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bought on ebay"50 x Grain of Wheat 3mm Clear 12V 18cm Wired Mini Bulbs" ??

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  • Member since
    July 2003
  • From: Sierra Vista, Arizona
  • 13,757 posts
Posted by cacole on Monday, February 15, 2010 8:22 PM

The NMRA DCC Electrical Standard calls for a voltage of 18 to 22 volts on the track.  Most cheaper VOMs will measure something in the range of 14.2 to 14.6 volts because they cannot react fast enough to accurately measure a high frequency square waveform. 

The straight DCC voltage on the track can and will cause a 12 Volt bulb to burn out fairly quickly.  In order to use a 12 Volt bulb in a caboose or any other rolling stock, you'll need to put resistors or diodes in the circuit to reduce the voltage.

A typical voltage rectifier diode will reduce the voltage output by 1.2 Volts each, so you would need 9 diodes to reduce 22 Volts to 12.  One resistor could accompllish the same function, but unless you know the current draw of one bulb you cannot accurately compute the resistor value.

 

  • Member since
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  • From: Elyria, OH
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Posted by BRVRR on Monday, February 15, 2010 2:15 PM

JSperan

I power my layout with a Digitrax Zephyr. The documentation says the track voltage is 12 volts, so what I say you can take with a grain of salt.

I use a lot of small bulbs like those you describe for lighting passenger cars and structures. The structure lights are powered from 12v AC/DC power packs or wall warts. Those in the passenger cars are powered with track voltage.

I recently installed interior lighting in two of my cabooses. I used metal wheel sets and fabricated my own electrical pick-up systems. One with simple brass wire and the other using the springs from Kadee couplers. There are a couple of pictures and a general description of how I did the work on my website.

 Here is a link to the proper page if you are interested:

http://www.intergate.com/~acoates149/What's%20New2.html

If your DCC system puts out 16 volts, and you want to use the bulbs you have, think about putting a small resistor in series with the bulbs. That would cut down the effective voltage to the bulb, protect them from burnout and prolong their life. I'm sure someone here can provide you with the resistor value to use to restrict the voltage to 12 volts or maybe a little less.

Here is a photo of one of my lighted cabooses. It is the one with the Kadee couple spring pick-ups:

Good luck with you project. Lighting structures gives any layout a new look. Lighted cabooses are really fun.

Remember its your railroad

Allan

  Track to the BRVRR Website:  http://www.brvrr.com/

  • Member since
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  • From: Abu Dhabi, UAE
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Posted by Scarpia on Monday, February 15, 2010 11:52 AM

Great Western Rwy fan

I should have been more precise on my question, I am running DCC with a max output of 16 volts. And I want to try to use some of the bulbs for constant lighting for instance in a caboose or maybe for exterior lanterns on the caboose.So I would have pickups on the wheel sets. Or maybe thats not possible  to even do with DCC. How many volts are constantly running thru the rails with DCC? I am new to DCC so I am still figuring it all out. I could use an old DC power pack for the structure lighting no problem.

With DCC, you need to be aware of how much you're powering off of the DCC bus. Be sure to calculate the additional draw, as you can potentially not have enough juice to run your trains.  Not saying it's going to happen, but it's a consideration.

I'm using an old DC power pack like it sounds you have, for the very same purpose.

 


I'm trying to model 1956, not live in it.

  • Member since
    July 2006
  • From: Londonderry New Hampshire
  • 518 posts
Posted by Great Western Rwy fan on Monday, February 15, 2010 10:57 AM

JSperan

 If you power them with 12 Volts or less you should be fine.  GOW bulbs can be used for interior or exterior lighting.

Here's a link to the feedback page for a recent article on layout & structure lighting that might be helpful.  It's free to download and read.

I should have been more precise on my question, I am running DCC with a max output of 16 volts. And I want to try to use some of the bulbs for constant lighting for instance in a caboose or maybe for exterior lanterns on the caboose.So I would have pickups on the wheel sets. Or maybe thats not possible  to even do with DCC. How many volts are constantly running thru the rails with DCC? I am new to DCC so I am still figuring it all out. I could use an old DC power pack for the structure lighting no problem.

  • Member since
    May 2009
  • 299 posts
Posted by JSperan on Monday, February 15, 2010 9:28 AM

 If you power them with 12 Volts or less you should be fine.  GOW bulbs can be used for interior or exterior lighting.

Here's a link to the feedback page for a recent article on layout & structure lighting that might be helpful.  It's free to download and read.

  • Member since
    July 2003
  • From: Sierra Vista, Arizona
  • 13,757 posts
Posted by cacole on Sunday, February 14, 2010 7:02 PM

All you need to do is provide power to them that is at or less than 12 Volts AC or DC.  A lower voltage of 9 or 10 Volts will result in much longer bulb life.  The only thing that can cause them to burn out like you said has happened in the past is connecting them to too much voltage.  There's no need for any rectifiers or diodes with incandescent bulbs.  LEDs, yes -- bulbs, no.

 

  • Member since
    July 2006
  • From: Londonderry New Hampshire
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Posted by Great Western Rwy fan on Sunday, February 14, 2010 5:35 PM

I HAVE HAD PROBLEMS WITH BULBS BURNING OUT AS SOON AS POWER WAS APPLIED IN THE PAST RICH,I WASN'T LOOKING FOR A SMART REMARK LIKE YOURS. . ALSO I KNOW SOMETIMES YOU NEED TO USE A BRIDGE RECTIFER,MAYBE THAT WAS FOR CONSTANT LIGHTING.I KNOW THE BASICS OF APPLY POWER WALLA!! LIGHT!!!

  • Member since
    October 2006
  • From: Western, MA
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Posted by richg1998 on Sunday, February 14, 2010 5:02 PM

Wow, this is a beaut. You light up things with them. 12 volts ac or dc. 9 volts for longer life. Keep them away from plastic. If you have any ingenuity, you can figure out how to light things with them. It is called, OJT, On The Job training. End of subject.

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
    July 2006
  • From: Londonderry New Hampshire
  • 518 posts
bought on ebay"50 x Grain of Wheat 3mm Clear 12V 18cm Wired Mini Bulbs" ??
Posted by Great Western Rwy fan on Sunday, February 14, 2010 4:43 PM

I just bought these on ebay,

50 x Grain of Wheat 3mm Clear 12V 18cm Wired Mini Bulbs

Now what do I do with them? I want to use them to light structures interior and exterior,.And for marker lights ect.

How do I wire them in?

Do I need Diodes?

Do I need to make a bridge rectifier?

What other use's are they good for?

Help please... Banged Head

Ron

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