I was wondering if anyone had ever replaced the headlight on one of the proto 2-8-8-2 usra's. Have one that is burned out. I am assuming it is an LED inside the headlight but it has to be a pretty small one. Wanted to see if anybody knew before I had to tear it down twice. Jim
Fortunately, I haven't had to enjoy that pleasure, yet. Mine is an early run and it is an incandescent lamp, probably 1.5 volt. I assume you are asking about the HO version?
LL_Proto_Y6 by Edmund, on Flickr
If (when?) I'm faced with the task I would use an LED as a replacement. I recall installing a decoder in the L-L Nickel Plate Berkshire and I didn't replace the bulb with an LED and the headlight housing melted from the constant heat of the filament!
LL_Proto_Y6_0001 by Edmund, on Flickr
Good Luck, Ed
Is yours the N&W or the usra?- Mine is a USRA I have heard both 3V and 1.5V on these. Mine is a Life Like before the buy out. The tender light is LED with a light rod so I assumed the front one was LED too. Hated to tear it down without having the proper thing. Most small LED's are kind of sideways too.
Mine is the N&W version. It was the first locomotive that I installed DCC sound into. Haven't run it in a while, I'll have to dust it off and get 'er on the main.
Some of the pre-wired surface mount (SMD) LEDs would fit into the headlight housing. You would have to use a clear cement to get it to stay in the housing, though. I use canopy glue since it sets slowly and you can be sure the LED is aimed just right before it cures.
I goofed up on the Life-Like 2-10-2 and forgot to put the resistor on the headlight wire. Poof! Oh, wow, what a job it was to get to THAT LED. It is practically in the center of the boiler. The Berkshire is easy, right behind the smokebox front.
Good Luck on your task.
Ed
I am looking at some SMD Led 0603 They look to be between 1/16 and 1/8 in size. wonder if that would work
I believe 0603 is a good size for locomotive headlights in HO. I have put several of that size into brass loco headlight housings. The plastic housing will be a little easier since you really don't have to worry about shorting to the brass.
I've had luck by dipping the led with the leads in a clear, tacky glue. I sometimes use Aleen's clear tacky cement or lately I've been using Locktite Go2.
I think for headlights It works best to have the leads soldered 90° to the LED. Some come wired with the leads in-line. You don't want to have to do any twisting as that may break the solder bond or the pad off the LED.
Then I place a dab of the clear cement into the headlight housing and allow it to get slightly firm. Then place the LED and test it with a battery and resistor or, I have a handy LED tester with clip leads. This allows you to make sure everything is working and lets you know which lead is positive unless it already has a coded wire. But you want to be sure to set the LED so it looks right in the headlight. One of my early attempts has too much light shining up but not enough forward.
Of course you're going to have to see what voltage and what polarity is coming off the board and choose a good resistor for it. The tiny SMDs can be pretty bright.
I just made some PRR dwarf signals using 0402 size and those things are really small
PRR_PL1 by Edmund, on Flickr
gmpullman Of course you're going to have to see what voltage and what polarity is coming off the board and choose a good resistor for it. The tiny SMDs can be pretty bright.
Rich
Alton Junction
Ok that looks like exactly what I need then- looking at some from China on ebay that have presoldered leads- They are a 3V so that should be what it sounded like what I needed in this application- I will need to get some resistors for 12V apps. Thanks everybody for all your help. Jim