[RE-wrenches] DC power for LED lighting

[Hugh Piggott]

H Dan,

On 17 Dec 2011, at 00:02, Dan Fink wrote:

>  parallel connections are BAD with LEDs, and the string with the most voltage will eventually fail first, so best practice is regulate every string.

This statement puzzles me so I wonder if you could clarify it for me?  If you connect two strings of LEDs (or batteries) together in parallel then their voltage will be the same.  So how come you are talking about one having more voltage? 

If the answer is that it's absolutely impossible to make the connections and leads have the same resistance then this same logic applies to two strings that are connected each to its own regulated supply.  If a tiny difference in voltage matters (which I doubt) then you will have the same issues with a single string.

What am I missing?

thanks

Hugh