Modifications to Easy Peasy Passenger Car Lighting

[mmagliaro]

So we're talking voltage regulator, capacitor and two resistors to convert the unit to run off DCC, correct?  And all of those components can fit on the board where the batteries currently are.

Also, isn't Kato's lighting kit designed for DCC with evenly distributed lighting from golden white LEDs?  The Kato units easily can be adapted for other models.  MSRP is $10 for the Kato (in the six-pack) versus $9 for the EPs.  Seems that for $1 more ($0.70 more at the online sites), I don't have to worry about changing batteries frequently.  It's also easy to swap in Kato trucks on various passenger models, which simplifies the current pick-up.

Right.  But you have to clean wheels,  buy Kato trucks for cars that don't have them (even if they are the wrong style
of trucks), solder wires or make a contact scheme to touch the Kato truck tangs inside the car, and solder in a regulator
circuit if you want the light to be constant (and it still won't be on a DC system until the track power is up to about 4 volts).

None of that is "bad".
We are just  talking about two different goals and two different product types.
I could certainly make or buy a track pickup circuit and make that work.  I've done it before.

Easy Peasy boards meet a different need.

Perhaps for you (or me), the devil is in the word "frequently".   If I get battery life up to where I don't have to worry about changing
batteries for a year, is that a fair exchange when I can drop these into any of 4 brands of car I own with ease and get
steady, trouble-free  light?  No truck changing.  No internal wiring.    It is to me.   If I owned 20 or 30 (or 100)  passenger cars
and ran them all the time, I might feel differently.  But I don't.   

I will restate, my goal here was to investigate ways to improve the Easy Peasy boards, not engage in a debate about
whether track power or battery power is better. 

[peteski]

As Brian mentioned, all the current Kato lighting boards (the ones that use LEDs) are designed to run on DC and DCC without modifications.  They use cool white LEDs (similar in color to fluorescent light) and they also include amber filter to be installed over the LED if one desires a warmer color.

To me, even if I only had couple of passenger cars, it would still make more sense to use those than lighting circuit using small watch batteries and which has to be manually turned off when I'm done running the models.

Personally, I haven't experienced too much flicker when using Kato lighting boards, but I have designed a circuit which eliminates the flicker. It consists of one resistor and one capacitor. Simple modification of the Kato's circuit board is required.

As far as your quest to have longer battery life, there is only so much capacity you can pack in a small package.  Lithium batteries seem to have the highest energy density per cubic inch.  You could replace the stock batteries with larger lithium batteries. But they will also be physically larger than the stock batteries, so you'll have to find some place to hide them. Two 3V batteries will provide 6V. You will have to modify the rest of that circuit (change or add a resistor maybe) to work on 6V. Other than that, there are no miracle mega-capacity micro-batteries.   

[bbussey]

... I will restate, my goal here was to investigate ways to improve the Easy Peasy boards, not engage in a debate about whether track power or battery power is better.

Understood.  I'm just having trouble understanding what the advantage is.  You're still moving and re-soldering components, and Kato does offer a variety of trucks that covers most of the common types.

[mmagliaro]

Understood.  I'm just having trouble understanding what the advantage is.  You're still moving and re-soldering components, and Kato does offer a variety of trucks that covers most of the common types.

Ah, okay.  Fair enough.
Bear in mind that I have a set of track-powere Kato cars (the older style with the incandescents in them), and  years ago
I made my own lighted caboose circuit with track pickups and a circuit to recharge a small rechargeable button cell inside the car.

In other words, I've used and own track-powered cars for a long time, and if I wanted to, I could have added circuitry to my Kato
set to get rid of flicker and keep the brightness constant.

But... now I have this mix of some Con-Cor, some Rapido, some Kato custom-painted, some Walthers cars in an NP set, and
I have some SP&S custom MTL cars.   When I consider how often I actually use the car lighting, how easy the boards are to install,
how much light I get out of them, and so on,  the Rapido lighting wins over all my other options.   The moving and resoldering I have done in this experiment is pretty minimal.    Some of you folks hate the batteries.  I get it.  But I use them for short periods, so if
I could get some more run-time out of them, I'd have a simple drop-in solution that would look good to me, be easier than
anything else, and require battery changes very infrequently.

Peteski, you're right,  there's no miracle super battery.  But as I'm pointing out in here, there are some clear options that Rapido overlooked.
The SR45 battery can fit into the exact same location on the board, as I've shown, and provide at least 50% more battery life.
Even more important, the SR series silver oxides have a flat discharge curve, so the cars will stay at near full brightness
right up until when the batteries quit as opposed to gradually dimming and dimming over time, while the hapless observer (me in this
case) thinks they are still working, but somehow just don't look as good as they used to.


Just hang on a few days, guys.  I have some SR45's and SR41's coming in the mail (not questionable ones in a lot of 500 from China, either).  So I am going to just run 4 boards head-to-head with the 4 options, and see what really holds up and for how long.

Now.... speaking of simple fixes...
Does anybody have an idea on how one might apply a clear paint or stain to the Rapido green-tinted LEDs, to make them warm up and
lose their greenish hue?  Perhaps a tinted sleeve?   

[ljudice]

Bulb paint is found at auto parts stores....   

