Thanks all I now have a definitive answer on the ground question as well as the load to regulate the PS
Bob D As long as you surface as many times as you dive you`ll be alive to read these posts.
Most computer supplies these days will run with no load, but they won't regulate properly without a load - the 12V will be way low and the 5V will be high. You can theoretically handle the modifications WITHOUT opening up the power supply by building the power switch, pilot LED, and load resistor on an external board that plugs in to power supply's plug connections. For each voltage, run multiple power busses each with its own fuse - the high current on most computer power supplies is enough to weld with. Think of the computer supply as the maisn comign in your house - 200 amps or more for most people these days. This is divided out into multiple 15 and 20 amp circuits. You wouldn;t one a single monster 200 amp circuit powering everything in your house. Likewise with powering accessories on your layout.
Do NOT remove the ground. Not in general and definitely not for a switching power supply.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
As previously mentioned DO NOT disconnect the ground. To have the power supply work correctly you will need to add a load to the power supply. The power supply will act really funky (if it even turns on) with out a load. A 10 ohm 10 Watt power resistor (available at Radio Shack) has generally been a high enough load in my experience, to make these supplies work correctly. A Note of caution those resistor get HOT! you will need to have the resistor in a place that can dissipate heat and does not touch the other wires.
These supplies by design are filtered and regulated as the electronics in computers are very sensitive to voltage levels.
Another note: These power supplies generally have some large capacitors. Allow time for these to discharge before working with the supply and ALWAYS unplug the supply when working on it.
EDIT: I forgot to mention. I generally install this Resistor on the +5V line and connect the other to ground.
Colorado Front Range Railroad: http://www.coloradofrontrangerr.com/
Don't disconnect the ground connections unless you enjoy the feeling of a 110 Volt (or higher) electrical shock when you touch the case.
This is probably a switching power supply, which will be filtered and regulated. There's a possibility that it won't even turn on unless it is under load, however.
I use computer power supplies all the time to power buidling lights, Tortoise switch motors, signals, LEDs, crossing gates, etc. around the layout; but don't try to use one for track power or to run a DCC system.
By simply typing Antec BP350 into Google, I immediately found the instruction manual for this product.
http://www.antec.com/pdf/manuals/BP350_350P_EN.pdf
My experience with PC supplies is, they re NOT regulated without a load. Just maybe, the newest are. I am speaking from experience, not opinion. The supply will maintain the voltage but has to be under some minimum load. Without any load, the voltages can increase to a level to blow a capacitor.
If you have not worked with this stuff, be careful. Some start fooling with the supply and forget to unplug the AC. They figure, turn off the switch that is on many of these supplies.
http://web2.murraystate.edu/andy.batts/ps/POWERSUPPLY.HTM
http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply
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.
BTW: To turn on the power supply, you'll want to connect pin 14 to ground.
http://pinouts.ru/Power/atxpower_pinout.shtml
This supply really is NOT acceptable for DCC use. 12 Volts is too low for most scales. You'll max out around ~10.5V at the track.
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
No don't disconnect from the house ground! That could be dangerous!
Yes they are filtered and regulated.
I was given an Antec BP350 ATX computer power supply for Xmas and noticed that the low multi voltage outputs were tied to the house AC input ground. Should I disconnect the power supply grounds from the house ground & why? I read somewhere that this needed to be done but can`t remember why.
I was also told that this was a filtered and regulated supply that I need for some of my electronic boards but the tech at customer support did not sound too sure with some of his answers. Is this a filtered & regulated supply?
Thanks