I’m President of the local Club here in Australia with a building layout and I want to make a few throttles with walk around controllers and using old computer power supplies.
Has anyone had actual experience of doing this?
I am very attracted by the high current capacity of the power supplies
My main concern is that the filtration levels in the power supply will make the trains run “worse” because of the reliance of pulsing to help motors get started.
Because many of the motors are from Old stock from the collections of the guys, (they range from old Athearn Bluebox motors to would you believe… the First run of Bachmann locos from about 1972 to modern stuff) I am concerned that running will not be as good.
Any ideas of what to expect or how to handle it or even get rid of the filtration?
Thanks in Anticipation
Trevor
President Melton Model Railway Club (www.meltonmrc.org.au)
I’ve used them for accessory power, but never train runnign power. A few problmes I see. One, the smooth power, which you mentioned. Although a transistor throttle with a pulse generator could supply better than 50/60Hz pulses anyway. Second, somewhat low voltage. Most computer supplies run a little light on the 12V side, either just at or slightly under 12V, this is lower than the output of most traditional DC power packs so your top speeds will eb reduced (not always a bad thing). Third, computer power supplies are not isoalted fromt he mains ground, the ground passes right through (as do must switchign power supplies). The idea of one of my rails connected to the mains ground does not appeal to me. FOurth, welding machine amperage - computer power supplies produce a massive number of amps on the 12V output. Seperate fuses/breakers limiting the train driving current to reasonable levels are absolutely required unle you want to melt down locos and controllers. And common-rail wiring is probably right out, because of the mains ground issue.
Also on downstream breakers - the power supplies themselves are generally not very tolerant of shorts. So bottom line, while I thinka computer power supply makes a great source of pwoer for a village full of lighted structures and street lamps, it’s not a great idea for the track power.
I use computer power supplies for Tortoise switch machines, signals, buidling lighting, and other accessory items that can be operated on 5 or 12 Volts DC, but NEVER for track power, for the same reasons cited by Randy.
The 12 volt circuits are not near as high amperage as the 5 volt circuits. Any use would require fuses or circuit breakers for any of the voltages.
Bottom line, you don’t know what you are doing, stay away from these supplies.
At one time, no load on these supplies and the voltage would rise to a level that would explode a filter capacitor. That may not be an issue anymore with the newer supplies.
Are you kidding? Because of the mega video cards these days, power supplies put out a TON of amps at 12V. I just grabbed a random 7450W supply to check. 5V is at 22A max, the 12V is at FIFTY FOUR amps max. Fuses, and lots of them. that’s nearly 650 watts on the 12V alone. Enough to surely weld a nickle silver plated wheel to nickel silver track.
As for not messing around - no, do not open a PC power supply unless you really know what you are doing. Even witht he power cord removed, those big capacitors int here store a LOT of energy for a long time after it gets unplugged. If you want to use one, make an external connectio board (good place to put your fuses) using connectors like those on the power supply, so that you just have to plug the existing connectors into your distribution board and never have to poke around inside the power supply case.