Rich, You could use a wall wart. Many are 12 volts. For LEDs any wall wart over say 3 volts DC could be used with a proper resistor. I suspect you might have a few laying around from old cell phones, etc.

 

Pete

Rich Lionel made a DC Converter 6-82116 for converting AC to DC, line does up to 10 amps and puts out 12 volt DC and the converter box has a breaker on it.I have several for converting to DC for all my animation and DC lights. Its purpose was to allow its G gauge operators use of the ZW and other Lionel transfomers. I know S and W Train parts has them, try them.

LM2596 DC Step-Down Adjustable Converter Power Module

 

Rich,

 

I am doing it two ways.  12volt wall warts and step down converters http://www.ebay.com/itm/150471...id=p3984.m1439.l2649. Only $7.85 free shipping. (These guys are closed till 2/18 for the Chinese new year.  All their auctions are offline till after the 18th)

 

The Wall wart route is the easiest, because I have a box full of old ones.  I probably have close to 50 LEDs on my Layout now and will add at least another doz before I am done.

 

I started a small blog as a note book to keep these ideas in one place.  I put together this video that kind of explains what I am doing.  The idea behind the 12v LEDs was originally based on using a Malibu light power supply, but with wall warts I don't need to go with the Malibu light system.  I would like to add that anyone who goes with these systems - This is all Home Brew - be careful, your layout has lots of paper product, wood, foams and other flammable material.  Never leave your layout powered up unattended.

 

Rob,

 

You are appealing to my inner tightwad .....  wow that is a good price!

 

-Ted

See my recent post under "How to dim LED strips in passenger cars"; that is the exact module i use. BUT it requires the addition of a rectifier to convert the AC to DC. Rectifiers are readily available from most electronic supply houses even including Radio Shack. I bought mine on Ebay (item #251146524760), 50 for $6.18 delivered.

 

jackson

That's a DC-DC converter, for an AC-DC converter, you'll spend a little more.

 

C:US:3160" target="_blank">http://www.ebay.com/itm/LM317-...me=ADME:LC:US:3160

 

The DC-DC one will require a heatsink to get high currents, especially with a large input/output voltage difference.  The efficiency of the LM2596 drops in that scenario, and the excess energy is heat.

 

Yes, about 15¢.

Rich,

 

i bought these on eBay with the "best offer" of $5.50 each, free shipping, buying 20. From seller anna758595, they shipped them well packed and they arrived within about 10 days.

 

Good luck,

jason

I suspect you'll need to add a capacitor as well.

 

 

You don't say if this is going in a command control system but for DCS in particular these so-called "switching" regulator modules reflect a lot of high frequency cra* onto the track so you'll definitely want to install the often discussed choke/inductor filter.  Even if you don't use DCS today, for the minimal cost of the inductor and an extra minute of assembly effort...

Depending on what you want to do, a simple bridge rectifier from Radio shack will convert AC to DC.   Simply feed the AC in the two leads marked A C and take the DC off the two leads marked + and - (plus and minus).   You can connect it to any transformer.  

 

 

I am using this for building lights separate of my Track power.

Stan, I have two of the step down converters on my layout now.  Yes, those are screw down terminals for the input/output.

 

-Ted 

Absolutely.  And don't forget those mounting holes!  The LM2596 modules (which I do use) have neither.  In fact for things like layout accessories I've fabricated printed circuit boards that simply bring the input/output wires from LM2596-type modules to screw terminals AND mounting holes that take #4 screws.  While there are dozens of connector alternatives, I've found this approach tidy and flexible for the inevitable re-wiring as the layout changes.

 

The switching regulator will require a capacitor filter on the input DC as well.  I have some of those modules, and they don't function well without the cap.

My original thought was something small like used in the Evans design LED's   This would be used for building lighting.  I was thinking of running 2-4 led's off a single converter.

Rich, Besides wall warts you could also use an old power supply from a desktop computer.

One of those will equal at least 50 of the supplies suggested here. I have one in my hand that shows 24 amps @ 3.3v, 12 amps @ 12v and 35 amps @ 5V. Even the NJHRs could light their entire layout assuming it was all LEDs and have power left over.

 

Pete

Running a few LED's, you can use something simple.  Perhaps a bridge rectifier, and a CL2 constant current device, both very small.

Most of your major electrical supply houses can get you 12VDC LED drivers (electronic ballasts for LED lighting.

GE makes one that allows you to dim using a simple flourescent dimmer with 0-15V signal control. Largest is 60 watts. Largest allowable Class 2 category with built in protection. Will run about 149 (at 2.5 per foot) of their LED (which are also nice and  labelled for wet location use)   or about 50 linear feet. 

 

 

 

Or any other LEDS for that matter. Nice about the GE units are the built in resistors. you can cut them to any length and run numerous combinations of parelel and series circuits

There should be a filter capacitor across the output of the bridge rectifier.

This may fall into the discussion of AC to DC conversion...

I'm running a 24v DC Pittman motor on AC track power by using a small simple bridge rectifier. It works OK, i.e. the loco runs fine. But should it have a filter capacitor? Would this effect motor output/performance?

Would a converter as shown above be a better way to get DC power to the motor than a small bridge rectifier?

FYI: I'm talking about a big Pittman motor pulling a heavy standard gauge train.

Thanks,
Bert

If it's working, no reason to do anything more fancy for your Pittman motor in your situation.

 

Don't fix stuff that ain't broke!

Thanks John. That's what I figured but threw it out there in case I was missing something...

K-Line used to add this to their motors. They made up a 500 uf non-polarized capacitor out of 2, 1000 uf polarized ones in series. (2 like terminals such as the 2 +s are connected together, the other 2 go to the motor).  Makes the motor run a bit smoother and gives a small amount of electrical driven momentum. Not that noticeable. Be better if larger capacitors could be fit in. In theory a good idea. I do it on some of my locos which are forward only,then a polarized capacitor can be added to a bridge rectifier driving the motor in one direction. A diode in series can also protect a polarized capacitor with bi directional operation. A lot of ways to do this. A small value  resistor,maybe 18 ohm half watt in series to the capacitor will relieve arcing.

 

Dual motored diesels can be driven in one direction using 2, 6 amp diodes instead of the bridge. This is like series motor wiring without the drawbacks. Each motor runs off opposite halves of the sine waves. A capacitor across each motor can smooth the pulsed current a bit.

 

Dale H

Or just buy something like this 2200uf bi-polar capacitor and there's no need for back-to-back caps.

My loco is forward only and has room inside so maybe I could add a capacitor...

If I add it where does it hookup? Across the bridge rectifier?

The motor does get worked pretty hard pulling heavy standard gauge tin so any mods to get more power and life would be good.

Bert

Across the + and - of the bridge in proper polarity. A backward capacitor will explode as in bang! You will not get more power but will get a little better performance at a low speed. If you get arcing on the wheels add an 18 ohm half watt resistor in series to one of the capacitor leads. The cap should be at least 35 volts as track power can peak over 33 with a PW transformer.

 

Dale H

Thanks Dale. I may fit a capacitor in the next time I service the loco.

Bert