Power supplies

I was shopping for a power supply. Turns out I already have several on hand. On ebay there is a PS514 for digitrax currently bid at 4 bucks and 7 bucks shipping. It will likely go for around 30 total. Or you can buy one for about 45 from the hobby shop. I sent an old laptop to the shredder but kept the power supply. It is a Toshiba 19v rated at 9.5 mps. Much more than I will need and its free other than adding an inline 5a fuse.

Also on ebay, if you look for laptop power supplies, you can find 20v, 4.5 amps for less than 10 bucks with free shipping.

I actually contacted Digitrax to verify that these were acceptable. No problem. So how many of you use laptop or computer power supplies for your railroad?

At present, my plan is to build a metal rack for all the DCC equipment and power supplies and put a couple computer fans in there to keep the temps down.

 

I have been using the 12 volt type to power LED lighting on the layout.

http://palisadecanyonrr.blogspot.com/search/label/LED

 

A computer power supply sounds like a good plan. One power supply for all the peripheries. I just happen to have a technerd buddy who used to build computers so it would be free also. And it could supply the power to my cooling fans. Good plan!

 

I use a computer power supply for all 12v and 5v accessories. I use the 3 wire R/C servo extensions and Y's to power LED's and Arduino controllers. I make my own extensions and use the black wire as common, red 12v, white 5v. When I need a new connection I add a Y and go on.

 

Are you using the RC servo's to power switch machines? They are cheap and appear perfectly suited for the job.

 

Count me in as one who uses an old computer power supply. I epsecialy like the 5v on the tortoise switch machines. Throws them nice and slow.

-Mike

 

Steve, no I don't, my switches are Kato Unitrack. I do use the servos for crossing gates controlled by an Arduino. I have seen posts on another forum demonstrating their use.
If I can find the thread, I will post it.

Harold

 

This is one of the threads I referred to. I also recollect someone posting a video, search for "servo turnouts" in YouTube.

http://www.nscale.net/forums/showthread.php?32190-Remote-turnout-servo-control

 

Yeah, servo's have a lot of uses on a model railroad. Especially at 10 for 25 bucks. If you could slow it down you could have a scale figure turn or walk past a window. Or maybe lower the water pipe on a water tower and make it go back up after filled? I am chest deep in benchwork and room prep but it is definitely something I want to play with. We likely need a new thread cause I am sure a lot of people have come up with animation and uses for things from other hobbies. My diorama has become like the plague. Spreading before I get the first track laid. It is now a 10 by 13 shelf railroad with potential for massive expansion.

 

You have to be carefull with Switching type power supplies (the type now found in almost everything). These are based on very high switching frequencies, charging an output capacitor. These types of supplies have lessor capacitance than Linear power supplies (the heavy ones, with Transformers in them). These needed BIG capacitors to keep the Ripple down so the 'average' DC voltage was cleaner.

The issue is when there is a short, the Hold Up time is very low, usually well under 100 milliseconds (100 ms). This means if the track short current exceeds this time, the power supply will Current Limit REAL fast to near 0 volts. It will recover VERY fast, after the short is removed. So, the Electronic Circuit breakers in the Booster or good breakers like DCC Specialties not disconnected the short fast enough, the Switching type supply may collapse first.

Most work OK though. Just be aware. The Linear type or just plain Transformers like NCE and Digitrax use will deliver all the current you want, for a LONG time, before overheating. Total reliability.

 

I expect the laptop PS will suffice until I start operating more than a few loco's at once. If I expand beyond that, I think I would buy the PS2012. I just didn't want to add another $150 to my bill this time around. The laptop supply is big and heavy and barely fit the laptop carrying case. But it is a totally sealed unit so a cooling fan will be of dubious value. I will put a 5 amp fuse on it.

 

I've been successfully using a 12-volt (13.8v) tractor battery with a trickle charger. Power is sent to various areas via power busses with lighted switches and fuses. These circuits include DCC supply for the Zephyr, DS64 stationary decoders, occupancy detectors, etc. a 12-v buss also runs around the entire layout. It works well, costs, little, is not interrupted by power outages, needs no filtering, introduces no hum, can furnish power to every need of the layout, and is safe. Don't knock it till you've tried it.

Capnsandy