor located nearby the motor of the pump, and preferably, inside the volute of a pump or at the outside wall of the pump, to detect the absence of liquid, said sensor connected and associated with an electronic controller board that is located inside the sealed compartment of the motor, the electronic board also controls the power supply of the motor.

What is claimed is: 
     
         1 . —A water pump including a motor inside a sealed compartment, an impeller, a casing for the impeller, a volute, a sensor to detect the absence of liquid, and an electronic controlling board, wherein the sensor to detect absence of liquid is located in a place nearby the motor, selected from the group of the following places: a) inside the volute, b) inside the pump inlet, c) on the outside surface of the pump inlet, d) at the external wall of the pump. 
     
     
         2 . —The water pump of  claim 1  wherein the electronic controller board is located inside the sealed compartment of the motor and isolated form the water. 
     
     
         3 . —The water pump of  claim 2  wherein the electronic controller board is connected to the sensor to detect the absence of liquid and connected to the power supply of the motor. 
     
     
         4 . —The water pump of  claim 3  wherein the electronic controller board regulates the power supply of the motor depending on the status of the sensor to detect the absence of water. 
     
     
         5 . —The water pump of  claim 3  wherein the electronic controller board saves historical status data of the sensor to detect the absence of liquid, to produce different outputs to regulate the motor power supply 
     
     
         6 . —The water pump of  claim 3  wherein the electronic controller board includes a timer to act upon the motor power supply. 
     
     
         7 . —The water pump of  claim 1 , wherein the sensor to detect the absence of liquid consists of two conductive metal parts that, when in contact with water, close the electrical circuit with the electronic controller board.