Water pumping and controlling device

Abstract

A water pumping device includes a reservoir for receiving water, a motor coupled to the reservoir to pump the water out of the reservoir, a resistor coupled to the motor, a comparator circuit coupled to the resistor, the resistor may be used to generate a voltage signal and to send the voltage signal to the comparator circuit, and to determine whether the motor is loaded or unloaded. A power supply circuit is coupled to the motor and coupled in series with the resistor. A control device is coupled to the comparator circuit, to switch off the power supply circuit and to turn off the motor when the motor is unloaded or do not pump water, and to maintain the driving of the motor when the motor is still loaded.

1 . A water pumping system comprising: 
 a reservoir for receiving water,    a motor coupled to said reservoir to pump the water out of said reservoir,    a resistor coupled to said motor,    a comparator circuit coupled to said resistor,    said rsistor being provided to generate a voltage signal and to send the voltage signal to said comparator circuit, to determine whether said motor is loaded or unloaded,    a power supply circuit coupled to said motor, to supply electric energy to energize said motor, said power supply circuit and said motor and said resistor being coupled together in series, and    a control device coupled to said comparator circuit, to switch off said power supply circuit in order to turn off said motor when said motor is unloaded.    
   
   
       2 . The water pumping system as claimed in  claim 1 , wherein said resistor is coupled in front of said motor.  
   
   
       3 . The water pumping system as claimed in  claim 1 , wherein said resistor is coupled behind said motor.  
   
   
       4 . The water pumping system as claimed in  claim 1 , wherein said comparator circuit includes a first amplifier coupled to said resistor to receive the voltage signal from said resistor, and a second amplifier coupled between said first amplifier and said control device.  
   
   
       5 . The water pumping system as claimed in  claim 1 , wherein said power supply circuit is provided to couple said motor to a DC power.  
   
   
       6 . The water pumping system as claimed in  claim 5 , wherein said power supply circuit includes two transistors and a second resistor coupled between said transistors.  
   
   
       7 . The water pumping system as claimed in  claim 1 , wherein said power supply circuit is provided to couple said motor to an AC power.  
   
   
       8 . The water pumping system as claimed in  claim 7 , wherein said power supply circuit includes a TRIAC coupled to the AC power.