Traintronics signals

Does anyone know the colours of the aspects of Traintronics' colour-light signals? The info I'm after is the frequency of the LEDs in nanometres.

Thanks

Reply to
Jane Sullivan
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Why do you only notice the errors in your messages the moment after you pressed the send button. Of course, I meant to say I'm after the _wavelength_ of the LEDs in nanometres.

Reply to
Jane Sullivan

get one and you've got the other.

freq * wavelength = 299,792,458 m/sec

Reply to
Gareth

Just curious: why do you want/need this info?

FWIW, all the LED signals I've seen use red, green and bicolour LED (the latter produce yellow). They look good, but are not "accurate" compared to the real thing.

wolf k.

Reply to
Wolf K

Because I want to see how accurate the colours are. I am fed up with seeing the wrong colour green on model signals.

Reply to
Jane Sullivan

Life's a trial sometimes, isn't it?

Possibly THE most hilarious enquiry (and reason) ever posted to this newsgroup.

Thank you for making my day.

I presume you are busy this Sunday afternoon drilling out n-Gauge boiler pipes?

Reply to
Brian Watson

I don't understand what you're trying to say. People complain if the livery of their locos or coaches is the wrong colour, but you don't care that your signals are the wrong colour.

Reply to
Jane Sullivan

Some years ago a rep from MARL (UK LED manufacturer) was explaining how they wuld really like to supply replacement lamps for, e.g., level crossing warning lights, but the regulations governing their installation were written such that it was impossible to do it economically with LEDs due to the wavelength of the existing bulbs.

MBQ

Reply to
manatbandq

What's so funny about it? We all strive for accuracy in one way or another. Some obviously set lower standards for themselves.

MBQ

Reply to
manatbandq

That was then and this is now!

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Reply to
Jane Sullivan

The precision of this answer - 9 significant figures - is rendered somewhat spurious by the fundamental flaw. That figure is the velocity of light in a vacuum; the figure for the velocity of light in air is about 3 parts in 10,000 slower*, i.e. the equation above is (for any practical purposes, i.e. for air-breathing humans) only correct to the third SF.

*As far as I can ascertain, about 2.9971 x 10^8 m/s rather than 2.9979 x 10^8 m/s. Further precision is pointless as it varies with air pressure and temperature.

David

Reply to
David Littlewood

I've noticed that the shade of green on incandescent traffic lights in my town varies, sometimes within the same intersection. The we have LED ones, which are presumably all the same, but different from incandescents.

Reply to
MartinS

Newer traffic lights in my part of Canada use high intensity LEDs, as do emergency vehicles, school buses, etc. Many cars and most trucks have LED stop, tail and indicator lights. Railway crossings locally still use flashing incandescents, but have a loud electronic warning bell.

Reply to
MartinS

I thought that the figure 299792448 was a _DEFINITION_ and therefore it would be meaningless to talk of its precision as you might with a measurement.

In any case, in the incandescent bulbs that the OP is trying to emulate with LEDs, the filament _IS_ in a vacuum.

Reply to
pedant

And, talking of pedancy, the figure should have been quoted as 299792458.

And, don't start a sentence with a conjunction! :-)

(A preposition is not something that you should end a sentence with?)

Reply to
pedant

The OP is trying to emulate incandescent bulbs with LEDs because Railtrack is currently installing LEDs instead of incandescent bulbs in new and replacement signals. If they can get the right wavelength why can't the model manufacturers?

Reply to
Jane Sullivan

Network Rail (no longer "Railtrack") can get the right wavelength because their buying power (and huge budget) means that they can choose to buy whatever they want, almost regardless of cost.

Meanwhile, a small scale manufacturer of model railway signals needs to keep costs down, and probably has little choice other than to buy a commercially available LED with the closest match to the prototype in terms of colour.

Reply to
Bruce

In article , pedant writes

It is - but only in a vacuum.

Yes, but the velocity, and the wavelength, change when it leaves the vacuum and enters the space between the bulb and the viewer's eye. The frequency, of course, remains constant, as it must.

David

Reply to
David Littlewood

I suspect the regulations have changed to allow different wavelengths.

MBQ

Reply to
manatbandq

It's very difficult to create any arbitrary wavelength in LED. It's more likely that the regulations have changed or there is some filtering involved.

MBQ

Reply to
manatbandq

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