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What happens when max output from power supply for LED and Bulb lighting is reached?

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  • Member since
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  • From: Bakersfield, CA 93308
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Posted by RR_Mel on Wednesday, March 13, 2019 8:41 PM

Thank you.
 
Actually my layout is quite small 10’ x 14’.  Susanville Station has 85 figures about a dozen railroad staff, the rest are passengers.  Twenty two 12 volt GOW bulbs powered off a 8½ volt Buck Converter.
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by HOmainline on Wednesday, March 13, 2019 8:29 PM

RR_Mel

Kerry
 
The Buck Converters are a pretty slick device for adjustable voltage needs.  They are cheap, reliable and very efficient.
 
My layout is in the garage and before I changed over to the Buck Converters I was using transistor regulators and I had to use a 4” fan to pull the heat out of my control panel from the lower current regulators.  I mounted the higher current regulators on the outside of my control panel and they poured heat into the garage.  The Buck Convertors don’t even get warm to the touch.
 
I’ve had three operating for almost three years without any problems at all.  As of today I have six converters mounted inside my now very “cool” control panel drawing a total of 13 amps from my 12 volt power supply with very little heat generated if any.
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
 

 

Mel,

Your layout must be as big as Grand Central Station.  But without all those passengers!  Wink

Kerry

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Posted by irishRR on Wednesday, March 13, 2019 5:50 PM

Thank you for clarifying. That is how I am going to re wire my layout. Separate power supply for LED and Bulb. I have dimmer switches for adjusting brightness of the LED and I will be installing the step down buck converters on my GOW bulbs. Thank you for all your insight and knowledge. I have learned much over the last few days. Cheers!

  • Member since
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  • From: Bakersfield, CA 93308
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Posted by RR_Mel on Wednesday, March 13, 2019 4:51 PM

The resistors in series takes care of any LED current issue.  As long as you don’t apply full voltage to an LED your safe.  I run separate voltages for my bulbs and LEDs.  It’s not necessary to use separate power supplies unless you want to vary the brightness on one without effecting the other.  The LED resistors will take care of the current to the LEDs.  It’s common practice to use a 12 volt buss for both incandescent and LED lighting.
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by irishRR on Wednesday, March 13, 2019 4:26 PM

Not that I don't trust you, but what is your experience with running LED and bulbs...? Sounds like you may have had something happen and learned a lesson the hard way...? I am curious. I am the originator of this topic and I am interested in all advice and experience. Trying to wire my layout and I'm moving up from simple wiring to advanced with all kinds of lighting features, animations and sensors/indicating devices. 

  • Member since
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  • From: Huron, SD
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Posted by Bayfield Transfer Railway on Wednesday, March 13, 2019 3:23 PM

Let me emphasize the above about LEDs  being current devices and bulbs being voltage devices.

Don't try to run them off the same power supply.  Just don't.  Trust us, you'll be much happier.

 

Disclaimer:  This post may contain humor, sarcasm, and/or flatulence.

Michael Mornard

Bringing the North Woods to South Dakota!

  • Member since
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  • From: Bakersfield, CA 93308
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Posted by RR_Mel on Wednesday, March 13, 2019 3:02 PM

Kerry
 
The Buck Converters are a pretty slick device for adjustable voltage needs.  They are cheap, reliable and very efficient.
 
My layout is in the garage and before I changed over to the Buck Converters I was using transistor regulators and I had to use a 4” fan to pull the heat out of my control panel from the lower current regulators.  I mounted the higher current regulators on the outside of my control panel and they poured heat into the garage.  The Buck Convertors don’t even get warm to the touch.
 
I’ve had three operating for almost three years without any problems at all.  As of today I have six converters mounted inside my now very “cool” control panel drawing a total of 13 amps from my 12 volt power supply with very little heat generated if any.
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
  • Member since
    November 2017
  • 153 posts
Posted by HOmainline on Wednesday, March 13, 2019 2:04 PM

RR_Mel

 HOmainline

Mel,

I believe you misread the question.

 
My primary use is to power Grain of Wheat bulbs, my LED signals and crossings.  All of my HO vehicles have 1mm 1½ volt micro bulbs.  My layout requires many voltages to operate the various accessories.  1½ volt bulbs, 4½ volt Miller signs, 5 volts for my Arduinos that drive many different things from lighting to automated goodies.  8½ volt GOWs for structure lighting and street lights.  9¼ volts for the GOWs driven with an Arduino, and 10 volts for miscellaneous motor driven automation.
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 

Mel,

Now, that gets to the gist of my query: applications. Big Smile 

I didn't expect anyone to guess what my supplemental power needs may be (I still don't know them all), nor was I asking about the different types of converters, what they do or a description of such.  Since I'd never heard of them before, I was simply curious as to their various uses and when (and why) they may be needed.

