Model Railroad Layout Update Video 13- Computer Power Supply for Model Railroad

Welcome to another update video, in this video we show how we used a computer power supply to make a power supply for the layout. This is a regulated supply that will provide +5v and +12v for the C/MRI electronics and other power requirements.

[@matthardey8027]

Excellent video. Make sure you fuse all of your voltage outputs. These computer PS's are like mini-arc welders and have the potential to be fire hazards.

[@singhjobim9719]

thanks for taking the guesswork and mystery out this process. This video served as a great template and got me started on up-grading from DC to DCC . I can scrounge and find parts but I lack the basic electronic knowledge, so this really helped.

[@steven4350]

Just Awesome videos! Being new to model railroading, you explain what your doing so that I can understand it lol. Thanks for sharing...

[@ratherbeflying101]

Can't believe it's already 7 years.

[@w.rustylane5650]

Nice video. Thank you for sharing you knowledge of computer power supplies. I think that I shall use a cheapo "Chinese" 5A pw supply that powers the 3 meter LED strips. A lot cheaper than a computer pw. supply. I really don't need a 5V pwr. supply--12V is all that I need, but I need at least 3 amps.

[@paulliuzzo1320]

Very informative video. thanks, looks like you are going to have an impressive layout, looks great already.

[@corkyn34]

Nice update. Now I know what to do with my old PSUs. I'm surprised you didn't use 3.3v - the orange wires. That would be perfect for LED lighting

[@rvooyen]

Interesting about the sense. I have one for all my lighting at 12V. Just two wires. Seems ok. Robert

[@robbennett1965]

That is very possible. Some videos on the "Tube" did indicate the sense wire(s)- if present- needed to be connected. I figured better safe than sorry, so connected them in. So far it seems to be working okay!

[@ripjeffhanneman5838]

One of THE BEST videos on KZbin. Hats off to you man. You really know your shizzy! Question.. is this operation overkill for a 4x8? I just want to light buildings and lamp posts. But I don't want 30 wall warts either. Thanks buddy and very impressed!

[@aplinewalker]

Amazing,,, most of that is way beyond me im afraid ,,,, im hopeless at wiring,,, but your making awesome progress,,,, cheers and all the best for Christmas ,,,, Alan

[@esterlagendijk3044]

*you’re

[@Superseanbarry]

Love that Erie heritage in the end video! Oh, and you do great work!! :D

[@aaronandraquel]

What model # would I look for if buying an old computer power supply? There are many models out there and it's confusing.

[@w.rustylane5650]

Just one other thing . You can use a 10 ohm resistor that equals the power output in wattage to use as a dummy load. You usually get a voltage drop when the circuit is loaded.

[@pearlyhumbucker9065]

No, you dont. These are not normal PSses - these are constructed to hold the voltage till they get overloaded - then they switch off. Computers are very sensitive for voltage drops, they usually freeze instantly as a voltage drop occurs.

[@OurModelRailroad]

Very nice. Have you thought about adding a second piece of plywood to the back and putting on a bus interface to both boards so you can just side the whole board in and out without having to mess with unscrewing anything.

[@thomasmcgehrin4205]

To keep the shelf movable move the front bracket back and put the wires in front of it. Either way you may need extra wire to make the shelf movable (I forgot and ended up tearing out the connectors to what I was working on at work.)

[@dinotom1]

Nice detailed video. Since the power supply is earth grounded how did you use them for the accessories? Are the accessories not controlled via dcc accessory decoders? I thought if the accessories were also controlled via dcc that the grounds could not be common.

[@pearlyhumbucker9065]

