Lighting up the Lady Diana Spencer Class 47 Diesel from the 80's

[Augustus Caesar]

From the title of this thread you will see what I am trying to do... simply place some LEDs into the Class 47 712 Lady Diana Spencer, pictured, hopefully, below...

 

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As you can see there are two headlamps (the reverse of which on this model has the old IV03 numbering headcode) and two tail lights (yes, I know - there's two each at the other end... lol) and I do have very small LEDs to fit. While there is no central headlight on this loco would you say I would be better and more accurate with warm white, white or yellow LEDs? I would think that 3mm ones would be way too big and white too bright(?). I've read that yellow would be more accurate for the period. This model was released in 1981 and I absolutely love it. It still runs fabulously well and is surprisingly quiet for a three pole motor.

Anway... I will probably use 1.8mm red and will await the colour before suing a particular size.

I am not looking for any help with wiring to a decoder of any type as I already know how to do this... the question is purely about the subject mentioned above.

Any help apprecated guys...

[Augustus Caesar]

I posted this a good few days before it was listed as the post contained a pic... well, it doesn't seem to be showing. No worries.

More importantly has anyone got any ideas on what I should use to have this loco use LEDs? Any Class 47 of this ilk can be offered as an example guys... so... anyone? Come on fellas... you can't ALL be on holiday!!!! :-)

[NormanQ4]

I've just fitted warm white to the interior of carriages which is probably a close as you'll get to incandescent which would represent the steam period.

Warm white has a slight yellow tinge.

A friend fitted white and they are very bright which is like the colour you would get from fluorescent or halogen lights which would represent the 80s.

I would say white, definitely not yellow.

[Augustus Caesar]

I've just fitted warm white to the interior of carriages which is probably a close as you'll get to incandescent which would represent the steam period.

Warm white has a slight yellow tinge.

A friend fitted white and they are very bright which is like the colour you would get from fluorescent or halogen lights which would represent the 80s.

I would say white, definitely not yellow.

Thanks for that Norman...

White does seem to be a better choice but as this loco is diesel I am pretty convinced I did read somewhere on another forum a good while back that the warm white would be best for this type of loco. From what I can remember (I can't find that thread now) that same post stated that engines of this type did give off a yellowish hint. I ask on here because I am not so sure of myself when trying to remember what was actually stated back then.

I think I would prefer accuracy for this loco I am fitting LED's to because it is such a prized possession. If it were another Class 47 it would have been different maybe.

The other reason I ask is that I have not spotted a Class 47 at a show with LED's either inside or on. Maybe I haven't been paying attention!!

Thanks again and I will remember what you say when deciding.

[Augustus Caesar]

 http://sulzerpower.com/news.html

does this help

i would try warm white in a yellow lens,mixing a led lamp with different lens covers can make some interesting tones

Thanks magfan... some useful pics etc on that site although it is a little hard to navigate around until you get used to it!

It also led me to a video on the Tube showing this loco in its brand new Scotrail livery passing through Carlisle pulled by a Class 57 ready for intro to its new service.

One question... you have intrigued me by mentioned warm white in a yellow lens. I've not heard of lenses being used on LED's as this particular area is still newish to me. Can you explain what these lens covers are and how I research them for example? I take it they sit on the LED tip? Or am I incorrect in that assumption?

[Augustus Caesar]

Ah... a picture showing the lights on. Even better. Sort of makes my mind up now then. I've checked that link out magfan so thanks for that one. Some fantastic photo's on there.

Would anyone be able to confirm whether these lights are yellow, warm white or even amber? If not I will get different ones and experiment before fitting.

Thanks again magfan... great stuff!!

[Augustus Caesar]

Found some on the recommended search magfan, thanks. Didn't realise these things were available.

Doesn't a resistor dim down the light when putting one resistor to two LED's on the same circuit though? If the colour is not right and not available then these may be useful.

I do have a couple of sapphire decoders which I can remove from one of the other loco's if necesary too. So at least I have three options now whereas before I didn't really have much of a clue regards lights on the 47's of the early eighties era.

I'll pick up a few LED's and see how they look and if I need the caps then I will consider them.

Thanks again magfan... :-)

[PJR_slo]

Hi AC

 

Resistors are simply to limit the current draw of an LED.  If you take a warm white LED (which is what I would recommend for this installation), the Vf (forward voltage) will be around 3V.  Most LEDs of this style will work up to a maximum of 20mA.

 

Assuming that the supply voltage is 14V, then you will need to drop 11V across the resistor, so the smallest value resistor you should use will be about 11/0.02 = 550 Ohms (560 Ohms being the closest ABOVE).

 

That would give full brightness on a single LED.  If you wire 2 LEDs in series with the resistor, then you will require 8/.02 = 400 Ohm.  To reduce the current (brightness), you can either increase the resistor value (up to a point where the LED will not work) or feed it via a PWM output - but only certain decoders can do this.

