Re: HO Headlight Suggestions?

in article z3pGb.187079$ snipped-for-privacy@twister.rdc-kc.rr.com, Frank Eva at snipped-for-privacy@wi.rr.com wrote on 12/24/03 3:12 PM:

They are using a regular "blue" led with the white phosphor, then an amber colored casing to absorb any extra blue. You can achieve a similar effect with a regular "bright white" leds and Sun 8410 (daylight) filter material, or even amber glass paint.

I've not tried the new miniatronics clear case white (yeloglo) which claim to be incandescent colored.

There is a company, ledtronics, which is a supplier from whom you can't buy, which makes both Pale While and Incandescent White leds. I obtained samples at one time. They were pretty good and had clear cases. One of the samples (5mm) was cylinder shaped with a flat front: almost exactly the size for an F3/7/9 headlight. Too bad I could only get one and I've seen them nowhere else.

You can get ultra-bright leds of various colors, including white and they can be exceedingly bright, indeed if run at their full rated voltage. The "bright whites" I got from Allied Electronics left after images if looked at straight on. Many of these leds, however, have a fairly narrow light projection: 13 to 20 degrees, and are quite dim off axis. But take care with the resistors used to limit the current: if the voltage is too high, the leds burn out quickly. If I calculate, I get 620ohms or so for my 4v leds and digitrax decoders; but I use 820ohms to allow for a safety margin and the white ones are still very bright.

I still like LEDs for their coolness (not in the sense of hip, but rather temperature) and longevity.

Ed.

Reply to
Edward A. Oates
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That was pretty much implied later in the same post: the semiconductor blue emission excites the phosphor to produce sorta-white light, and then the case coloring takes some of the blue out of that mixed bluish-sorta white, making it more yellow (a tad bit too yellow for my tastes, but what th' heck). This is much simpler and more straightforward than experimenting with multiple semiconductors and/or multiple phosphors all in one device to get the same effect.

There are a vaaast variety of LEDs made, most of them not re-packaged for marketing to hobby shops. You can find (in the DigiKey catalog, for example) LEDs of any given color that are so bright it hurts to look at them.

Reply to
Richard Schumacher

explain which

"microlamp"?

For scrolled posts, can't you just look here:

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Reply to
Mac Breck

The GP60s have black paint applied at the factory, and if I recall correctly, the paint is on the sides of the pipes, until they reach the spot where the light bulb is. Why would they paint the sides if this actually absorbs light rather than transmitting it?

It certainly helps explain why it's so difficult to get decent light from the cab headlamps!

Reply to
Frank Eva

I would like to know where you can get colored ultra-brights! The colored LEDs I've used are anything but bright!

I'd like to try a red one in a lamp of a dual-lamp Athearn Genesis F unit. However, I've read that LEDs don't work well with special lighting routines, like Mars lights. Is that your experience?

Frank Eva Digital Railroader

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Reply to
Frank Eva

I know what was said - my point in asking this question was that the amber coloring in the case has the effect of reducing the amount of light transmitted, and if it wasn't needed - as in they could produce an appropriate yellow light without it - not using the coloring in the case would result in a brighter light. Therefore, IMHO, it is simply not possible to produce a reasonably priced 3mm LED that gives a prototypically yellow light in its natural state.

Frank Eva Digital Railroader

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Reply to
Frank Eva

NCE announced something like this over 2 years ago - the LED was used in the auto industry and at the time, was not available in a size appropriate for model railroaders. NCE still hasn't been able to get them, and the last time I inquired about them six months ago, they had no idea when they would be available in 3 or 5mm.

Frank Eva Digital Railroader

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Reply to
Frank Eva

Microlamps are those ultratiny ones that you look at and say that there is nothing on the end of the wires but a small dab of glass that is holding the two wires together. They are very tiny and do produce a fairly small spot of light. They do cost a bit more than the grain of rice sized bulbs and are usually only available in 1.5V input voltage. Depending upon your newsgroup server, you should have a good month's worth of posts on a particular subject. Your daily downloading of the headers for the posts will end up with your having the old parts of the thread still in your machine and setting the viewing of the newsgroup to all posts rather than just new posts will show all of the posts of the threads that you have been reading. In addition, there are several web places that also provide access to the newsgroups and some of them you can even post to a newsgroup with.

-- Bob May Losing weight is easy! If you ever want to lose weight, eat and drink less. Works evevery time it is tried!

Reply to
Bob May

Light pipes work by the reflection of the air/material total internal reflection and any paint or such will reduce that reflection. The angle at which this starts happening is called the Brewster angle. Slight grazing angles will cause a total reflection with no light loss and at the Brewster angle, the light will start coming out from the interior to the air. Painting the plastic turns the total reflection to whatever the paint's reflectivity is and that is why the light output of a light pipe dims when it is painted. Please also note that if the surface of the pipe isn't smooth, there will be leakage of the light from the Brewster angle being exceeded in those local spots, letting the light out.

-- Bob May Losing weight is easy! If you ever want to lose weight, eat and drink less. Works evevery time it is tried!

