Lighting Trains

[cteno4]

Yeah it's the best design I've seen and actually is not all that hard to make. I like the idea of uplighting to a white painted ceiling or bit of construction paper to diffuse the light and run more leds at a lower current. Nice presentation as well!

 

Should work across all systems as well AFAICS.

 

Jeff

[Khaul]

I agree. THAT is a good video. I may start by using the LEDs and wires to build station lights before thinking about improving interior train lights.

[cteno4]

You can also adjust the led brightness on the current limiting chip by using a pot instead of a fixed resistor to set the current level.

 

Jeff

[kvp]

You can also adjust the led brightness on the current limiting chip by using a pot instead of a fixed resistor to set the current level.

Just never go below 7 ohms or you'll blow the chip and the leds. Also special low current leds are needed as the max. current from the chip is half of what is used by a standard led. He is using leds with 1:10th of current (1000% efficiency compared to normal ones).

[Khaul]

It looks like the Kato 11-211 board comes with both a rectifier and a current regulator. I think this blog entry, http://blog.goo.ne.jp/turn-table/e/4d067c695a3743590a05c8930c7a88d8, explains how to connect a small capacitor in parallel so the Kato interior lights work better with the Tomix CL system. I wonder whether a bigger capacitor soldered in the same place could be used to solve the flickering problem. The circuit would look very much like the one in Jeff's video, I think.

[cteno4]

Yep that should work. Some lighting boards come with small filtering caps but beefing up the cap just after the rectifier can help even out dropouts. You can also look at tantalum caps. These are usually in smd brick format for the polarized larger capacity caps and pack the best uf for size short of a micro super cap, but those are expensive and harder to source. There is a chap in thenus makingna really nice lighting board that uses small supercaps. The big electrolytic caps used in the video are a bit of overkill I think and could be replaced by a smaller 25v tantalum cap (or multiples as you can gang these up in parallel to give more capacitance.

 

http://www.ebay.com/itm/5Pcs-Tantalum-Capacitor-7343-25V-100Uf-Type-D-20-Surface-Mount-Smd-Ic-New-H-/252829585255?hash=item3addd14f67:g:Xv0AAOSwKOJYH46k

 

The two basic circuts are

 

Usual one in lighting boards and such and can change brightness with changing voltage

 

Track power - rectifier (fix polarization) - capicator (even out power) - resistor (drop current for led) - LED

 

 

The one in video uses a current regulating chip instead of a resistor to keep current to the led constant thru a wide voltage range unlike a fixed resistor where current to led will be affected by the track voltage

 

Track power - rectifier (fix polarization) - capicator (even out power) - current regulator (limits current for the leds) - resistor (wired to current limiting chip to set the fixed current leve of the chip) - LEDs

 

BTW I can't take credit for this video, Melandir found it a while back in a similar thread by costas. I just love the combo of what it does and their reasoning.

 

http://www.jnsforum.com/community/topic/8403-shinkansen-dcc-interior-lighting-with-flicker-free-feature/

 

Jeff

[kvp]

The big problem with the constant current source is that you need low current, high efficiency leds. Most cheap chinese leds or those found on self adhesive ribbons are the normal 10-20 mA types and not the 1-2 mA ones. You can see from the current consumption that the small current ones run around 10 times longer on the same capacitor charge, so the time gain is significant even with a simple resistor current limiter.

[cteno4]

Just never go below 7 ohms or you'll blow the chip and the leds. Also special low current leds are needed as the max. current from the chip is half of what is used by a standard led. He is using leds with 1:10th of current (1000% efficiency compared to normal ones).

Yep if a pot is used then a 10R smd resistor in series with a 100R smd pot will make sure you keep the minimum resistance for the current regulator chip.

 

http://www.ebay.com/itm/10x-SMD-Potentiometer-Trimmer-Variable-Resistor-4x4mm-100-ohm-100ohm-100R-101-/182375639703?hash=item2a766f6a97:g:2fkAAOSw4GVYQsr4

 

Jeff

[mrp]

I looked into this when I was adding caps to my own 11-211 lighting boards.  The "constant current chip" Kato are using is the Semitec S-183T 15mA CRD (Current Regulative Diode).  The board doesn't use any resistors at all - there's space for an 0805 SMD resistor but they just populate it with a zero-ohm link.

 

[cteno4]

Simpler with the CRD no setting resistor needed. Smaller too. Bit more expensive, like $2+. Lm334 chip is bigger, but adjustable and cheap at like 25 cents.