 

I think you will find that a 1kOhm resistor with a single LED or 820Ohm with 2 LEDs in series will do what you require.  If that's not bright enough, then try 820/680 Ohm resistors.

 

The advantage of wiring 2 LEDs in series is that you use less current than 2 in parallel.  The disadvantage is that both LEDs need to be quite closely matched otherwise one will appear a lot brighter than the other.

 

Hope this helps.

 

Peter

[PJR_slo]

AC

 

Note that if you choose to vary the brightness of a LED with the decoder, then you will still require a resistor of the appropriate value for limiting the current to a maximum of 20mA.

 

Personally I am not a huge fan of Hornby decoders; I prefer Zimo, although I do have a few Sapphires for testing.  I have blown up a few Sapphires, whereas both Zimo and ESU seem to be better protected in this regard.

 

Peter

[Augustus Caesar]

@Peter

I wired up a friend's Rapier last year and used 1 white LED per 1k resistor and also a Hornby 4 function decoder to boot. Obviously red LED's were used too and again 1 resistor per LED. This gave directional lighting and worked very well. However the white was too strong for me but my friend loved it!

So you recommend warm white? Why not the yellow as some others elsewhere seem to use? I will be using the lighthouse type LED for both the white and red and sizes will be 1.8mm for red and 2mm for white/warm white. The supply will come from the eLink unit and RM will work from my laptop and a hand held tablet running Windows (the version is unimportant for now). I say 2mm for the white/warm white because to me 3mm seems too broad and way too bright from what I have seen on the Tube etc.

Why do you prefer Zimo over Hornby?

 

@magfan

I will be using the Sapphire decoder here as it offers fuel and water level settings (which seems fun - well, at least for a while!) and also other functions that will make using this decoder worthwhile on this project and my layout. I also like the idea that the LED's can be dimmed if too bright so a winner all through for me thus far.

 

Once again thanks guys. All help is very much appreciated as always. One has a high knowledge base when computers are concerned but some rail matters are a little less forthcoming to me. I learn quickly though! :-)

[PJR_slo]

AC

 

I think you will find the yellow too yellow.  The warm while is more yellow the dimmer it gets.  The forward voltage for red LEDs is only around 2V, so you have to adjust accordingly.  

 

I would suggest that you try 820Ω resistors with 2 white LEDs in series to start with and see how that goes.  The red LEDs will probably be OK for you with a 1kΩ resistor and 2 LEDs in series (doing the math, that's about 10mA each pair for both red and white, but the red will probably be slightly less bright).  That's not a lot of current drain from the eLink!

 

Most of the smaller LEDs run at about 20mA max, but they can very in brightness quite considerably.  I tend to use 3mm LEDs a lot with brightness between 3000mcd and 13000 mcd depending on colour (white around 13000 and red/yellow around 8000).

 

The brightness, current and forward voltage should be specified by the seller.  I would tend to stay clear of sellers not giving this information.

 

I get my LEDs from eBay (supplier: bright_components) - I buy in packs of 50 for around £2.50.  He also sells all the resistors.

 

It's probably well worth buying a selection of LEDs, hooking them up to a 12V supply (with the resistors) and seeing what you like best.  I think that any video recording will accentuate the brightness and change the colour of LEDs somewhat.

 

Why Zimo? Well for a start I have never had one break.  Or lose its settings.  They have auto-reset thermal protection which protects all outputs.  I find them more flexible than ESU and the manual is easier to follow and I find changing CVs easier than with ESU.  The Zimo decoders will also drive Seuthe smoke generators directly (unlike any of Hornby's decoders).  Also I only buy sound decoders and Hornby don't sell sound decoders.

 

I have not bought any TTS locos simply because of the low specification of the function outputs.  I tinker a lot; I make many mistakes.  I don't want to be buying new decoders at £80 each whenever I make a mistake!

 

Have fun!

 

Peter

[poliss]

 Have you seen the guides on the duxfordupdate website? Here's one page that deals with LEDS.

http://s374444733.websitehome.co.uk/led-guide/index.htm 

He has added lights to quite a few locos as can be seen elsewhere on his site.

[Augustus Caesar]

@poliss

That is one link I had a while ago and lost when I reinstalled Windows after an update failure and forgot to save out the Bookmarks on Firefox! I'm pleased you pointed this one out as now I can return it to where it belongs. Thanks for that... :-)

 

@Peter

You've given a lot of food for thought and I will probably go warm white and maybe put them in series. I have a bread board which I can test using a 9V battery until I get a more substantial 12V supply which will easy enough.

A set of resistors with different values seems a good idea so testing can be done with a little more accuracy before wiring up to find they don't suit. I'll check your supplier too and may even consider trying a Zimo decoder later on when I have a loco to fit one to or when I can get round to removing Hornby decoders from current stock.

You're right when talking about video altering the light levels... red LED's fail to photograph very well at the best of times and can show as white with a red outer glow! A quirk of photography and not the LED.

 

Great input again guys... thanks. :-)