Method And Apparatus For Controlling An Electronic Circuit Node Coupled To A Single Conductor Line

Abstract

Light Emitting Diodes (LEDs) are increasingly used in illumination applications. To control multiple Light Emitting Diodes (LEDs), or any other controllable light source, this document introduces a single-wire multiple-LED power and control system. Specifically, individually controlled LED units are arranged in a series configuration that is driven by a control unit located at the head of the series. Each of the individually controlled LED units may comprise more than one LED that is also individually controllable. The head-end control unit provides both electrical power and control signals down a single wire to drive all of the LED units in the series in a manner that allows each LED unit to be controlled individually or in assigned groups.

1 . A electronic circuit node for driving an output circuit, said electronic circuit node comprising:
 a single input line, said single input line receiving a nominally constant current signal;   a single output line;   a power sub-circuit, said power sub-circuit for creating a local power supply by periodically directing said nominally constant current signal into a local capacitor, said power sub-circuit shunting said nominally constant current signal onto said single output line when not directing said nominally constant current signal into said local capacitor;   a data extraction sub-circuit, said data extraction sub-circuit for demodulating control data from said nominally constant current signal; and   at least one output circuit, said output circuit controlled using said control data demodulated from said nominally constant current signal.   
     
     
         2 . The electronic circuit node as set forth in  claim 1  wherein said output circuit comprises a light emitting diode driver circuit. 
     
     
         3 . The electronic circuit node as set forth in  claim 1  wherein said light emitting diode driver circuit uses power from said local capacitor. 
     
     
         4 . The electronic circuit node as set forth in  claim 1  wherein said data extraction sub-circuit demodulates said control data by detecting current deviations from said nominally constant direct current. 
     
     
         5 . The electronic circuit node as set forth in  claim 1  wherein said single output line serves as a local ground for said electronic circuit node. 
     
     
         6 . The electronic circuit node as set forth in  claim 1  wherein said single input line is coupled to the single output line of an upstream electronic circuit node. 
     
     
         7 . The electronic circuit node as set forth in  claim 1  wherein said electronic circuit node further comprises:
 a data parsing sub-circuit, said data parsing sub-circuit parsing said control data to decode at least one command. 
 
     
     
         8 . The electronic circuit node as set forth in  claim 7  wherein a data processing circuit responds to said command by burning a local fuse. 
     
     
         9 . The electronic circuit node as set forth in  claim 7  wherein a data processing circuit responds to said command by setting a local control register. 
     
     
         10 . The electronic circuit node as set forth in  claim 7  wherein a data processing circuit responds to said command by adjusting said output circuit. 
     
     
         11 . A method of driving an output circuit on an electronic node comprising a single input line and a single output line, said method comprising:
 receiving a nominally constant current signal on said single input line;   periodically directing said nominally constant current signal into a local capacitor to create a local power supply;   shunting said nominally constant current signal onto said single output line when not directing said nominally constant current signal into said local capacitor;   demodulating control data from said nominally constant current signal; and   driving said output circuit using said control data demodulated from said nominally constant current signal.   
     
     
         12 . The method of driving an output circuit on an electronic node as set forth in  claim 11  wherein driving said output circuit comprises driving a light emitting diode driver circuit. 
     
     
         13 . The method of driving an output circuit on an electronic node as set forth in  claim 11  wherein said light emitting diode driver circuit uses power from said local capacitor. 
     
     
         14 . The method of driving an output circuit on an electronic node as set forth in  claim 11  wherein demodulating control data comprises detecting a pattern of current deviations from said nominally constant direct current. 
     
     
         15 . The method of driving an output circuit on an electronic node as set forth in  claim 11  wherein said single output line serves as a local ground for said electronic circuit node. 
     
     
         16 . The method of driving an output circuit on an electronic node as set forth in  claim 11  wherein said single input line is coupled to an upstream single output line of an upstream electronic circuit node. 
     
     
         17 . The method of driving an output circuit on an electronic node as set forth in  claim 1  wherein said method further comprises:
 parsing said control data with a data parsing sub-circuit to decode at least one command. 
 
     
     
         18 . The method of driving an output circuit on an electronic node as set forth in  claim 17  wherein a data processing circuit responds to said command by
 burning a local fuse to store data. 
 
     
     
         19 . The method of driving an output circuit on an electronic node as set forth in  claim 17  wherein a data processing circuit responds to said command by
 setting a local control register to change the operation of said electronic node. 
 
     
     
         20 . The method of driving an output circuit on an electronic node as set forth in  claim 17  wherein a data processing circuit responds to said command by
 adjusting said output circuit.