That's kind of interesting, since there's a note on the Digitrax site about some PS14's having more than 2 wires, nothing about ones having coax.
However, if you pull it back like the illustration and attach it to a terminal strip, it should be fine. The braid SHOULD be the negative side, test with a meter to be sure.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Well, the best way would probably have been an in-line socket to fit the plug, with pigtail leads to attach to the terminal strip.
But since you're past that point, what you need to do is strip off maybe a couple inches of the outer insulation, leaving the braided shield in place. Then just past where the insulation no longer covers the braid, gently work the braid open so you can ease the still-insulated center conductor out.
After you work that insulated center conductor out, gently twist the braid to compress it into a sort of stranded wire conductor, and insulate it with a piece of heat-shrink tubing. A short length of larger-diameter heat-shrink tubing over the "joint" where the individual conductors and original outer insulation join would probably also be a good idea, to act as a strain relief.
Keep in mind that this is a "kludge" solution, and that the coax wasn't designed to be used in this manner. For that reason, it will be very fragile, especially where you disturbed the braid to work out the center conductor. So it will need to be handled/fastened/etc with care.
Unless of course someone chimes in with a better idea, because my solution as outlined above is far from ideal.
EDIT, Shoot, I was a minute too slow! Graphitehemi posted exactly what I was trying to describe, and his picture is worth a thousand words.
Found a pic showing what I'm talking about HERE
If it's woven around like a sleeve, strip the outer insulation from the cable back about 2". You should be able to loosen enough of the wire to cut a slit on one side of the sleeve. Slide it off to one side and twist it up like a normal wire. You could insulate this new 'wire' with heatshrink tubing if you are worried, but it is more then likely the common (ground) side and shouldn't cause any issue. Trim everything to a manageable length, strip the center (positive) wire and attach them to your strip (crimp on terminals, solder, screws, etc....)
Stevert,
So, that being said. How do you "fix" the outer wire so that it can be used to attach to the negative strip?
Craig North Carolina
While it is a nice box, it's kind of a waste to throw out the innards as they also make very nice power supplies since 12V is a common need, and the 5V side can power any electronics you might use.
The ones the LION opens have been out of service for months if not years. He was not doing anything to the innards, they went in to the scrap box and I was left with a nice project box with AC input.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
PC power supplies are great, but they don;t regulat very well under light or no load. Using one for say a dozen Tortoises won;t even be a noticeable load. You can do things liek install a high wattage sandbar resistor to create a load. Newer power supplies cna be used as well, the "turn on" wire is in the 20/22 pin connector, just needs to be grounded to turn power on.
If you don't knwo what you're doign, do NOT open up a PC power supply and attempt to modify it. There are large capacitors inside that hold quite a jolt for long after the power cord is disconnected. The various Molex connectors used on power supplies are very easy to find though, so you cna build up any sort of control and distribution circuit, even the load resistor, by simply aquiring mating connectors and connecting to the power supply. Do not under any circumstances wire the 12 volt output directly around the layout, at that current you are definitely in the welding arena, and things can easily get hot enough to start a fire. Use fuses or circuit breakers to break the high power into multiple low power circuits. This also helps because PC power supplies are not very tolerant of shorts on the outputs, the fuses will protect the power supply as well as your layout.
The LION built his power supplies BEFORE PCs were invented. Yes, I have thought of using them, but only used the case to mount my own works in. I should have used one to power my trains, but instead I went out and bought a variable voltage 15 amp regulated supply. I run my trains on about 10.5 volts, I have no throttles controls or reversing switches, but that is a different story.
I too had a problem with shorts. 15 Amps is enough to set some of my control resistors on fire should there be a short. Sure, the power supply is protected against shorts but it will still put out 15 amps before it trips. If you go to the big supplies like this, put your own fuses in the line, two or three amps should be sufficient. Or put an automobile tail lamp in series with the load. The load will be too small to light the bulb under normal conditions, but if there is a short the bulb will light up and draw off the current.
For lighting and aux... go ahead and use a computer supply, just be sure to keep a load on it somewhere, a bulb or two that are not turned off while the supply is on, then you will have good clean output for your needs.
Hi
Something you might think about ... PC power supplies - AT style ( has on/off switch )
30A at 5VDC
12A at 12VDC
There are mod'n instructions - google it.
