If the source voltage is the same as LED voltage, is a resistor necessary?

PaulEE

Joined Dec 23, 2011
474
I did quickly glance at the previous replies and thought I'd add the built-in resistor/almost on comment as an aside...

Best-
Paul
 

Bernard

Joined Aug 7, 2008
5,784
Remember all of the flashlights that used 3 AAA or 3AA's & a bright white LED with no resistor; a few had a switch to bypass a low value resistor as batteries aged. I still have some, never lost a LED. LED's were mostly not pre selected for Vf. I converted several cheap 3-AA pen cell lights to bright white LED's with 3 N cells & spacer- no resistor. Sold for $ 13.; now 9 LED's for free at Harbor Frt.
 
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