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LED / Resistor Question - This should be easy for you to answer.

I noticed that on LED wiring diagrams the resistor is on the incoming current leg.  Is there any reason why the resistor could not be on the out going current leg?

If a resistor was installed on the out going leg then multiple LED could be tied in through one resistor rather than having an individual resistor for each LED.

5 answers
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Dec 2, 2009. 4:47 AMcyberpageman says:
 You are right, it generally makes no difference which leg of the LED the resistor is on, but make sure the LED polarity is right (the longer wire is positive).  You can also have several LEDs strung together with one resistor.    

There is a good tutorial at http://www.theledlight.com/ledcircuits.html and a calculator for LED arrays which gives the wiring diagram at http://ledcalculator.net/
Jan 15, 2012. 7:58 PMmakerbuilderbaker says:
It doesn't matter which side it is on, the current and voltage will still be properly limited.
Dec 2, 2009. 11:29 AMmischka says:
It makes no different where you wire up the resistor (before or behind the LED).
Dec 2, 2009. 11:23 AMlemonie says:
Yes, you're right there, no functional reason to connect one way or another.

L
Dec 2, 2009. 7:41 AMseandogue says:
Nope. The resistor can be attached to the anode or cathode. Using the anode is mainly convention.

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