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Hello,

I'm looking for 3mm warm white LEDs to replace my standard white LEDs (which are too blue), to be fitted to a Hobbytrain Taurus but there are many uses for such an LED - can anyone help?

I need 10 (2 for each Taurus) and the only people I can find are Express Models who seem to be charging £1.40 per LED!!!
There is no way I'm paying that for LEDs...

This long exposure shot shows the true colour of the Taurus lights...hardly blue-white!

1116 236-9 mit einem Regionalzug bei der Einfahrt in Payerbach-Reichenau. (10.2.2006)
Picture: Franz Lackner
http://www.bahnbilder.de/

I wonder if I could put yellow ink/paint/film on the current white LEDs to make them a better match? While on the subject has anyone thought about or tried smaller LEDs (perhaps surface mount? SMD LED) so that perhaps each light could be done independently (in the Hobbytrain Taurus there is a plastic conduit that takes the LED light to the three headlights and cab, so trying to fit something for red tail lights is proving really difficult because there is no room with the existing conduit in place!

Any advice warmly welcomed!

Goedel
 

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Hi

I've used 3 mm Golden White LED's - LED-3GW from Lichfield Station in the USA. http://litchfieldstation.com/lobby/index.htm
These cost about 75p each, the postage is very reasonable and their service is excellent. I used a 1K resistor and they are still very bright. The colour is similar to that of a tungsten bulb. The LEDS have an orange colour when unlit.

Hope this is useful


Best regards
 

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I have an idea that John at Broomsgrove Models stocks the golden white LED's.

If you add yellow to the "blue" White LED's they end up greenish !
 

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Thanks for the excellent suggestions Oscar and Howzatt, although the ones on eBay.es were 8000mcd and possibly too bright even with a small resistor?
QUOTE (dbclass50 @ 14 Jul 2007, 07:05) <{POST_SNAPBACK}>I have an idea that John at Bromsgrove Models stocks the golden white LED's.
Thanks Brian, he does indeed at 80p each and rather luckily his minimum order value is £8 which is very convenient as I wanted ten. I'll post some pictures when they've been fitted to allow comparison/contrast!

Although 80p is still expensive for an LED, esp. in a colour that is presumably used in vast quantites for ordinary room lighting given the more natural (or perhaps I should call it 'less artificial' because the sun has a very wide frequency range..) colour. Perhaps it's my own fault for needing such a ridiculously small quantities...righto - I'm off to find two, yes just two red SMD LEDs


Goedel
 

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Here is the result after the first LED was installed. (Please excuse the ghastly pantographs on two of the Tauri - they will soon be replaced!)

From left to right we have:

Minitrix 1116 with bulb, with some lubrication oil on the body so it appears rather shinny in places
Conrad/Hobbytrain 1016 with new warm LED, front coupling removed
Conrad/Hobbytrain 1016 with old blue-white LED



...it is clearly a major improvement (
) but obviously LEDs still have someway to go before they look as warm as bulbs! (the new LED doesn't look quite so yellow in real life as seen here) It should be noted that the models are on DC track set to about 3V (any higher and they will begin to move!) so the colours could well vary slighty at the full 12V from as seen, plus more light in the cabs. When I have DCC in the near future then the lights will always be on at full power!

To me the modification was worth it even if the soldering was a bid fiddly (there is a surface mount resistor very close to the LED legs on the circuit board and this can become disconnected when the solder melts)...at least the bodyshell lifts off without any screws, and the circuit board can be removed by sliding it and lifting, again without undoing any screws (perhaps I should add pictures of the proccedure?).

The headlights do look much more close to real life; I can think of several other models that could do with the treatment including my Fleischmann DB BR185 (7385)and SBB Re 482 (7386) where the superdetailing extends to everything but the LEDs!



The next challenge is making some red tail lights from SMD LEDs and some wire...even more fiddly but worth it for the BLS Cargo Taurus which will operate a push-pull train!

Goedel
 

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Grat job Goedel.

To coalculate the led resistor needed, i have a very simple trick. I use a variable resistor (i don't know the name in english. In spanish is called "potenciometro"); when the led brightnes is the correct, i measure the variable resistor with a multimeter and i intall the correct resistor in all the lights. (in the end i will learn english with all the explanations
)

REgards from Spain,
Oscar
 

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QUOTE (goedel @ 14 Jul 2007, 18:55) <{POST_SNAPBACK}>Although 80p is still expensive for an LED, esp. in a colour that is presumably used in vast quantites for ordinary room lighting given the more natural (or perhaps I should call it 'less artificial' because the sun has a very wide frequency range..) colour.

Goedel

The LED's used for commercial & domestic lighting are still a bit on the "harsh" side to look convincing as halogen or tungstone lamps. The colours used are excellent for colour rendering, hence the fact that they are not "quite right" for model use.
 
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