Decoder install

[rrinker]

      Hmm, no one mentioned stripping the wires with their toe nails, I must be the only one.

 

 You're the only model railroader thin enough to reach his toes.

              --Randy

[jondrd]

 Lee,

     You might want to peruse Train Control Systems website, they have a section called "Installations"=both for HO and N gauge. People send in photos and in most cases a brief description of what they did to complete install. Some of the photo and text submissions are better than others. I'm still at the stage where a well written description helps, even with photos.

     Additional sources of supply for model train electronics is Miniatronics they advertise in MRR.

     The soldering of tiny decoder wires to loco: tinning the wire ends helps getting a good connection.

     You should exercise care when soldering wire to LED leads as you don't want to apply so much heat you wipe out the LED. A neat heat sink is one of those tweezers you press to open so that it clamps onto the lead.

     Hmm, no one mentioned stripping the wires with their toe nails, I must be the only one.

 

[bandmjim]

I get my shrink tubing from Home Depot, GB 3/32 tubing  24 AWG part # HST-093 found in electrical section, red package of eight.   I use my solder gun to heat and shrink, found this works fine for me, as long as I remember to put the tubing on before soldering......

[yankee flyer]

OK good stuff everone.

This input gives me a lot of help in what I need to look for. Yes the loco motor leads are color coded, I have multi meters, and the decoder comes with a schematic. I'm sure the installation will be OK, but I learned a long time ago that when you discuss a problem with others the problem becomes clearer.

Happy railroading.

Lee

[MisterBeasley]

My LHS stocks the very small shrink tubing that works for decoder wires.  I've also ordered it online, but like most of that stuff, I wait until I have a big enough order to make it worthwhile to go online.  The shrink tubing from Radio $hack is still sitting in my "what am I going to do with this junk?" box on my workbench.  As someone said, it's way to big, and doesn't shrink very much, either.

[wjstix]

this is kind of relevant to the original post:  Do decoders come with instructions about how to hardwire them to the engine?  Like, with visuals or descriptions of which wire goes where?

Yes, as with anything else, some companies instructions are clearer than others.

For No.2 you could look at a product called "Liquid Tape" IIRC, it's a black rubber in liquid form...kinda like black paint, you paint it on the exposed wire and it when it dries it's insulated. It's a bit flexible once dry so that's nice. But I usually just use small pieces of black electrician's tape.

[jeffrey-wimberly]

this is kind of relevant to the original post:  Do decoders come with instructions about how to hardwire them to the engine?  Like, with visuals or descriptions of which wire goes where?

All the decoders I've used come with a wiring diagram showing what wire goes where similar to the photo below.

[rrinker]

 The wires are color coded, usually. The wires in the loco might not be - most of the time they aren't.

 Black and Red are the track power inputs to the decoder. Orange and Gray are the motor outputs from the decoder. Blue is the function 'common' - one side of every light bulb or LED connects to the blue wire. Blue is the positive lead. White is the front light - Function 0 Front - F0F. Yellow is the rear light, F0R.

 Orange is the 'positive' lead of the motor - if the loco ran in the correct direction on DC - forward when the right-hand rail was positive, then the orange decoder wire connects to whichever motor terminal previously connected to the right hand rail. Gray goes tot he opposite motor lead. Red is nominally the right hand rail, black the left.

 

                                 --Randy

 

[DeadheadGreg]

this is kind of relevant to the original post:  Do decoders come with instructions about how to hardwire them to the engine?  Like, with visuals or descriptions of which wire goes where?

[rrinker]

 1: For stripping, I usually use my fingernail. The insulation comes off the decoder wires pretty easily.

 2: Shrink tube, it's far neater than any tape and stays put. You need fairly small diameter stuff - it should slip easily over the wire but it shouldn;t be big enough to shove 5 wires through, it won't shrink down enough. A GOOD supply place like Mouser will have a pack of all the same size - the bundles at Radio shack have a couple usable pieces and the rest are huge - maybe you can use them for layout wiring. The RS stuff also seems to take more heat to shrink. To allow the heat shrink to fit, use linear splices on the wires - Don't just take the two ends and twist them together, lay them in a line with the stripped portions overlapping and wrap those around each other (easier to see it than to put it in words). When done it should be wire--bare area of two wires twisted---wire all in a straight line. Solder the joint, then slide the shrink tube over it and shrink in place (test before shrinkign all the shrink tubes!).

