Shinkansen DCC Interior lighting with Flicker-Free feature

[cteno4]

ah yes on closer inspection the strip lights that zebbu showed do look to be all in parallel as there appears to be a resistor for every led.

 

jeff

[Melandir]

ah yes on closer inspection the strip lights that zebbu showed do look to be all in parallel as there appears to be a resistor for every led.

 

jeff

 

Corret but if you look even closer you could see that his leds were RGB leds so basically 3 leds in one package, the strip he used have 4 pins, 1 common and 1 for each color marked RGB

[lurkingknight]

if he used the 5050 strips rather than 3528s it could account for the extra brightness even before adding resistors. the 5050 led is a lot brighter than the 3528.

[Melandir]

Costas

 

thanks to your information I was able to put some light on my Tokyo metro train, due to no space in the undercarriage like in a shinkansen train, I used the space Kato reserved for his light kit and it looks like a perfect fit

 

I used a 3.9 Kohm resistor to reduce the light emitted

Edited March 18, 2014 by Melandir

[Costas]

Glad you found the thread helpful... One thing I will add is that you may wish to try and find some thinner wire - something around 30AWG size as this can make it a lot easier to install in tight spaces.

 

Let us know how you find its performance as far as anti-flickering is concerned.

[Melandir]

Glad you found the thread helpful... One thing I will add is that you may wish to try and find some thinner wire - something around 30AWG size as this can make it a lot easier to install in tight spaces.

 

Let us know how you find its performance as far as anti-flickering is concerned.

 

I have used the 24AWG solid copper and they are a bit tought to work with,

I'll try to find some 30AWG solid copper

 

thanks again

[kvp]

My suggestion would be wires from ethernet or phone cables. They are really thin, but can carry just enough current (see: power over ethernet). Although solid copper is easier to bend into a specific shape and can hold smaller circuits in place.

[Melandir]

I'll test both in my next train, but I think that 30awg solid Cooper should be the best compromise between flexibility and power capacity, and the fact that could hold small circuits it's a plus I like

[Lawrence]

My suggestion would be wires from ethernet or phone cables. They are really thin, but can carry just enough current (see: power over ethernet). Although solid copper is easier to bend into a specific shape and can hold smaller circuits in place.

 

I had a locomotive motor which had a broken commutator so I stripped it down and using the wire from the armature windings, they have a thin enamel coating on them but that can be burned off with the soldering iron.  I found the ethernet or phone cables too brittle, armature cable is more flexible and will take a little more punishment

[kvp]

 

I found the ethernet or phone cables too brittle

I think we are talking about different cables. I meant the cables that are used to connect the various devices to the wall sockets. They are meant to be swung around, stepped on, etc., so if they are tough enough to survive that, they should be tough enough for a small circuit. On the other hand, most armature wires snap very easily. You can lift a desk phone by it's cable, but i think you can't really do the same with the thin armature wire used in small models. However both were used for decoder installations so both should work, but lately the plastic covered colored wire seems to be more common.

[Melandir]

Looking around I have found another way for a light system flicker free in DCC

I'm now ordering the material and will let you know if this could be used inside our models

 

Edited December 29, 2014 by Melandir

[cteno4]

Melanir,

 

Hey great video! Thanks mucho for finding it and posting! Creators went to a lot of effort to do a nice job on the circuit and on the presentation!

 

I just happen to have all those components sitting here! I've been collecting bits to experiment with to make a constant lighting circuit like this going with more LEDs and low amperage like this. I've found in all my playing with led lighting in cars and structures that going with more at low amps gives a much better effect than a few mini suns at full amps! The current limiting diode looked interesting as well, but hard to source cheap here in the states. The lm334 is bit less than a dollar here so not bad. Tantalum cap could reduce the space but will drive the cost up. With regular dc you are stuck with the 5v start voltage. If you eliminate the rectifier and go with resistor current limiting then when you protect the led at full 12v it's a bit dim at 3v or so and then loose the constant brightness feature. Would be great to build in a dc-doc voltage up feature to start lower, but then there would have to be a limiter as well and gets complex fast (perhaps this will start kvp's gears churning!)

 

My plan was to wire up a few different options and play with them with different motors to see the effects.

 

Would be great to have a tomix style high freq lighting power source that could be added to regular dc power packs. That would eliminate the high start voltage and keep the lights on all the time. Kvp had mentioned he has built an add on like this using pics.

 

The up lighting onto the white paper is also brilliant! The thought had crossed my mind a few times, but to my embarrassment I've never put it down on the list of things to fiddle with! Challenge will be to see if that will work in japanese car heights.

 

The last concept of doing colored interior details is also so true and neglected. Just painting the floors and seats will create a much more realistic reflected picture to the eye than the monocolored glow you will get from a unicolored interior. When we use to shoot exhibit models we use to use a kookalorus (basically a mobile with different shaped bits of paper on it) with different colors to give more random colored reflected lighting to break up the intense direct lighting. With a better mixed colored picture you don't have to have the car so unrealistically lit up so that its lighting the 50' of scenery to either side of the track!

 

Cheers

 

Jeff

[kvp]

 

Would be great to have a tomix style high freq lighting power source that could be added to regular dc power packs. That would eliminate the high start voltage and keep the lights on all the time. Kvp had mentioned he has built an add on like this using pics.

