LED Flickering Firebox Board

That's very cool and thanks for sharing. I would love to see a video of this is action!

Man, one idea after another comes out of the JW & Assoc. R&D department. I'm in for a 6 pack when you get the boards made. All of the parts are OTC and easily acquired. Quick question, can I use the same 5V tap off of the R2LC in conjunction with the chuff generator?

Sooooooo John, how long before you come out with your own command system.

Well, the command system is way off in the future, so far that I can't even see it!   I suspect you'd need a separate supply, the R2LC can't supply enough juice to run more than a very small low current device.

I've done a few of these, but they're all hand-built, I'm thinking I'd like to make it easier to slap them together.

I did toy with the idea of adding a choke, rectifier and filter cap to make this a track-powered unit. but that might increase the size too much.  I suppose I could make those components optional.  I do have this little module that supplies 5V to run stuff like this.

Another great product. I like this tiny stuff...

Love the idea john

GRJ added the flickering firebox in one of the upgrades he did for me.   It's very cool!   Great idea

If size matters (grinding down a 3mm flickering LED), you might try a microcontroller driving thin surface-mount LEDs.  I know those flickering LEDs are inexpensive...but an 8-pin surface-mount microcontroller is less than 50 cents and could drive 4 generic surface-mount LEDs (a few pennies each) in a flickering pattern.  Here's an example of a small, thin PCB with an 8-pin microcontroller and 3 size 0603 (0.06" x 0.03") orange LEDs.  The microcontroller has a simple program generating "random" numbers to flicker the 3 independent LEDs.

In the above case, the flickering was to simulate 50 cal machine gun "flicker" on a 1/48 scale P-51.  An 8-pin microcontroller as shown could drive 4 surface-mount LEDs of course; actually I made such a board to drive 4 flickering LEDs to simulate the 4 nose guns of a P-38 Lightning but can't find the photos.  Obviously the colors of the LEDs could be mixed for your multi-color firebox.

Once you have a 50 cent microcontroller chip performing the "flickering" all kinds of opportunities come into play.  Here's another tiny surface-mount PCB with a larger microcontroller driving 12 surface-mount size 0603 LEDs - 6 orange, 6 blue.  This is simulating the exhaust flicker/flames of a P-51 Merlin 12-port engine, 6 exhaust stacks per side, in a 1/48 scale model.

In addition to "flickering" the LEDs, the microcontroller chip can control the ratio of orange and blue LEDs to simulate fuel mix adjustment or cleaner "blue" burn.  Again, this is a very thin assembly using all surface mount components and 0603 surface-mount LEDs.

In the case of firebox flicker, I wonder if the "average" color of the glow shifted with power or time.  There's that corny MTH steam engine cab chatter, "Those black diamonds are red hot!"

And here they are in action.  I dug these photos/videos out from a while back so the quality is a bit lacking.

That's "over the top" Stan, very cool simulations. Very realistic effects, I think we see where you spent some of your time.

I think I'll stick with the KISS principle this time, but it's food for thought.

FWIW, I actually grind them down to eliminate the point of light effect of the front lens, they look better with the light diffused from the flickering element.  It doesn't hurt that it helps the clearance a bit, but that's a secondary benefit.

OK, so maybe not on your Challenger, but in the "food for thought" department, using surface-mount LEDs instead of 3mm through-hole LEDs would make it easy to mount a SOIC-8 microcontroller on the back of the board. 

In my opinion you could then drive 4 LEDs using only 1 current limiting resistor (rather than 1 each per LED).  So add C1 for the uC and that would be all the components on the back...and 4 (or more) surface-mount LEDs on the front.

Looking at it a different way, suppose I told you there was an SOIC-8 chip that operated on 5V and had 4 flickering outputs and cost 50 cents (or whatever).  Now suppose that same SOIC-8 chip had a control pin that could select the output format from 4 flickering to 4 chasing sequence LEDs...in other words 1-2-3-4-1-2-3-4-etc.  This could be used as a basis for a more realistic rotating beacon simulation on a diesel.  Then suppose you could select the output format to drive LEDs in a Gyralite/Mars pattern.  And so on.

Here's a 1/48 scale rotating beacon in action.  "Behind the curtain" is a small PCB similar to one shown above with 4 surface-mount red LEDs (and some fiber-optics).

Stan, I certainly don't reject the idea, it's certainly capable of making a more low profile package, which is always a good thing.  I was thinking of the chips I got that are the multi-color LED's in a single SMT package.  I could probably mount that on one side and have the uP vary the colors between red and yellow randomly, that might be a pretty nice firebox effect.  I could even toss in a tiny hint of green and blue occasionally to spice things up.  I haven't tried that, but it's an interesting idea.  Since those chips less than 1/4" square, I could mount two side by side.  An 8 pin uP would neatly drive both of them with separate outputs for each color of each chip.

