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Lights in Building Question

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  • Member since
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Lights in Building Question
Posted by donhalshanks on Tuesday, October 7, 2008 2:14 PM

I want to light the inside of the Walthers two stall Engine House I'm building.  I want to use two LED lights wired in parallel.  Can I use one resitor for both LED's, or do I need to have a resitor for each one?  It will be powered off fixed 12 volt DC terminals of an old transformer.

The building is 12" long..... do you think two LEDs will be adequate lighting?

Thanks for the help..... Hal 

 

  • Member since
    January 2002
  • From: ERIE PA.
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Posted by GAPPLEG on Tuesday, October 7, 2008 2:40 PM

The LED's can be wired up in parallel as stated , one resistor can handle them, check value for current. LED's tend to put out a focused light so it's kinda like spotlights inside a building instead of general lighting , there are LED's available that deflect the light around, this can also be accomplished by filing the leds nose down so the light gets thrown around more. I would suggest the yellow glow LED's for this rather than bright whites.

  • Member since
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  • From: Ontario Canada
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Posted by Mark R. on Tuesday, October 7, 2008 4:53 PM

Lightly sand the surface of the LED - it will help diffuse and spread the light more instead of a focused beam. Two may or may not be enough .... depends on the effect you're after. I have a modern style engine house three tracks wide and two engines deep .... it took twenty golden LEDs to get the effect I was after. There is five ceiling beams with each having four LEDs mounted on each.

Mark.

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

  • Member since
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Posted by rrinker on Tuesday, October 7, 2008 5:04 PM

 Wiring multiple LEDs in parallel is NOT a good idea. LEDs can vary in power requirements, even if they are all the same part number from the same manufacturer. What happens then is the one with the lowest power requirement (think 'electricity takes the path of least resistance') is bright and the others are dim.

 BEST is to use individual resistors with each LED and then wire those in parallel. However you CAN wire the LEDs in series and use a single resistor. The series wiring works so long as the power supply voltage is at least slightly higher than the sum total of the voltage drops of the LEDs, and you can mix and match LEDs, they don;t have to be all identical. For example, if you have two LEDs that are 2.1v and one that is 1.8v, as long as your power supply is slightly over 6 volts it will work.

 Here is a good link on LED resistors, series, and parallel wiring: http://wolfstone.halloweenhost.com/Lighting/litlpo_PoweringLEDs.html

 

                --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
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  • From: Western, MA
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Posted by richg1998 on Wednesday, October 8, 2008 12:33 PM

Inverted cone LEDs are good for lighting inside buildings. I use a few. Here is what our club uses outside of the Roundhouse. The bulbs are Miniatronics.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

  • Member since
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  • From: US
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Posted by donhalshanks on Wednesday, October 8, 2008 1:22 PM

Thanks guys!  I really appreciate your help.

Hal

  • Member since
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  • From: Western, MA
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Posted by richg1998 on Wednesday, October 8, 2008 1:39 PM

In case you have not seen the inverted cone LED, here is a photo. Nice 360 degree illumination. Careful placement and you can see the light but not the LED. I get mine off of ebay which includes a resistor for each LED to be used with 12 vols DC. Go to ebay and search for inverted cone LED. If you are not into electrical, one resistor for each LED is the best way to go. Those people who say it is easy to put LEDs in series or parallel are familiar with electronics so it is Easy for them.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

  • Member since
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  • From: Sierra Vista, Arizona
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Posted by cacole on Wednesday, October 8, 2008 7:58 PM

The best and most reliable source of inverted cone LEDs is http://www.moreleds.com 

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