Found power Supply. Will it work?

[pilotwill]

Hi all,

I am new to powering an outdoor layout. I have a 120 foot figure 8 in the yard. I have been thinking about either RC or DCC with constant power to the tracks.The other day I found in my uncles old stuff (he was starting to get into g-scale when he passed) a power supply, an MG Electronics PS24B. The box reads "Bench Power Supply Max. Output: 12vDC~24A (fully Regulated)" Would this work doe G-Scale outdoor railroads? The manufacturer's website says the unit can be used for "model trains" but that is all the info they have. What I don't know is really what is the max power you can put into the tracks before your trains start puffing the "magic" blue smoke or catch fire. LOL what I can find on the internet about powering your layout is that 10 A is good but if you can go more that is better. But is 24A too much? I 12 volts too much? Help.

So the real question is. Can I use this found power supply for my small outdoor layout? or do I still need to buy power?

thanks in advance

 

[a98087]

Yes you can use that power supply but the trains are designed for 24v so won't reach their top speed.

As a general rule lgb motors draw about 0.5 -1 amps so you have more than enough power.

Make sure you include a fuse (10 amps is more than enough) between the power supply and rails this will and prevent damage to track and power supply.


Hope this helps

Dan

 

[ntpntpntp]

As has been said above, 12 volts is a little on the low side for large scale trains which generally prefer 18 - 24 volts depending on the brand. There are a few locos out there that are rated for 12-14v, eg. the old Playmobil track powered locos and I think one or two of the Hartland Loco Works (HLW) models.

The train will only draw the current it requires, so 24 amps is more than plenty! On the other hand, that much power available could mean that the short circuit cut-out (assuming there is one?) may be set too high and you run the risk of it not tripping when it should. This can result in melted trains! It may be wise to fit a separate cut-out in your circuit, maybe 5 - 10 amps (again as Dan has suggested above) depending on how much current your largest/heaviest train draws? I believe a multiple loco lash-up with a string of coaches all lit with bulbs can get up to the 10 amp mark.

 

[GAP]

I run all of my trains but one on 10.8-12V most are LGB but I run small industrial style trains so the slow speed looks natural and they are onboard battery so I have no voltage drop problems.

If you needed more voltage you might like to consider a Dc-Dc up converter similar to this one.

http://www.banggood.com/600W-DC-DC-Boost-Converter-Step-up-Module-Mobile-Power-Supply-p-88973.html?currency=AUD&createTmp=1&utm_source=google&utm_medium=shopping&utm_content=saul&utm_campaign=Electronic-xie-au&gclid=CNepq_TIxMUCFUFwvAodb58AAg

Its specs are;
Input voltage: 10V-60V
Input Current: maximum input current 15A
Output voltage: 12V-80V continuously adjustable
Output current: maximum output current of 10A (adjustable)
Output power: effective power P = input voltage V x 10A
Conversion efficiency: up to 95% (input voltage and current; conversion efficiency of the output voltage, current impact)
Short-circuit protection: fuse

The only thing that may be an issue with this one is that the max input current is 15A so to use this one some sort of current limiting would be needed.
Something as simple as a light bulb with a known wattage in series between the power supply output and the input will work eg a 120W light globe will limit the current to 10 amps.
The brighter the lamp glows the more resistance it introduces so the less current that flows, simple effective and no real electrical knowledge other than ohms law needed

This calculator may be of some help

http://www.rapidtables.com/calc/electric/Watt_to_Amp_Calculator.htm

 

[James Day]

I must say, 24 amps sounds rather scary. A fuse or trip will be essential to protect the trains, track and controller.

I really can't imagine what anyone would want a 24 amp supply for, or visualize the cable size needed to carry that safely. I always regarded things like the much applauded 10amp LGB Jumbo as unnecessarily powerful.

I have used 5amp supplies for some years. For me 5a is enough and is safe for traction, auxiliaries and lighting. I have three separately fed tack sections on my line, as my desire was to have enough power for several large locos with a lit trains anywhere on the layout, without having too much. I have seen the damage that an unprotected high amperage supply can do to stock and track when something goes wrong.

The key requirements are that the supply is housed indoors in the dry. Cables run out to the track and the controller (if you are going to have one), although that could be inside, but the LGB 5amp rated weatherproof huts are pretty stoical.

The cables that take the feed outside (and those that take the controlled supply to the track) need to be as fat in profile as practical and ideally feed the track in several places.

The key thing to consider is really sound joining of cables AND bonding of the rails. The higher the available amperage the more important these become.

Some say that soldered wires across track joints are important, and if you want to go this far, you will never have any issues. In reality tight, freshly squeezed fish-plates with a dollop of conductive paste will do a great job for years. LGB Graphite grease is fine, but Halfords copper grease has done me proud and is much better value.

Good luck.

James

 

[pilotwill]

wow thanks for all the advice. It sounds like this is not what my uncle bought this power supply for. So maybe I use it to run lighting to the layout. I would rather blow bulbs or LED's before a blow a train.

Again thanks for the help and the links.
-Will