Hi there, I would like to add some informations regarding computer power supplies: First: The power of a psu is given as the combined power - as all rails together. That does mean you cant get the complete power out of only one rail. For the examples I use two real existing psus, one built by HP, the other built by ENERMAX, the one with around 300 Watt, the other with 250 Watt - both actually found on ebay. The data table on the HP psu states the following: "Combined power on +5 Volts and +3,3 Volts rails not exceed 175 Watt max, combined power on +12 Volts and +5 Volts rails not exceed 268 Watt max." (This information is not given on the data table of the ENERMAX) Ability of current delivery reads for the HP: -12V/0,8A; +12V/19A; +5Vaux/2A; +5V/25A; +3,3V/18A. The ability of current delivery reads for the ENERMAX: -12V/0,3A; +12V/10A; -5V/0,3A; +5V/25A; +3,3V is not given. Interesting enough: Despite having not the same combined power both psu are able to delver 25 A on the +5V-rail - or, calculated, 125 Watt. On the +12V rail this psu may deliver 19A - or 228 Watt. The combined power of +12V and +5V, calculated, gives a figure of 353 Watt - and exceeds therefore the MAX figure, given by HP, of 268 Watt for the two rails combined. What does this stand for: You can NOT get the whole current on both rails at the same time. What happens, if you try? The psu will get overloaded and therefore simply switch off. Wiring: Have a lookup @google for ATX-power connections: You will surely find many pictures and schematics and explanations. You will find that the colour coding follows a simple schematic: yellow is +12V DC, red is 5 V DC, black is ground, orange is +3,3V DC. No Sense-cable. If such siort of a cable is provided it runs separtely - often there is a separate cable or two used to control the fan in the psu if the PC is equipped with this feature. But - why are there so many wires coming out of a psu that deliver the same voltage? Several wires are running in parallel, mainly to the main board: These are needed to deliver the huge currents todays PC are consuming. The other way would be to use thicker cables. Then: There are many devices to be connected to a PSU in a PC: Harddisks, floppies, front connectors, graphic cards, usb3-cards, cd-drives - depending on how many devices are existent in a PC you may need several batches of the four wires yellow-black-black-red to connect these devices. Which PSU to choose? It does not make any sense to look for the combined power of the PSU - a PSU is designed to comply to the needs of the machine it is used for. A fileserver, housing many harddisks, does not need heavy currents for the CPU, whereas a workstation for graphic production does need this power. The first PSU needs to strong on the +12V rails, the latter needs to deliver much current on the 3,3V rail. You should determine for what you want to use the PSU, which voltages you need - and what current the PSU must deliver on the rail needed.

[@MrWolfman28]

can you please tell me about the sence wires..how do you hook them in..does it matter witch wire you hook them to..black to black yellow to yellow..i don't under stand what they are used for..the power supply i have im useing just for yard LEDS..do i still have to hook the sence wires together?..

[@Holshot14]

I Just ordered two of these from ebay, do you have a wiring diagram of which voltage are whic, what needs tied together, and which ones don't need used at all? Thanks

[@GlowGamingDanish]

Normal its on the sides on the power supply

[@bigfella1952]

Good informative video..and at the right speed and technology to understand. What is your fitted "DCC Easy" control unit..would like mine fitted instead of hand held.. x Paul x The Bigfella x

[@frostgfx]

Just happened on your video while looking for ideas for an HO Back N Forth Shelf layout. Great video and explanation. Do you have one for what I desire??? Using Digitrax and their block detection system. Want to automate the running of a train for backround noise and viewing while working. Who says you can't have a MRR in 11ft.???

[@markteague8889]

Maybe a good idea to enclose that entire frame with the power supply in plexiglass or something to prevent any little fingers from reaching in with anything that conducts and shorting any of those terminals.

[@zthanhz23]

Hello! i want to know how many amps is safe to use short circuit fuse? thank you!

[@mstanco3153]

the computer supply is not giving track power as that needs a dcc source ??

[@Tnapvrvideo]

How many volts are needed for under-the-table bus lines for HO Scale track feeders? Thanks!

[@ZanesTrains1972]

Great gob at you wireing skills.

[@suelinerr]

Very nice. Thanks for sharing.

[@DonaldSimsProduction]

Well presented. Thank you.

[@robertlewis7237]

THANK YOU FOR VIDEO

[@robertsmith6050]

Hi: Like your presentation. I purchased a power supply very much like yours. Do you power you track with this unit as well, and there is 4 - 12v outputs. .5A, 12A, and 2 - 17A. How do I distinguish one from another. Thanks. Bob

[@robbennett1965]

Robert Smith Bob- Thank you. These power supplies are used for control and signal power, not for track. Track power is totally separate and is provided by the DCC system boosters. Without seeing the supply you have I can't tell you how to identify the different 12V feeds. On the one I used there were two (2) 12V feeds- one had yellow wires the other yellow with a black stripe. Usually the higher current feeds will have more wires. You could try a good old Google search on your particular supply- may be more details out there!

[@edeptula2992]

Question, how did you figure out what size fuse to use for protection?