 

Jeff

[kvp]

The semitec chip is factory preset for the cheaper standard leds requiring between 10 to 20 mA. Much better if you use a single standard led. It could be added in place of normal resistors and just works.

Edited April 14, 2017 by kvp

[Khaul]

I have been experimenting today with the Kato 11-214 boards I got a few days ago. I've found out a few interesting things:

 

-the diagram from Sumida crossing posted in the previous page actually corresponds to the old board, which was reported to produce a lot more flickering.

-the copper stripes connect to the wheel pickups in both the front and the rear bogies. That should keep flickering under control over insulators and turnout frogs. Actually once I cleaned track and wheels I am getting pretty satisfactory results.

-the location of the clear plastic diffusor is extremely important to keep the car evenly lit. The diffusor should be located as close as possible to the LED. I have used cello tape to keep it in place, with a dramatic improvement.

 

I brought down the good camera and took a few pictures. It is hard to catch trains in movement with good light. See below:

 

Classic no lens vs lens photo

 

There is a chap at the controls, no more runaway trains. And well, the windscreen needs a good wash up.

 

Going artsy

 

 

Edited April 14, 2017 by Khaul

[cteno4]

There is a whole range of Semitic preprogrammed CRDs so you could choose what current you want to run the leds at. The 183 is for full led current 18ma (16-20 range).

 

It is super easy and simple, but at $2min not cheap.

 

Jeff

[gavino200]

 

-the copper stripes connect to the wheel pickups in both the front and the rear bogies. That should keep flickering under control over insulators and turnout frogs. Actually once I cleaned track and wheels I am getting pretty satisfactory results.

 

 

 

I'll have to open one of mine up to see if the copper pickups take current from both trucks. Do you recall if that's the stock situation, or did you connect them yourself?

 

BTW, that's a great result from the Kato kit. I don't think I ever got diffusion that even. Also nice touch with the train driver.

Edited April 14, 2017 by gavino200

[gavino200]

There is a whole range of Semitic preprogrammed CRDs so you could choose what current you want to run the leds at. The 183 is for full led current 18ma (16-20 range).

 

It is super easy and simple, but at $2min not cheap.

 

Jeff

 

I vaguely remember you (I think it was you, Jeff) talking about installing a magnetic switch into cars so that you can turn off the lights on trains that aren't in service. If that was you, did you make any progress with that?

[kvp]

For that, you need a bistable (aka. latching) reed switch which is polarity sensitive or a morse reed controlled bistable relay setup. Finding a small enough bistable reed is a big challange though. (the relay based circuit would be too big for N)

[gavino200]

For that, you need a bistable (aka. latching) reed switch which is polarity sensitive or a morse reed controlled bistable relay setup. Finding a small enough bistable reed is a big challange though. (the relay based circuit would be too big for N)

 

:(

 

I guess the only other option is a toggle switch to shut off the yards.

Edited April 14, 2017 by gavino200

[cteno4]

I have not done the reed switch for car lighting. i just saw an article on this and also a family friend when i was a kid had done this with latching reed switches switches to turn on and off lights on his big old marklin layout. with the latching reed switches you can just pass a magnet over them to turn them on/off, with your magic wand. but they are expensive, fragile, and rare beasties

 

http://www.trainelectronics.com/LED_Articles_2007/LED_103/index.htm

 

with regular non latching reed switches you could mount under cars with a bit of metal near it and just have a rare earth magnet you pop on to turn the cars on and pull off to turn them off (or the opposite with normally on reed switch). these guys are heartier and cheaper as its basically just two strips of metal that stick together only when the magnetic field is applied.

 

http://www.ebay.com/itm/10Pcs-14mm-Glass-Magnetic-Induction-Reed-Switch-MagSwitch-Normally-Open-NO-/192144773217?hash=item2cbcb89061:g:9ZsAAOSwmgJY3h6u

 

ive often wondered if these reed switches can get magnetized or bent and stuck over time with a magnet present.

 

putting in tiny toggle switches can be a PITA. but many of the small slide switches do look like undercarriage bits and so could hide there well, especially in the center. motor cars are harder as most of the undercarriage area is taken up by motor and drive shaft stuff. just mount the switch on the outside and drill a couple of tiny holes to run the switch pin and leads up into the subfloor or floor of the car. as you see this could get very fiddly to do.

