[?] Would it be safe to install LED’s into those cheap Model Power/ Bachman signals? LED’s dont produce heat right? Im just looking for a cheap way to add signals to my layout! I have a couple of brass signals and you know what they are priced !!![B)]
I’ve done this with Model Power dwarf signals and multi-track signal bridges with no problems. You’re right, an LED does not get hot enough to have an effect on plastic, and the LEDs can be held in place with any type of silicon sealant.
be sure to use a 1/4 or 1/2 watt resistor with the LED…i have found that they work best with a resistor in the 180-300 ohm range…you can get the resistors form any electronic parts supply company…i learned the hard way about LEDs…if you connect them to a power source directly without a resistor, they will explode in your hand…it’s like a holding onto a fire cracker, lighting the fuse and forgetting to throw it on the ground…OUCH!..I use LED’s for all my target signals but i don’t use plastic even though they do stay cool enough for plastic like you asked…i like to scratch build the searchlight targets from brass rod, styrene, Campbell’s HO scale brass ladder, and balsa wood …here is a website for scratch building targets…http://www.gatewaynmra.org/articles/napper-sig.htm Chuck[:D]
CWCLARK
Hey CW, what do you use for a signal power supply and what voltage. I am starting to plan for signaling and need some ideas.
Thanks, REX
rex…go to the site I just mentioned in the previous post…thay have an awesome train detection circuit that they show how to build step by step…it will require nand gates and be sure when you order them you get the PIN type…not the DIN type…they have a listing of every part you will need to build the circuit…it will require a 5 volt, and a twelve volt power supply that has if i can remember right a 2.2k ohm resistance…it is a big article but shows every step by step feature in building them…i’ve build 8 of them so far and will be installing them as soon as i build the targets…the circuits take about 3 hours to build each one of them…Chuck[:D]
Thanks CW.
Very good site with great info and ideas. It will be a big help.
REX
No more $40 signals for me!!!
actually…the scratch build signals are not even $5.00 a piece…and the biggest expense there are the LEDs…
Here’s the quick and dirty calculation for a LED dropping resistor. Subtract 2.2 from the voltage you are using. Divide that answer by 0.02. That’s the value of the resistor in ohms. Use the next largest standard resistor value. A 1/4 watt resistor is fine.
This month’s SCALERails, the NMRA Bulletin, has a great article on making working signals. They use IHC target faces, but you could make your own. The LEDs have a + and - lead, so you have to observe polarity, the cathode or - side of the LED has a colored spot or the lead has a wide spot. Be careful not to let bare wires touch your brass signals and cause a short. Also, in the article they have a neat way of mounting the signal using an IC socket and connector.
LED’s don’t generate any heat during use. BUT, if you are using a series-wired resistor, locate the resistor outside any plastic housing of the signal itself. The resistor WILL generate heat – that’s where all that excess voltage goes. The amount of heat will depend on the size of the resistor and the supply voltage. Best bet is to use a transformer that supplies only the voltage the LED requires.
I made this signal and it was cheep http://home.cogeco.ca/~rpaisley4/Flashers.html
Ken
model train stuff.com lol its got lots of good stuff
I use 1.5mm axle lead LEDs in IHC heads. I use 5 minute epoxy to hold the LEDs in. The epoxy fills out the opening and makes a nice looking lens. My signals are powered my a 12V supply and have 470 ohm dropping resistors. I make sure that the resistors are under the layout top.
Nick
Hi all
As an aside to this topic
I noticed some square LED’s that might be usable as
low speed shunt lights these are a yellow light that allows a loco to go into say the loco yard while the main head is red.
have not worked out how to fit a tiny hood to one yet but masking a small
6" diameter lense for it and painting the rest black should sufice if a small hood can be atached without damadging the lense.
Or how about a signal marker light using a blue one.
these two are generaly halfway up the mast.
just thought not sure if it would work.
regards John