[@peterfaulkner7564]

Hi I am new to this Hobby, so i am learning as i go along. I would be grateful of some help. Found this very interesting & helpful. I have 500v power supply which came from my computer. Thought that it was no good but works ok, so thought i would use it for my Layout which is HO Scale & U-SHAPED. My question is, can i use this for about 20 points/turnouts with GEM POINT MOTOR & RELAY ACCESSORY SWITCH & all my led lights for buildings 12v plus resistors. Power for track is by way of my ACE DCC CONTROLLER 12V-15V. OUTPUT POWER PLUG 5.5amp. Regards Peter.

[@jacobw446]

Since the turnouts are rarely on all at once.. you should be just fine with a 500W power supply, using 12vdc. The easiest way to determine this is to add up the amps of each LED. 1 amp (roughly 12 Watts at 12vdc). An LED is typically at 1.2v at 0.025A. So 12v-1.2=10.8 then 10.8/0.025=430 Ohm common resistor (or you can use 470 Ohm). Power=Voltage x amperage. So an LED at 1.2v x 0.025A=0.03A. Or 33.333 LED's per amp. 33 x 20 amps = 666 LEDs. You could easily do HUNDREDS of LED's on a 500W power supply (typically at 20Amps per output rail)!

[@steveseifer6784]

Will that one power supply power all the accessories in the system?

[@Superseanbarry]

Were you a sailor? We used a lot of "handy dandy" stuff in the USN.

[@komokaTrainMan]

What wattage of circuit breaker did you use, any recommendations? i have several old PSU i'm considering converting. right now my layout is DC as i inherited a large number of locomotives from my grandfather (handmade brass). one day i hope to convert to DCC but it will be a while before i can do that.

[@robbennett1965]

Justin- I didn't use breakers, but fuses. They are 7 amp fuses- never have had an issue in nearly 4 years of use.

[@komokaTrainMan]

@@robbennett1965 thanks, sorry I meant fuses:) good to know. Thanks!

[@ScottDowneywoundedbear]

Great way to mount the power supply. One word of advice never put one of these power supplies in a computer. They will kill it. Computers don't like voltage drop. You should never have that much of a drop for such a small load. They are ok for the railway but not great. Being a computer tech I see all the time the problems these power supplies cause even when they are working. Personally I use a much higher quality supply. I also connect a switch to the green wire so I don't have to use the power supply if not needed. Scott

[@Superseanbarry]

+Scott Downey Hi Scott. What computer PS would you recommend? I don't know much about computers and trains although I have had several of both. Kinda like Women :D I don't care much about the Gold, Silver bronze stuff. Just solid reliable stable economical PS suitable for train operation? I ain't askin for much :D

[@ScottDowneywoundedbear]

+Superseanbarry That's the thing to have a good power supply you need to buy at least a bronze PSU. There is a reason the cheap ones don't have these. They don't even make it to the minimum standard. Which in turn causes problems. They use the cheapest parts that have been known to catch on fire or the caps blow. The distortion that come from these psu's is crazy. Most of this people don't know and then wonder why they are always having problems. They produce dirty power. You can find lot's of good psu's but they are a little expensive. There are one's Rosewell, not my favorite. I only buy from Seasonic, Corsair, Antec, etc. You are safe with any supplies with the 80 plus rating. The lower end ones are not fancy but you don't want fancy. But you have to have one with the rating to be safe. I am sure in the USA these are cheaper than here in Canada but it will worth your money in the end. Less problems with lighting, signaling and point motors failing. These cheap ones don't even help with power spikes. I think I made my point so I will stop here. The layout looks great even though I haven't commented much lately. I wasn't too happy with one person on here. Keep up the great work.Scott

[@andyevans9369]

Scott Downey iI

[@j-mac-oro7049]

What 12v line did you use for your tortoises

[@scrag2841]

You could power up your trains with one of these power supplies - DCC works with both AC or DC power to the control box. You would have to create a floating ground which is the +12V is connected to the positive terminal and the -12V is connected to negative or neutral terminal. In theory this would create a 24V floating ground system. I guess some testing would be in order to see how well it would actually work.

[@kiwibjg]

Cannot understand why you are not using the 3.3 volt section to run LED lights in buildings or on control panels. Newer power supplies are rated at over 30 amps for the the 3.3 volt section which is more than enough for the several hundred LED's on my layout. That leaves the 5 and 12 volt sections to run CMR/I and control electronics and all of my Cobalt switch machines. Waste not what not. Cheers Brendon.

