John Colley

Qyestion for Bruce, et al: I understand resistors connect to the long lead on LED's. My ignorance is shown in my question...Is there a preferred polarity direction on a resistor? In other words, does polarity matter when connecting the resistor to LED and common (blue wire) or does the resistor go to the white or yellow wire? John Colley, Sonoma, CA

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HVT Dave

No Polarity

John,

The resistor has no polarity.  It can go between the blue lead and LED or the LED and white/yellow lead.  It doesn't care, but does need to be in series with the LED.

Dave

Dave

Member of the Four Amigos

 

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Norman46

No polarity

A resistor does not care which way it is oriented. Whatever works best mechanically is the way to go, and since nearly all resistors are symmetrical, you can mount them as you see fit.
Norman Modeling L&N in HO circa 1953 We don't stop playing with trains because we grow old. We grow old because we stop playing with trains. Webmaster for http://www.locallocomodelrr.org
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Bruce Petrarca

I recommend the blue wire . . .

for only one reason - that is connected to the power supply positive voltage inside the decoder. There it connects through the bridge rectifier to the track. In the event of a short between the blue wire and track or other connections, a large amount of current can be drawn. The resistor limits the current, so the only "danger" spot is the blue wire itself.

As has been pointed out resistors are polarity insensitive.

Bruce Petrarca, Mr. DCC; MMR #574

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John Colley

Thanks

Your point is gratefully received, Bruce. John Colley, Sonoma, CA

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