Method and apparatus to control a low voltage fuel pump from a high voltage power source

Abstract

An apparatus and method are presented to dynamically control operation of an engine component, e.g. fuel pump assembly or oil pump assembly, so that the engine component is operable at voltages that exceeds its rated or maximum operational voltage. An engine control monitors the rail voltage provided by an engine's energy source and provides a dynamic control of the engine component to be operable at that rail voltage. In this regard, the engine component is controlled to be operable at voltages exceeding its rated or maximum operational voltage, but is also controlled to be operable at varying voltages that are above its rated maximum.

1 .- 18 . (canceled)  
   
   
       19 . An outboard motor comprising: 
 an internal combustion engine configured to provide thrust to propel a watercraft and having an alternator configured to produce an operating rail voltage within a rail voltage range when the internal combustion engine is running;    a fuel pump having a rated maximum voltage that is below the rail voltage range, wherein the fuel pump is configured to supply fuel to the internal combustion engine; and    a control unit having a control circuit to control the fuel pump to operate at a rail voltage that exceeds the rated maximum voltage.    
   
   
       20 . The outboard motor of  claim 19  further comprising a DC energy source connected to condition power from the alternator to provide DC power to the fuel pump at a voltage within the rail voltage range that exceeds the rated maximum voltage.  
   
   
       21 . The outboard motor of  claim 20  wherein the rail voltage range is from 12 volts to 60 volts.  
   
   
       22 . The outboard motor of  claim 20  wherein the DC energy source includes a switching regulator constructed to convert AC power generated by the alternator to DC power and input the DC power to the fuel pump at a voltage that exceeds 12 volts.  
   
   
       23 . The outboard motor of  claim 22  wherein the switching regulator is further configured to provide DC power to the fuel pump at a voltage of 30 volts.  
   
   
       24 . The outboard motor of  claim 19  wherein the control circuit is further configured to control the fuel pump to be operable at variable voltages.  
   
   
       25 . The outboard motor of  claim 19  further comprising a fuel pump drive circuit connected to the fuel pump and configured to control fuel pump operation based on input received from the control unit.  
   
   
       26 . The outboard motor of  claim 26  wherein the control circuit is further configured to pulse width modulate the fuel pump drive circuit.  
   
   
       27 . The outboard motor of  claim 26  wherein the control circuit is further configured to pulse width modulate the fuel pump drive circuit to maintain pump operation at approximately 3 amperes.  
   
   
       28 . The outboard motor of  claim 26  wherein the control circuit is further configured to pulse width modulate the fuel pump drive circuit at 10 kHz.  
   
   
       29 . The outboard motor of  claim 19  wherein the internal combustion engine is a two-cycle engine.  
   
   
       30 . The outboard motor of  claim 19  wherein the internal combustion engine is a rope-start engine.