I'm putting together an HO scale signal bridge using LEDs. I am having a heck of a time making good solder connections with the magnet wire I need to use because there are so many LEDs in a small space.
Does anyone have any hints for working with magnet wire, particularly soldering it? Thanks.
It takes an iron man to play with a toy iron horse.
Magnet wire has an enamel insulation coating that must be removed, or solder won't stick to it. A very fine grit emery cloth is good for removing the enamel, but don't put too much pressure on the wire or it will snap.
Pick one of these up at radio shack. Inside the handle there is a small stripper that will remove the insulatoin from the magnet wire or wire wrap wire. Soldering will be much easier. Also make sure the tip is very clean and the wattage is no more than 15.
http://www.radioshack.com/product/index.jsp?productId=2103243
Springfield PA
Think about using #30 wire wrap wire instead of magnet wire. Easier to handle and strip for solder.
I don't know how you are going about it, and maybe you don't need this information, but what I do is work with the signal heads first. I glue in the LEDs and cut the leads to length (really short), then solder the wires on. (You must remember which LED lead is positive of course.)I also use Tix Flux when soldering the wires to the LEDs. I know it is a form of acid flux, but after soldering all the wires, I wash the heads with soap and water to remove all the acid residue. (The Tix flux is liquid and seems to do a better job than rosin flux, which needs to be removed with 91% isopropyl alcohol before filling the back and painting.)After that I fill the backs with epoxy and paint them. Once the heads are all wired and painted, I attach them to the signal or signal bridge and then route the wires.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
Mr.B.
David beat me to it. The little blob of solder will remove the enamel coating and tin the wire in one stroke. I use my standard 25 watt soldering pencil with a really fine tip.
Be careful when routing the wires that you do not scrape the coating or you will have a potential short.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
Forgot one thing.
Don't kink it!!! Kink = breakage.
At the Ngineering website there is a page that explains how to tin, solder, and work with magnet wire: http://www.ngineering.com/wiring_tips.htm
This information was super useful for me when I installed lights on my Trackmobile.
TONY
"If we never take the time, how can we ever have the time." - Merovingian (Matrix Reloaded)
Thanks. And now for something completely different.
I've been trying to connect two LEDs in parallel, one red, one green. Each one independently checks out fine, but together, only the red one lights up. It now appears that the red led is taking all the current, while the green one "starves" and won't light. My hypothesis of poor wiring due to my inexperience with magnet wire turned out to be wrong.
Is this normal, or do I have some very off-beat LEDs? They're from Miniatronics, and all came in the same package. Any idea of what I should expect from the yellow ones?
I'm guessing that I should re-think my wiring diagram, and try to go with series wiring rather than parallel.
It all goes back to the flow of electricity to the least resistance thing. Hooked in parallel the flow will go through the easiest pathway. In series the flow only has one option on which way it should go.
Parallel works best if each LED has its own resistor. And if the LEDs re evenly matched - different color ones often have varied characteristics. You also need to supply enoug voltage. Say the red LED has a forwrd voltage of 1.8 volts, adn the green is 2.2 volts. If you supply 2 volts, the red one with light but the green one won't. You need at least 2.2 volts and an individual resistor on each LED to 'tune' the proper current. Red LEDs also tend to be brighter at a given amoutn of current, so typically a larger resistor is used on the red to reduce the brightness so the two are equal.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Thanks. I pulled some unused LEDs out of the package and played some breadboard games with them. Turns out the voltage drop across the green and yellow leds is a bit higher than the reds. I can parallel-wire green and yellow, but not red with either.
I don't want to provide individual resistors, because I'm trying to minimize wiring inside this 10-LED signal bridge. Instead, I've come up with a series circuit which I'll start wiring up this week.