Kerry

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  • From: Bakersfield, CA 93308
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Posted by RR_Mel on Tuesday, March 12, 2019 3:04 PM

HOmainline

 

Mel,

I believe you misread the question.

 

 

I believe I explained what a Buck Converter is and what it does, I however have no idea what you might use one for on your layout as I have no idea what your layout needs.  They provide an adjustable DC voltage source from another DC source.
 
My primary use is to power Grain of Wheat bulbs, my LED signals and crossings.  All of my HO vehicles have 1mm 1½ volt micro bulbs.  My layout requires many voltages to operate the various accessories.  1½ volt bulbs, 4½ volt Miller signs, 5 volts for my Arduinos that drive many different things from lighting to automated goodies.  8½ volt GOWs for structure lighting and street lights.  9¼ volts for the GOWs driven with an Arduino, and 10 volts for miscellaneous motor driven automation.
 
They provide an adjustable regulated DC voltage!  I have no idea what your needs might be.   
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
  • Member since
    November 2017
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Posted by HOmainline on Tuesday, March 12, 2019 2:45 PM

RR_Mel

 

 
HOmainline
Very interesting. I had not heard of a buck converter until now. Aside from the OP's use of it as cited here, for what other applications might one need - or want - to use a buck converter on a DC layout? Mine is small (5' x 7'), so the need and capacity for LEDs, GOWs, etc. are limited.
 

 

 

There are two types of Buck Converters.  The one discussed above are down converters.  They convert from a higher DC voltage (8-32 VDC) to an adjustable voltage and current regulated DC voltage (.8-the input voltage).
 
The other Buck Converter is an up converter.  It converts the input voltage (8-32VDC) to .8 to as high as 42 VDC also regulated.
 
Both come in a variety of current ratings from below 1 amp to 30 amps.
 
All of the converters that I’ve dinked around with have excellent regulation and are very well filtered and very stable.
 
They provide a clean well regulated adjustable DC voltage that can power any thing on a layout.
 
I highly recommend them, much better than using a regulator, very efficient and almost no heat dissipation.    
 
 
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 

Mel,

I believe you misread the question.

 

Kerry

  • Member since
    January 2009
  • From: Bakersfield, CA 93308
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Posted by RR_Mel on Tuesday, March 12, 2019 2:12 PM

HOmainline
Very interesting. I had not heard of a buck converter until now. Aside from the OP's use of it as cited here, for what other applications might one need - or want - to use a buck converter on a DC layout? Mine is small (5' x 7'), so the need and capacity for LEDs, GOWs, etc. are limited.
 

There are two types of Buck Converters.  The one discussed above are down converters.  They convert from a higher DC voltage (8-32 VDC) to an adjustable voltage and current regulated DC voltage (.8-the input voltage).
 
The other Buck Converter is an up converter.  It converts the input voltage (8-32VDC) to .8 to as high as 42 VDC also regulated.
 
Both come in a variety of current ratings from below 1 amp to 30 amps.
 
All of the converters that I’ve dinked around with have excellent regulation and are very well filtered and very stable.
 
They provide a clean well regulated adjustable DC voltage that can power any thing on a layout.
 
I highly recommend them, much better than using a regulator, very efficient and almost no heat dissipation.    
 
 
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
 
  • Member since
    November 2017
  • 153 posts
Posted by HOmainline on Tuesday, March 12, 2019 11:56 AM
Very interesting. I had not heard of a buck converter until now. Aside from the OP's use of it as cited here, for what other applications might one need - or want - to use a buck converter on a DC layout? Mine is small (5' x 7'), so the need and capacity for LEDs, GOWs, etc. are limited.

Kerry

  • Member since
    January 2009
  • From: Bakersfield, CA 93308
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Posted by RR_Mel on Monday, March 11, 2019 8:59 AM

I haven’t seen a high current Buck Converter with a volt meter.  I buy cheapo digital meters and glue them to the top of the converters.
 
This is my 15 amp bench test power supply with a pair of converters glued to the top.
 
 
I used a Sharpie to put a ‘V’ on the voltage pot and a ‘A’ on the current limiter pot.  The converters come with the current pot set to 8 amps or max output.
 
The configuration above gives me 5 volts for working on my Arduinos, 8½ volts for light circuits.  There is .7 volts loss through the high current light driver chips on the controllers so I tweak the voltage to 9¼ volts so that the output is 8½ volts matching the rest of my incandescent lighting.
 
 
EDIT:
 
Here is an eBay search link for the meters I use.  If you want to measure the voltage from 0 to 12 volts you will need a three wire meter, if you don't need lower than 4½ volt a two wire meter will work.
 