The opening in a few fireboxes that I measured was 1/4" high by a bit less than 1/2" wide and rounded corners.

My other issue with the small SMT LED's is they're somewhat of a PITA to hand solder, especially if you try to pack them in.  For my Chuff-Generator, the little 0603 LED was probably the most difficult component to handle, and they also are easy to overheat and kill them.  For stuff like this that I doubt that will ever get mass produced, I try to stick with easy to build layouts and parts.  I don't always totally succeed, but I do try.

Interesting you bring up those RGB surface-mount LEDs. 

I think of the flickering LED or the blinking LED as something you only find in 3mm/5mm thru-hole LEDs.  Even the thru-hole RGB LEDs come in versions which automatically change through the colors of the rainbow with no additional parts.  But I see RGB strips that have individually addressable LEDs which means there is somewhat complex digital electronics in each surface-mount package (along with 3 LEDs). 

Clearly then it is just a matter of some manufacturer finding a volume application of a surface-mount flickering LED in a choice of colors.  They're probably out there but just haven't reached the hobby market.

A flickering LED with three or four elements in it would be super, that would be a perfect fit!  I will have to think about making a board for two of my SMT 3-LED chips and an 8-pin PIC.  I'll probably use the same one I use on the Chuff-Generator, might as well leverage the parts I already am using and have all the init code written for.

I have strips with the 3-LED parts on them, but they're not individually addressable.  I've seen those on eBay, and they have a logic chip for each little group.  Some list the WS2811, which looks like it would do the trick.

It appears that some have a 3-LED ship with the logic build in, eBay: 371646419352

Right.  It's the WS2812 variant with the built-in IC chip with the serial data logic circuit.  I'm simply pondering if any manufacturer has found it profitable to develop the fabrication process to combine a simple LED with the simple flickering LED circuit in a surface-mount package.  I don't which came first, the blinking LED or the flickering LED, but one of them came first and was then I figure a simple adaptation to do the other.  The question is if it's worth the bother adapting the WS2812 process to put a flickering (or blinking) circuit into a commodity, garden-variety, surface-mount LED.

Why not buy a lionel version?  For Lionel the DCDS provides the fire box flicker.  For MTH, a PS-3 upgrade can have this effect as I have seen ditch light used that alternate the flicker on some PS-3 steam.

George, I like the effect I get from the four truly random flickering much better than the Lionel design.  I also like to have different colors of the individual flickering LED's to further enhance the effect.  I have a few Legacy models that have the flickering firebox, nice but not as nice as mine IMO.

I can do this simple circuit board, and assemble mine in a few minutes for less than $1.  The little board is only 40 cents from OSH Park.  The flickering LED's cost me about 10 cents each, and the resistors are less than a penny.  Where I'm putting these, I already have +5VDC from the Super-Chuffer, no problem there.

stan2004 posted:

Right.  It's the WS2812 variant with the built-in IC chip with the serial data logic circuit.  I'm simply pondering if any manufacturer has found it profitable to develop the fabrication process to combine a simple LED with the simple flickering LED circuit in a surface-mount package.  I don't which came first, the blinking LED or the flickering LED, but one of them came first and was then I figure a simple adaptation to do the other.  The question is if it's worth the bother adapting the WS2812 process to put a flickering (or blinking) circuit into a commodity, garden-variety, surface-mount LED.

Hard to say if someone has actually done that, but the WS2812B looks interesting, I spend a couple bucks and ordered some from China, after York I'll have something to play with.

I still have several MTH PS-1 steamers I plan on upgrading to TMCC with ERR boards.  If I use your optical signal generator and super chuffer, I don't need the 5V supply board if I add this firebox flicker board as the super chuffer board provides the power?

Needless to say, these locomotives will have quite a bit of your stuff in them.  Thanks!

Yep, there's enough power supplied by the Super-Chuffer to power this board, that's how I typically do it.  If you add it to another locomotive without a Super-Chuffer, you just have to come up with a 5V supply with around 40ma of power.  Another option is to change the resistors to a higher value and use a diode and capacitor to supply raw DC to the LED's, it just has to be filtered.  If you go with something in the 680-750 resistance range, you can power it from 18V track power using the diode and cap.  I'd use a 220uf 35V capacitor for this application.

Wouldn't it be grand if the four flickering LED's were on a PCB and I just had to solder a few parts on and be good to go?

IT still works great from the ones on the Right OF Way steamers! ROWI used the rectangular red LEDS in a row and a random blinking pattern to show flickering. I suppose it can be done better with those surface mount led's!

I like the flickering LED's as they don't just blink, but actually provide a real flickering effect.  With a bunch of them, the effect is really neat.  Stan's idea of the processor controlled blink is a good one, I may explore that idea.