Actually i've built a whole mini Tomix style power pack, that takes 12V DC and outputs variable PWM. This means that on low settings, the train won't move, but all the interior lights and directional headlights will light up. The frequency can be high as a few kHz or as low as 50 or 100 Hz, if you want to use really old motors that don't like high frequencies or want to be safe for DCC decoders used in analog mode. The trick is that during the brief PWM cycle the capacitors get charged and the resistor bridge keeps them discharging through the motor, but the motor doesn't get enough power to start moving. This allows stopped trains to stay lit.

 

The extra neat tricks in the video are the constant current source, the specially matched turn on voltage leds (unmatched ones wouldn't light up evenly without extra resistors) and the reflective lighting, which works in any car where there is enough space above the window line. One extra remark though, the 10 mA current limit is for all leds, so you need matched low current leds, so they can divide the current amongst them. Without that, only the lowest turn on voltage led would turn on. Also low current means they have the required brightness after dividing the maximal 10 mA by the number of the leds connected in parallel. Most normal leds require 10-20 mA by themselves.

[Melandir]

I used costas system up until now to light up my trains

I have now ordered all the required material for thid new system, the most expensive piece were the 0.5mm (24awg) brass rod and the high powered led,

I have bought normal power ones so I expect to use one more than the 6 reccomended 

 

I have currently a serie 500 shinkansen and the kato twilight express (will be released in January) to light up so I can eperiment with two different carriage types

 

Because they take the biggest space I have bought 3 types of cap to test

100uF 25V tantalum, 220uF 25V electro, 220uF 25V aluminium smd

 

I'll update this topic once I receive the material from China and will start assembly it

[cteno4]

Melandir,

 

Great will love to see what you do! I hope to get the time soon to get back on this. Also will be interested to see how it works in the cramped space in a 500. At least rarely you look directly into the windows from the side, usually it's from above we view the trains.

 

I was amazed how long the LEDs stayed lit with the 220uf cap, plenty for dirty track.

 

Also see if you can source piano or music wire in your area as that can be much cheaper than brass rod from the hobby shop.

 

Cheers

 

Jeff

[HantuBlauLOL]

I'm interested to try the method from the video.. Could it be used on motor and cab cars mounted with bulbs? I'm afraid of burning them..

[kvp]

You can use it parallel with bulbs, but this means you have to separate the two circuits at the pickups. The bulbs will flicker, but the led lights will stay lit. The trick is that the diode bridge rectifier has a side effect that the buffer capacitor can not be discharged by a motor or a bulb light. You can't power a bulb light from this buffer circuit. Also the circuit can't drive bidirectional led lights either. For unidirectional (single color only) lights, it can be used, but you have to change the diode bridge into a half wave rectifier, so it gets charged only in one direction (polarity) only.

 

ps: I would replace the bulbs with led + resistor combos, just watch out for the correct polarity. For a non directional bulb (one without a diode) you can either add a diode or two leds back to back before the series resistor, so one of them will always light up regardless of direction.

[kvp]

I've attached the circuit from the video: (copyright by the owner of the video)

 

 

You can use it parallel with bulbs, but this means you have to separate the two circuits at the pickups. The bulbs will flicker, but the led lights will stay lit. The trick is that the diode bridge rectifier has a side effect that the buffer capacitor can not be discharged by a motor or a bulb light. You can't power a bulb light from this buffer circuit. Also the circuit can't drive bidirectional led lights either. For unidirectional (single color only) lights, it can be used, but you have to change the diode bridge into a half wave rectifier, so it gets charged only in one direction (polarity) only.

 

ps: I would replace the bulbs with led + resistor combos, just watch out for the correct polarity. For a non directional bulb (one without a diode) you can either add a diode or two leds back to back before the series resistor, so one of them will always light up regardless of direction.

[HantuBlauLOL]

So I need to place the motor and/or the bulbs outside that circuit?

[kvp]

So I need to place the motor and/or the bulbs outside that circuit?

 

Yes! Neither of them can run on 10 mA and they would just short out the capacitor.

 

 Sadly even bidirectional (bipolar) led headlights won't work with this circuit, so if you want to use it with two color headlights, you have to modify them to be separate circuits like you would do when adding a conventional DCC decoder and then you would need two half bridge rectifiers and two circuits to drive them and a third with the full bridge above for the internal lights. That's 3 large capacitors per end car to place somewhere...

[HantuBlauLOL]

Oh well.. Btw can i place another capacitor (probably tantalum, because of limited space) outside of that circuit? I mean parallel to the motor, cab light, and the interior light circuit, just like what this thread poster did

[kvp]

Of course. Some cab cars already have one for the head/tail lights. Just be sure to choose one that is AC tolerant (doesn't have a polarity) and have a high enough voltage rating to be safe in case of motor backemf voltage spikes. (usually maximal track voltage x 1.5 is enough, in this case 16V * 1.5 = 24V; the poster of the video choose 25V to be safe)

[HantuBlauLOL]

So I would need a 18V AC cap for max 12V input? Is it safe to be used on less than 12V input?

[kvp]

Yes, but most controllers can output more. The Kato one for example can produce 16V in the red. The caps can be used on less, but not more. You can literally blow your shell to pieces with a blown cap. I would say you should use a 24-25V cap for N scale to be sure. Actually this is the NMRA recommendation too. :-)

[HantuBlauLOL]

Finally bought the 25V.. Was afraid of the BOOM of a bomb-o-citor with exceeding the max voltage limit lol

 

Seriously, I saw some on YouTube.