Reply to
Bob May

Then Life-Like made a big mistake by painting the pipes in their GP60! Sure, it keeps the cab dark, but at the expense of the light transmitted through the headlamp/numberboard module.

Frank Eva Digital Railroader

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Reply to
Frank Eva

in message

sides. If you paint

I recall

they reach the spot

this actually

SWAG: Rays that hit the sides and back and get reflected by silvery or say a mirror finish paint (chrome paint?), would add to the light coming out the front, but probably produce a softer edged beam. Absorbing those stray rays by using black paint on the sides and back may result in a slightly cleaner edged, but slightly dimmer beam.

Somebody would have to experiment with the various methods(bare LED, silver/chrome back and sides LED, black back and sides LED, black sides and silver/chrome back LED), to see which they like better, and if it makes any noticable difference to them.

Reply to
Mac Breck

Has anyone tried the new golden white LEDs available at Tony's that say they have a crystal clear color when not on?

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Thanks, Scott

Reply to
Scott

How about tossing the light pipes and putting LEDs where the lights belong? I haven't tried ditch lights yet, but for headlights this approach works fine.

Reply to
KTØT

The variable light output routines, like MARS and GYRA don't work well with anything but the NCE decoders with the "LED" bit in the light funcntion CV, in my experience. LEDS are sort of "off/on" devices and the voltage swings must be small to just dim them a bit. Maybe other decoders have that type of function now, but I've not seen them.

When you buy LEDs, look for "ultra bright" in the description and maybe tried for clear lenses instead of the colored ones. The problem with the red light in the genesis, is that it is a grain of rice bulb and thus tiny. I don't see a good way of using LEDs in place of the installed bulb.

Ed

in article wOFGb.188166$ snipped-for-privacy@twister.rdc-kc.rr.com, Frank Eva at snipped-for-privacy@wi.rr.com wrote on 12/25/03 10:14 AM:

Reply to
Edward A. Oates

The problem here is that the light pipes and numberboards are one piece - remove one and you remove all. Then, even if you could separate the two, how would you hold the LED in place so that it could illuminate both the headlamps and numberboards.

Frank Eva Digital Railroader

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Reply to
Frank Eva

I prefer NCE decoders, but I never used one with an LED set up to represent mars or gyra lights. I'll have to give this a try.

There are colored LEDs that are called ultra-bright, but they are anything but. I have not found LEDs targetted at the model railroad industry that offer colors WITHOUT colored cases.

I have replaced the gow bulbs with 12 volt incandescents, modifying the original headlamp by drilling out the hole a little larger. These parts could be drilled out to hold a 3mm LED. Haven't tried it yet, but I think it would work.

Frank Eva Digital Railroader

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Reply to
Frank Eva

Minatronics sells these in 5-packs and they include resistors. I plan on ordering some, ASAP!

Reply to
Frank Eva

"Frank Eva" wrote in message news:Za_Gb.190008$ snipped-for-privacy@twister.rdc-kc.rr.com... : "KTØT" wrote in message : news:bYYGb.9803$ snipped-for-privacy@twister.rdc-kc.rr.com... : > How about tossing the light pipes and putting LEDs where the lights : belong? : : The problem here is that the light pipes and numberboards are one piece - : remove one and you remove all. Then, even if you could separate the two, how : would you hold the LED in place so that it could illuminate both the : headlamps and numberboards. : Frank, I'll give it a try on one of my engines. I have heard someone say he drilled a hole into the LED to connect fiber optics - might work with a light pipe too. I suspect that best transmission into a light pipe requires a very close connection - drill a hole for the LED into the pipe or vice versa.

Reply to
KTØT

The problem with Proto 2000s is that the light pipe is in the shell and the area where the LED is held is in the chassis (and yes, when the shell is fitted to the chassis, the LED winds up directly behind the light pipe. Now, it would be possible to do what you say, but unless you don't use any cement to hold the LED in place, you'll have to use extra long wires so that when you take it apart, you don't have to disconnect something to work on it. I'm also not sure if the light pipe is thicker than a 3mm LED???

Reply to
Frank Eva

I never buy leds targeted at the MR hobbiest, but I may try the new miniatronic yeloglo stuff. Maybe they are the Ledtronics incandescent white LEDs I referred to in a prior post. I really liked the samples I got from them: quite bright and with 30 milliamps through it (via my Sload LED tester), they are real bright, only slightly yellowis with a clear lens, either domed or flat.

I've seen clear lens red, green, and yellow LEDs at Fry's out here in CA; I usually buy stuff from Allied Electronics online.

The GOR (even smaller than GOW) bulb in Genesys Santa Fe F7 is paired with a white one in the same housing. I just used the bulbs as is with resistors. Pretty dim, but serviceable.

Ed.

in article 2g_Gb.190011$ snipped-for-privacy@twister.rdc-kc.rr.com, Frank Eva at snipped-for-privacy@wi.rr.com wrote on 12/26/03 9:31 AM:

Reply to
Edward A. Oates

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