Best way to find power of LED's is current draw.  LED's don't measure like regular resistive devices do some times.  Voltage/current=resistance 
 
And a slight little modification of my Fan Speed controls would enable them to be used as a 12VDC 20W+ dimmer 
		
	
		
		
		
		
			
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				Dan Pesonen 
 
 
Umm,  a tank or 5
			 
		
		
		
		
	
		
		
	
	
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