Computer Power Supply

[Anonymous]

I am searching for an article that was in MRR several years ago concerning the use of a Computer Power Supply to supply power to a Layout. Anyone know the year and monthe this article appeared ?

R/Phil Euper in South Carolina

[Anonymous]

I do not know of the article. But Computer Power Supply's Can be used. I plan on using them in mine. The one thing is they have different voltage outputs. Both 5 volt and 12 volt. If you are needing basic info on power supplies. Reply back to this post I will help where I can. Or just do a web search for Power supply wiring diagrams. You should be able to find a color chart for wire colors.

Here is a good site for basic Power supply info
http://www.computerhope.com/help/ps.htm#01

[nfmisso]

Phil;

There are no issues with using an old PC supply for your layout. The four pin plug that goes to the drives has +12V, +5V and two grounds. Use your multimeter to scope out which is which.

The 12V is great for powering trains, or switch machines. The 5V is great for lighting.

Don't pay more than this:
http://www.allelectronics.com/cgi-bin/category.cgi?category=480&type=store
http://www.allelectronics.com/matrix/DC_Wall_Transformers.html

[cacole]

I have been using computer power supplies for nearly 10 years now with no problems. The two primary considerations you need to keep in mind are wattage and polarity. Older power supplies usually produced +12V and +5V. Some of the newer supplies output +-12V +-5V, so you need a voltmeter to determine the correct polarity. Be aware, too, that some power supplies must be connected to a motherboard to work, i.e., they must sense a load in order to operate. If you intend to purchase a new power supply, make sure you get one with a schematic diagram so you know which terminals to place a jumper across to make it operational. I also use computer power supplies for the layout lighting, turnouts (stall motor), and animations. There are presently three computer power supplies being used on the Cochise & Western Model Railroad Club's HO-scale layout for crossing signals, sound effects, building lights, etc., one to power our DCC system's Atari computer, and another one used on our modular layout's DCC system.

[Anonymous]

Am looking for the wattage and ohmic value of the resistor that must be provided as a load across one of the voltages in the supply in order for the supply to turn on.

[cacole]

I just placed a wire jumper across the terminals, not a resistor.

[Anonymous]

I vaguely remember there being some info on which pins you need to bridge (on the motherboard's power supply connector) to make a modern PC power unit start up without the rest of the computer on this site www.dansdata.com

Interestingly, older PC power supplies might be a better idea. The design of the power supply changed in the 1990's from the old type (known as AT) where there was a power on/off switch on the power supply to the modern type (known as ATX) where the power supply is switched on/off by a press switch connected to the motherboard. Older power supplies wouldn't need any jumpers for this reason, and it's usually fairly simple to find an old, unwanted PC with a good power supply that you can "recycle".