I needed one of these for my current upgrade project, so I hacked out a prototype, it'll be nice to be able to just slap the LED's and resistors on a board and hook them up.   Here's the size, it's about the size of the boards shown above.  The thickness of this one is only 1/4" total, and the boards I have coming will eliminate some of that, they're thinner boards.  I did realize that I could shave a bit more off the thickness for run #2 by simply moving the resistors to the same side as the LED's, there's dead space there anyway.  That might be an option, though it's nice to that large flat area in the front to suspend this from the boiler wall.  That was the original reason for putting them on the back, so I'll have to think about that.

The way I mount this is to keep it about 1/8" from the lens on the smoke box opening, that helps further diffuse the individual points of light.  I have also ground the tips of the LED off, as they focus the light as well, the goal is to get the four LED's in three colors to blend somewhat by the time your eye sees them.  The camera doesn't show it, but the two LED's in the middle of the board are the red and orange ones, the ones at the edge are yellow.  I think the camera seems to boost those colors and wash them out.  The board is upside down in the picture, so the yellow ones will be on top in the firebox.

What about oil-fired steam engines that don't have a continuous, if varied, glow from the firebox?  Oil-fired engines have an intermittent yellow-orange flash that is more subtle appearing than coal-fired engines.

Well, if you want a totally different appearance than provided by the four flickering LED's, it would probably have to be a microprocessor based design with something like a small PIC processor.  That could obviously be done, but I didn't do it.

Here's the two versions I made, one runs from 5VDC from the Super-Chuffer (if installed).  The other one runs on track power.

Production item or kit?

So far it's just a prototype.  One issue is the flickering LED's are VERY sensitive to heat and almost every one I build I have to replace one or two of them.  I don't know if it's just the cheap eBay LED's or the internal circuit is just touchier.  I'm going to try making a couple with the iron turned down a bunch and see if 650F is just too hot for them.

Berkshire Junction still sells a "Cozy Campfire" board that I designed for them 15 years ago. They use only one flickering LED. But my PIC design actually has 3 random flickering outputs. So in the past I had advised people how to add 2 more LEDs to the board. Usually a red, orange , yellow combo.

Berkshire Junction has a lot of neat things. I never knew about them.  Elastic wire for telephone poles, etc. Might be good for a simulated catenary wire.  Welding light, campfire, etc. They are selling the electronics side of their business...semi retired I guess.

Gary E posted:

Berkshire Junction still sells a "Cozy Campfire" board that I designed for them 15 years ago. They use only one flickering LED. But my PIC design actually has 3 random flickering outputs. So in the past I had advised people how to add 2 more LEDs to the board. Usually a red, orange , yellow combo.

With flickering LED's, it's a whole lot easier to do these effects.  We have three or four campfires on our modular club modules that all use flickering LED's as the base.

My combo of LED's for the flickering firebox is red and orange on the bottom, and a couple of yellow ones on the top.  Obviously, you can change that up however you feel is right.

What amazed me was how many of these BJ sold. I used to supply them with 2-3 hundred every year.

Guns,

   John could this flickering fire box be installed in the Tin Plate 249 ERR up graded Engine you did for me?  Or is this not possible.

PCRR/Dave

Dave,

I don't know if the clearance is sufficient for that option, a lot of the tinplate doesn't offer much room.  I truthfully don't remember the exact details of what was inside yours to answer positively.

John

John,

  It is a small cab and that is why we did not install a regular 12V light bulb and socket, is the flickering fire box larger than a normal 12V light bulb with socket, or smaller.

PCRR/Dave

It is obviously larger as it's four LED's in an array as you can see above.

These look good John, is there an ideal location in the shell that the boards will fit into?

Also do they light the pan up and the fire box door ? I remember Alex doing this added light feature, but I believe it was to light up the glass sight box door

ADDED FIRE BOX GLOW TO THE LIONEL LEGACY GS-2 | O Gauge Railroading On Line Forum

J Daddy,

   From the looks of it, it's still to big to go into the 249 ERR.

PCRR/Dave

This is were I get my stuff for LED Custom Lighting effects and Upgrades.

http://www.ngineering.com/

J Daddy posted:

These look good John, is there an ideal location in the shell that the boards will fit into?

Also do they light the pan up and the fire box door ? I remember Alex doing this added light feature, but I believe it was to light up the glass sight box door

ADDED FIRE BOX GLOW TO THE LIONEL LEGACY GS-2 | O Gauge Railroading On Line Forum

There were indeed intended to light up the firebox in the cab.  I could apply similar techniques to the ashpan glow, I just haven't done it.

gunrunnerjohn posted:

  I do have this little module that supplies 5V to run stuff like this.

GRJ, do you sell these? I think I could do with some!

GRJ, those 5v boards would go great with the ERR cruise m since the supper chuffer needs 5v to operate.

Rod Miller