 

http://www.ebay.com/itm/New-50Pcs-Slide-Switch-DPDT-6-Pin-Toggle-Switch-PCB-Panel-Mount-Mini-Micro-Hot-/152268772817?hash=item2373ed15d1:g:klwAAOSw6DtYRb6i

 

http://www.ebay.com/itm/50Pcs-MINI-SMD-Slide-Switch-1P2T-7Pin-for-DIY-Electronic-Accessories-/302264984486?hash=item466065a3a6:g:sb4AAOSwdIFXxWH~

 

jeff

[gavino200]

I have not done the reed switch for car lighting. i just saw an article on this and also a family friend when i was a kid had done this with latching reed switches switches to turn on and off lights on his big old marklin layout. with the latching reed switches you can just pass a magnet over them to turn them on/off, with your magic wand. but they are expensive, fragile, and rare beasties

 

http://www.trainelectronics.com/LED_Articles_2007/LED_103/index.htm

 

with regular non latching reed switches you could mount under cars with a bit of metal near it and just have a rare earth magnet you pop on to turn the cars on and pull off to turn them off (or the opposite with normally on reed switch). these guys are heartier and cheaper as its basically just two strips of metal that stick together only when the magnetic field is applied.

 

http://www.ebay.com/itm/10Pcs-14mm-Glass-Magnetic-Induction-Reed-Switch-MagSwitch-Normally-Open-NO-/192144773217?hash=item2cbcb89061:g:9ZsAAOSwmgJY3h6u

 

ive often wondered if these reed switches can get magnetized or bent and stuck over time with a magnet present.

 

putting in tiny toggle switches can be a PITA. but many of the small slide switches do look like undercarriage bits and so could hide there well, especially in the center. motor cars are harder as most of the undercarriage area is taken up by motor and drive shaft stuff. just mount the switch on the outside and drill a couple of tiny holes to run the switch pin and leads up into the subfloor or floor of the car. as you see this could get very fiddly to do.

 

http://www.ebay.com/itm/New-50Pcs-Slide-Switch-DPDT-6-Pin-Toggle-Switch-PCB-Panel-Mount-Mini-Micro-Hot-/152268772817?hash=item2373ed15d1:g:klwAAOSw6DtYRb6i

 

http://www.ebay.com/itm/50Pcs-MINI-SMD-Slide-Switch-1P2T-7Pin-for-DIY-Electronic-Accessories-/302264984486?hash=item466065a3a6:g:sb4AAOSwdIFXxWH~

 

jeff

 

Thanks for the info. The toggle switch I was talking about would be to kill the current to the yards, so that trains sitting inactive in the yards don't have all their car lights blaring. I'd just flip the switch when I want to use the yard.

[cteno4]

yep i was just following up on alternative to reed switch in each car. yard solution works well and simple! you could go the rich way and put a decoder in every car for lighting!  ;-p

 

jeff

[kvp]

The microswitch solution is actually supported by some manufacturers. For example some of my HG Tomix sets have them for turning off the headlights when coupled. The problem is you have to pick up the cars to change the settings.

 

For analog layouts, i would say cutting power in the yards is simple. But this won't allow turning off the lights when running in daylight (while keeping the headlihts on).

 

For DCC, you can add multiple decoders or wire the train to use a single bus. My Arnold Brighton Belle has this bus so a single decoder could control the motor, the two head/taillights and the internernal lights too. (even the table lamps) Coupling it up is painful though as the couplers are very fragile.

 

A cheap, durable and small bistable reed switch would be great. Or the digital alternative of using a reed sensor chip and a microcontroller. I'm talking about the same setup as in the Tomytec buses, but with CL track power and internal non volatile memory to remember the state through power loss. Though this would cost slightly more than a DCC light decoder that supports analog mode.

[gavino200]

yep i was just following up on alternative to reed switch in each car. yard solution works well and simple! you could go the rich way and put a decoder in every car for lighting!  ;-p

 

jeff

 

Yes, when I get to the point where there's absolutely no other train related desire competing for my dollars, I might do that. 

[gavino200]

Just out of curiosity, what would be the absolute cheapest decoder that would work?

[kvp]

Something from Digitrax. Like the Kato light decoders or the wired variants sold with their own brandname.

[Khaul]

I'll have to open one of mine up to see if the copper pickups take current from both trucks. Do you recall if that's the stock situation, or did you connect them yourself?

 

BTW, that's a great result from the Kato kit. I don't think I ever got diffusion that even. Also nice touch with the train driver.

 

That's stock, at least in my two sets. You don't need to open anything, just take a non-motor car and test one bogie at a time in energised track :)