 3: No, one resistor per LED. Theoretically since the F0 function is by default directional, it's not possible for both LEDs to be on at the same time - however it can be MADE non-directional.. so play it safe, 1:1 ratio of LEDs to resistors. From a big supplier Like Mouser, resistors are like 2 cents each.

 

                          --Randy

 

[richg1998]

I use Klein wire strippers. There are two types. The one you want strips #22 to #30. Most DCC wire is #29 or #30. Small difference. The other stripper handles #10 to #18 for your layout. Search Google for Klein. Maybe Micro Mark. I know Litchfield Station has the set for 22 to 30 wire.

I use  1/16" shrink for most of the decoder wiring. Sometimes I use 3/64" shrink. I use Kapton tape for insulating. Very thin and strong. Thinner than electrical tape. Might make a difference. I order all my stuff from Litchfield Station when I order the decoder. Free shipping over $75.00. I have a heat gun but sometimes use a hot soldering iron. I have a Weller soldering station with variable heat. Electrical solder with rosin flux. No hardware store stuff.

Sometimes I paint the wires between the loco and tender with liquid vinyl tape. Makes them look like hoses. The liquid tape is also good for insulating solder connections.

For the lights, use 1k 1/8 watt resistors. Stay with one LED or lamp, one resistor. Make sure you have a voltmeter, amp meter, ohm meter for testing. I see a lot of frustrated modelers who try to trouble shoot the trains without a meter. I use my ohm meter at least three times when checking out my wiring and I have been an electronics technician for many years. Decoders can be expensive, plus lost time and expense if you have to order another decoder.

Remember, some say it is easy but it is easy for those who have done this a few times.

Rich

[conrail92]

Radio Shack will sell it, most hardware stores might but not sure if they sell ones that would be small enough for small electronics.

[yankee flyer]

Thanks all.

I was wondering if there was shrink wrap small enough and where to get it,  my wire strippers are too big for these little wires.As for shrinking, the wife's hair dryer might work.

Tomorrw I'll see if Radio shack can help.  I also need the LED and resister.

Happy railroading.  

Lee

[MisterBeasley]

I thought of shrink wrap, but only way i could think of heating it is open flame, which I thought wouldn't work well with delicate componets. How do you heat it?

I hold my soldering iron beneath it, very close but not quite touching.  That's enough to shrink it down.  If your shrink wrap is too big, it won't be enough, but if you get the thin stuff it will shrink enough to hold.  The pros use a small heat gun, kind of like a small hair drier, but more intense.

[conrail92]

I thought of shrink wrap, but only way i could think of heating it is open flame, which I thought wouldn't work well with delicate componets. How do you heat it?

[MisterBeasley]

All valid replies.  Even the part about the teeth.  But, I had some dental work done and lost the notch between incisors and bicuspids that did a good job on the #22 wires.  So...

Get a wire stripper.  Radio Shack.  Make sure it will do small wires.  You don't want one the electricians use on your house.  That's for #12 and #14 wire.

Shrink wrap.  It's a tube of rubbery stuff that shrinks when you heat it.  You slip a short length of shrink wrap on one of the wires, solder the connection, slip the shrink wrap over the joint, and heat the shrink wrap.  Great stuff.  Much neater than tape.

[jeffrey-wimberly]

I use my teeth to strip the wires. Electrical tape is good for insulating the joints. I prefer the clear type. The resistor will work OK in the common wire if the lights won't both be on at the same time.

[conrail92]

1-- Wire strippers are the best, but some smaller wires can be stripped with your finger nails... Scissors be careful not too cut the wire.

2-- All the locomotive I did where either plug-in or came with insulator caps...Perhaps electrical tape?

3-- I'm not entirely sure but i think a resistor in each would be best, having them share the resistor might decrease the power too much. 

 

[yankee flyer]

Hi Everyone

I'm going to try my first decoder installation and I'm a little apprehensive. This will be a solder job in a EMD SD7. It only has front and back lights.

Questions.

1-- What should I use to strip these tiny wires?

2--Once they are soldered how do I insulate the joint?

3--Can I put one 1K ohm resister in the common wire for both LEDs or do I need to put a resister in line with each LED?

I have some old electronic experience but I've never worked with LEDs.

I really enjoy the forum thanks in advance.

Lee