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RailPro => RailPro Specific Help & Discussion => Topic started by: carrson on December 17, 2019, 10:47:08 AM

Title: LED'S and Resistors
Post by: carrson on December 17, 2019, 10:47:08 AM

I purchased some nano Led lights to install some extra effects in a couple of engines that I have hardwired the LM3S module. They are rated 2.8-3.4 volts, 15-20 MA without resistors... They came with resistors for use 12-16 volts DC.
Can I wire more than one Led (3-4) to only one resistor ?

Thanks.
Larry

Title: Re: LED'S and Resistors
Post by: Alan on December 17, 2019, 11:23:27 AM

Yes you can however it does require some math on your part. Here's an instructable https://www.instructables.com/id/Multiple-LEDs-on-a-Single-Resistor/ (https://www.instructables.com/id/Multiple-LEDs-on-a-Single-Resistor/)

Be aware you may see brightness differences between LEDs due to manufacturing tolerances that you would not otherwise see if separate resistors are used. Additionally, the whole string of LEDs will extinguish if any one LED fails (Christmas tree light syndrome).

Title: Re: LED'S and Resistors
Post by: carrson on December 17, 2019, 01:49:34 PM

Thanks for the info Alan.