Perhaps amber or red would do something, though I don't know what....

[SkipGear]

If you want to try tinting the existing LED, pick up some Tamiya clear colors. They have yellow, amber, red, green, and blue.

[Zox]

Does anybody have an idea on how one might apply a clear paint or stain to the Rapido green-tinted LEDs, to make them warm up and
lose their greenish hue?  Perhaps a tinted sleeve?

Just as an experiment, I'd try sanding/filing the existing "green-tinted" LEDs, to see if it's already a coating applied to an otherwise-white LED. Generally if LEDs aren't some variant of white, they're exceedingly colorful, not just "tinted."

[peteski]

Max,
Too bad that I don't have one of those units to examine the LED, but maybe I can give a more generic answer.

All the LEDs, except for white, only emit a narrow color spectrum which peaks at the color they are designed to emit. To  say it another way, a green LED emits light only in the green range.  It does not emit any red or blue light.  A white LED (which is usually a blue LED with a special phosphor coating the blue LED die) emits a broader spectrum of color. Some of the blue light gets pass the phosphor. It also excites the phosphor causing it to emit a broad spectrum of colors (from green through reds). The blend of colors emitted by such LEDs appears white to the human eye.

If the source of light emits a broad range of colors such as a white LED or incandescent bulb, a transparent filter can be used to change its color. To get green light, a green filter will partially block all the colors, except for green.  Changing the color fo the filter will change the color of the light from a broad-spectrum light sources.

But using a filter which is of different color that the light emitted by a standard (narrow spectrum) LED will not result in drastic color change. Trying to get yellow light from a green LED will not work. At best, if the LED is emitting some light in the yellow color range, it will be very dim (as the majority of its light output is in the green range).

SO, whether you can filter the green light depends on what type of LED is used in that circuit. If they use a phosphor-based white LED, and if the LED case is tinted green, then you might be able to thin the case to allow more of the other colors to be passed through.  But if the LED is a simple green LED then there is nothing you can do (other than replacing the LED) to change its color.

[DKS]

SO, whether you can filter the green light depends on what type of LED is used in that circuit. If they use a phosphor-based white LED, and if the LED case is tinted green, then you might be able to thin the case to allow more of the other colors to be passed through.  But if the LED is a simple green LED then there is nothing you can do (other than replacing the LED) to change its color.

I have yet to see a colored LED that consists of a white LED with a colored filter. And I have many hundreds of them. LEDs that generate a color, as Peteski says, emit just that color, regardless of the color of the LED package. A green LED will be green whether the package is green, whitish or clear. Colored LEDs can be made to a very specific frequency; currently there are dozens of different shades of green alone. It's also possible to special-order LEDs to a precise color match. But because these LEDs emit a very specific color, you won't be able to alter its appearance with filters. Now, you can take a white LED and place it behind a filter to make your own particular color, and this may be the only way to get some exotic color that's outside the realm of those that can be generated, especially if the color is not "pure" (i.e., it consists of a mixture of multiple hues). But as Peteski says, if you want, say, a different shade of green in an existing device, you'l likely have to replace the LED.

[mmagliaro]

Yep, guys, you are absolutely right.  I just wasn't thinking.  Color LEDs even usually have the wavelength of their
light listed in the data sheet for them.   A green LED isn't going to put out anything but green.  It was just a thought.
I can unsolder and replace them easily, but I was thinking about an easier solution for other people who many not want to
solder.

[mmagliaro]

Here is a series of photos showing a head-to-head test of 3 battery types in stock Easy Peasy
boards.

We have
LR41 (alkaline, these are the stock type that are shipped with the car)
SR41 (silver oxide, exactly the same size, fit right in, but are expected to provide longer life)
SR45 (silver oxide, a larger diameter battery which can be made to fit into the existing holders
with a little solder-loosening and rebending of the holders)

As I expected, the SR41 and 45 lasted a lot longer than the LR41.  What surprised me
is that the SR45 really did not last any longer than the SR41, even though its mAh rating is a good 50%
higher.

I judged the life based on how bright the LEDs seem to hold up.  I admit, this is a little subjective,
so you can judge for yourself from the series of photos.

LR41  about 22 hrs
SR41 and SR45  about 32 hrs

Still to come, a head-to-head using the replacement golden white LEDs, which use quite a bit
less current, even with no brightness-reducing resistor, on these boards.

So, for somebody who uses them maybe an hour a week, you need a batter change about
every 8 months (vs 5-1/2 months with the stock battery).   If you run them at a train show
for 8 hrs a day, they'll be dead in 2-3 days.   I suppose their convenience, steady light, and
immunity to dirty wheels is enough of a pay-off depending on how much you use them.

Times are noted as hh:mm, the total hours and minutes of run-time.

00:00


03:00


07:30


11:30


11:30 (night view)


19:30


24:30  At this point, I call the LR41 "dead" because the light output has dropped off so much.
Giving it the benefit of the doubt, since I don't know exactly where between 19:30 and 24:30 it dropped
off, I'll call it 22:00.


28:30 (LR41 is now totally dead)


28:30 night view


34:00   
This is a little subjective, but at 34 hrs, even though these are putting out some usable light,
I think it has faded enough that I would be changing the batteries, I'll call it 32 hrs.