 
Because I also power 1½ volt bulbs with the converters I buy this one.
 
 
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
  • Member since
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Posted by irishRR on Monday, March 11, 2019 8:27 AM

This is great information. Thank you. So I can acquire a buck converter, tune down the voltage, and run as many GOW bulbs at the reduced voltage with more electrical efficiency and a prolonged life...? Do these buck converters have a read out display, or will I need a separate voltage and amperage meter to fine tune the levels?

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Posted by RR_Mel on Sunday, March 10, 2019 5:28 PM

I went with switching power supplies to reduce heat and they are many more times efficient than standard regulated power supplies.
 
It will be a small investment but so much better in the long run to get a switching power supply and converters.  If you run your layout very much the reduced electrical costs will pay for the power supply in a couple of years.   About 30% more efficient than a regular power supply as well as very little heat.
 
8 amp Converter
 
 
Any converter with the same specs will work great.
 
This is the power supply I’m using, 12 volts at 30 amps 360 Watt
 
 
Select the size that you think you will need for bulbs on your layout.
 
No resistors just teak the voltage pot and your in business regardless how many GOWs are connected up to 8 amps with one converter.
 
I run all of my accessories of the 12 volt 30 amp power supply.
 
 
EDIT:

I just noticed that store doesn't sell the lower capacity power supplies in less than higher quantities.  The same spec on eBay will have sellers that sell just one.  Another comment about the 30 amp it has a small fan that come on with any amount of current.  I had two 15 amp power supplies from the same manufacturer and they dont have a fan at all.
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
 
 
  • Member since
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Posted by richg1998 on Sunday, March 10, 2019 5:16 PM

I and most operate LED's at about 10 ma, not 20ma. Twenty ma is the max for LED's. LED's are current devices, not voltage devices. Bulbs are voltage devices. Some do use a resistor in locos with a bulb. What kills bulb life is the surge when being turned on which is why some run them at a lower voltage. If they use an old power pack, they lock down the control on the layout.

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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Posted by RR_Mel on Sunday, March 10, 2019 5:05 PM

No, I do not use resistors on my GOW bulbs.  I control the voltage going to them by adjusting the Buck Converters.  I set the voltage to 8½ volts for longer life.  I haven had a single 12 volt bulb burnout in over 25 years operating at reduced voltage.
 
You do not want to use resistors with GOW bulbs, they generate heat.  The convertors and power supplies are switching mode and produce very little heat even at high current.
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
 
  • Member since
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Posted by irishRR on Sunday, March 10, 2019 4:51 PM

I am assuming you use resistors on the GOW bulbs...? What kind/level of resistor do you use. I have to clean up the birds nest of wires soon and was thinking about doing the resistors to prolong the life of the bulbs.... 

  • Member since
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  • From: Bakersfield, CA 93308
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Posted by RR_Mel on Sunday, March 10, 2019 4:43 PM
If it has protection it will trip the breaker at more than 5 amps, if not it will over heat and burn up if you exceed 5 amps.
 
I’m not into LED lighting on my layout for structures or street lighting, all incandescent GOWs.  I use Buck Converters to reduce the voltages from 12 volts.
 
It depends on the quantity of bulbs you will be operating.  A 12 volt 70ma bulb draws about 50ma at 8½ volts.  I operate all of my GOWs at 70% for longer life as well as they are much more realistic looking.
 
I have about 150 12 volt GOW bulbs operating at 8½ volts running off my Arduino random lighting controllers drawing up to 7.6 amps from a 8 amp Buck Converter.  I have a second Buck Converter running close to 100 GOWs drawing 5 amps that are on continuously.  The 8 Amp Buck Converters have a current limiter that is set at 8 amps from the factory.  I operate the converters from a 12 volt 30 amp switching power supply that is protected with a current limiter also.
 
Regulated switching power supplies are cheap, I think I paid about $20 free S&H for my 12 volt 30 amp power supply off eBay from a US seller.  If you overload them they just back off the voltage without damaging anything.
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
  • Member since
    September 2011
  • 182 posts
What happens when max output from power supply for LED and Bulb lighting is reached?
Posted by irishRR on Sunday, March 10, 2019 4:08 PM

Hello. I am working on lighting my new expansion. This means street lights and all of the structures. I have a mix of LED and grain of wheat bulbs. The LED draw 20 mA and the 12v bulbs draw 70mA. I know how to calculate capacity for my power supply (I am using a 15v power supply with a 5000 mA output), but i am wondering what happens if i mis-calculate and wire too many lights for the supply. Do they stop working? Does it burn out the power supply? Do the lights still work, but at a  lower light output? I am hoping not to exceed my capacity, but I an also hoping not to learn a lesson the hard way. Has anyone had this happen to them? I would love to hear your experiences. Thank you.

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