[@TomCro2022]

Very nice video .....

[@waldenhouse]

I only get 10.8vdc and 5.3vdc from my spare PSU with no load. Is this common? Can it be used for model railways, do you think? (UK)

[@jacobw446]

Seems low on the 12vdc side. Try hooking up at least 500mA-1A 12v rated item, and see if it still only gives you 10.8v. Check your VOM meter too and make sure that it is good. Then take a railroad switch, and hook up the an electrical momentary switch and see if it moves the switch points when you put power to it. 10.8v might just be enough.. if your only pressing ONE electrical switch at a time. A lot of variables here.

[@BALD8BIL]

great video and I see you have your lift out in can we see have you did your lift out in the next video ?

[@richthomason4306]

This works great i use you design,,,,

[@mihai2860]

Excellent video content! Sorry for chiming in, I would appreciate your opinion. Have you heard the talk about - Januke Henatalie Formula (should be on google have a look)? It is an awesome exclusive product for mastering DCC model railroads minus the hard work. Ive heard some extraordinary things about it and my best friend Jordan at very last got amazing success with it.

[@Class1aNScaleModelRailroading]

What amp fuse did you use?

[@Larrikins54]

I presume you can just pull a power supply out of an old PC desktop?

[@pikazardcollectors1123]

Hello I was wondering if you would build any of these for sale?

[@THEBENNETTRAILROAD]

Never thought about that...it is an option I suppose! But, given the current work project Rob is on it won't be until later in December that this would even be possible. If interested, send a message and we can discuss further.

[@pikazardcollectors1123]

what one cost if he was too build for sale?

[@pikazardcollectors1123]

Can you make a video showing how you actually put the wires together and which ones so you don't burn the power supply up by forgetting g a wire here or there

[@wlh227]

Something is wrong as the only video I am seeing is a video of actual trains and nothing about a power supply?? Video got mixed up???

[@THEBENNETTRAILROAD]

Bill- seemed okay when I viewed it. The PS portion is up to the 19:40 mark, then we added some other stuff.

[@joelstrain6664]

can you run a dcc command station on this?

[@THEBENNETTRAILROAD]

+Joels Train Hm, I haven't thought about that. My command station uses a dedicated power supply fed with 120v house power. This computer power supply certainly has enough capacity so I assume (but don't quote me!) that if your command station used 12V DC then it may work. May need someone smarter than me to answer.

[@luctoulouse]

if your station is plug to the rails, I will not see why.. but your station give you a power output for your rail so why bother?!?

[@gluperdade7442]

I have also run a 3V bus for LEDs

[@rpm750]

I used an old Dell power supply, it powers my LED strips which illuminates the layout. It's been on for about 10 hours before and never gets hot. The LEDS are cool to the touch as well. I measured each 8 ft strip at about 1.5 amps, times 8 strips = 12 amps total. Check out Ron Klaiss's video on LED strips....kzbin.info/www/bejne/fXi5aJx7jK59lbM Great layout too!!

[@robbennett1965]

Thank you. And good video, thanks for the tip. I did use LED strips in the workshop (under the cabinets) and a short strip for some light over the power supply itself. I was thinking of doing exactly what Ron did as I am noticing some dark areas...I really should have installed 2-3 more of the LED troffers. But seeing how he did it is very helpful and I may just try it.

[@rubber20021]

led 16v 3k Current limited.

[@rubber20021]

no boost 10-20volts I see.

[@cenlaemergencylights]

would you like to come wire my layout?

[@THEBENNETTRAILROAD]

+cenlaemergencylights LOL- it is the one aspect of the hobby I enjoy the most. Well, not really soldering feeders but the wiring, controls, electronics, and the C/MRI I fully enjoy working on. Thanks for watching!

[@cenlaemergencylights]

I am going to be watching more of your videos, to get all this dcc stuff down and wiring, i am just now finishing up on the wood working part, and now it going to be placing track and wiring the part i am going to hatr

[@joseRivas-cr8zd]

Nice Video! Sorry for the intrusion, I would love your initial thoughts. Have you heard about - Januke Henatalie Formula (probably on Google)? It is a smashing one off guide for operating a DCC model railroad minus the normal expense. Ive heard some super things about it and my mate finally got cool results with it.

[@grizzblanshan5234]

Hi

[@bobjandernal7132]

C. C. C. C. C. C