> WR> LED's come in all sorts of voltage ratings, with different
 > WR> current ratings too.
 >
 >Eh?  Most of what I've seen is spec'd in the 1.6 - 1.8 volt range,  with
 >the exception of the stuff that's designed with a built-in current
 >limiter,  but that's not the same thing at all.
 >
 > WR> If wired in series (N of one hooked to P of the next, and so
 > WR> on) 3 volt LED's can have four across a 12 volt circuit.
 >
 >Where do you find 3 volt LEDs?  And what's going to limit the current in
 >that setup?  Have you ever seen the voltage vs. current curve of one of
 >those parts?  It's damn near a vertical line!
The intent was to show that there are different voltage/current
combinations, and the original poster needs to pick the right one for his 
application. Generalized examples were given for series and parallel 
circuits. In a series circuit, the devices themselves will provide some 
current limiting. Increased current flow will decrease the voltage drop 
across them, causing the forward bias to decrease.  In the real world, if the 
devices are spec'd right, lead resistance combined with the voltage drops 
will limit current. Remember, the thread started with putting several LED's 
along baseboards, for inexpensive long lasting night lights in the hallways & 
elsewhere.
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