I use these pretty much exclusive for just about anything as it has an existing case, and I don't have to fuss with line voltage AND there is already a cooling fan! Do note that 30A can put a BIG divot in just about anything if you happen to short the output leads to something. Supply shuts down, but you still have the 'smoke and fire', so be careful if you decide to go this route. Note that ATX supplies can also be mod'd, there are only a few additional steps. And for test purposes, you need to put a load on the 5V side to keep the switcher running. If I remember correctly, you need about 200mA for a load - I just plug in an old hard drive which is overkill! Once you have it in/on your layout, the 'keeper' load can go away.
Todd Hackett
Libby, Montana 59923
I take only pictures then leave footprints on railroad property that I know is not mine, although I treat it as such...
The LION built his own from open frame transformers. He uses two of them, but one would work just as well, if you are comfortable soldering on the 110 volt side. I bought two identical 5Amp transformers and connected the primary together to a common 110volt wire with a grounded plug. There are identical 5Amp full-wave rectifiers on the secondary. From the rectifiers the (+) wire of 1 and the (-) wire of 2 are connected to ground, and this ground becomes the common wire both in the console and around the layout. The (-) wire of 1 provides -12v dc to common; the (+) wire of 2 provides + 12v ds to common; and across both wires is 24 volts, which the LION needs for some of his relays, for he got a very good deal on 4PDT 24v relays many years ago.
So the (+) 12 v dc line (hereafter called the RED bus); and the (-) 12 v dc line (called the GREEN bus) are also distributed through the console and around the layout.
SPDT switches are provided on the console for each switch machine, they select between the GREEN bus (normal position) or the RED bus (the reverse position). For console LEDs, they run of the stinger (common terminal) of the switch. If you use pairs of LEDs reverse one of them, so that Green will display in the normal position and red will display in the reverse position. Or just use a Bi-color led to ground oriented to be colored correctly.
Thus each Tortoise is controlled by a single conductor. Again wayside LED signals can be run off of this same single wire. Track power can be routed by the Tortoise, or a relay (either a 24 volt relay or a 12 volt relay guarded by a rectifier) can work additional track or signal logic out on the wayside.
If you do not know what I just said, you probably do not want to try it, but you can message me, and I'll try to draw you a diagram.
Radio Shack still has all manner of wall-wart power supplies that are suitable if you are using Tortoise machines. Or you cna find an equal number at far lower prices on eBay, not as auctions but at fixed price. Most made in CHina (but then the RS ones are too), but in many cases say ship from the USA so you get them quick. I have a 14V one I ordered for powering accessories and I had it in a couple of days. For Tortoises with LEDs in series a 12V suply would be good. Not much current is needed, a 1 amp supply is good for at least 50 Tortoises. Many of these power supplies are replacements for computer accessories that use external power bricks - the 14V one I have in fact is for a brand of LCD monitors. Sometimes a pinout of the conenctor is printed on the supply, if not, just cut off the plug and use your meter to determine which is + and which is -.
Aikidomaster I am wondering what folks use to power their control panels. I use Tortoise switch machines for turnouts. My control panels have green and red LED's from Radio Shack. I have powered the first panel with a 12 volt power pack, that my father-in-law bought 10 years ago. I am not finding similar products. So, what is everyone else doing??
I am wondering what folks use to power their control panels. I use Tortoise switch machines for turnouts. My control panels have green and red LED's from Radio Shack. I have powered the first panel with a 12 volt power pack, that my father-in-law bought 10 years ago. I am not finding similar products.
So, what is everyone else doing??
I wire my Tortoises to DPDT switches on the control panel. From there the DPDT switches draw power from 18 volt DC transformers (MRC Railpower 1370). Each DPDT switch has a bi-polar LED connected to it to indicate the direction of the point rails (green for straight through and red for divergent).
Rich
Alton Junction
Aikidomaster Instead, there is one wire that is insulated and another exposed wire that is entwined around the other one
That's just coax. The center conductor is most likely the positive, and the outer braid would then be the negative.
I forgot to mention that the power supply in question is very much like the Digitrax PS 14. What I did with the Radio Shack power supply was to cut off the end that is like a plug. I then, split the wires. One for positive and the other for negative, These were then connected to separate power strips inside the control panel. It works great!! But, the PS 14 does not have 2 separate wires when I cut the end off of one of them. Instead, there is one wire that is insulated and another exposed wire that is entwined around the other one. So, I can not use it like the other one.
Help, please!!