After much time trying to figure out how I can build what I wanted I was forced to make few changes (mainly remove the set-dollar amount of this "ultra-low cost venture") and just add more updated specifications/clarifications to the front page of this project. I am leaving the original specifications below as a historical record of the evolution of this thread.

=========================================================
This thread is all about figuring out what I need. It has been a long, fun, and adventurous journey (spanning many tangents) in which I have invested a lot of time [and money] thus far, but unfortunately still failed to get a good technical outline of what the two circuits I am looking to build will look like.

The non-technical explanation of what I want comes in two parts as there are two different (but closely related) projects that I am trying to shape with the help of this thread (its coming together though...slowly):


ProjectOne: A simple sign that stays on for as long as possible and can be built cheaply as possible

• LEDs will be inserted into the "cells" of a 9.5"x5.5" (~24cm x ~14cm) "clear" Coroplast (signboard/corrugated plastic/political sign board):

• The Coroplast will be stenciled with a Fusion Plastic black spray paint

• Will use 4-8 RBG LEDs that do what is called "slow flashing" (no logic circuit required - it is built into the LEDs) exactly as shown in this video: http://www.youtube.com/watch?v=epoVPB6wOuo

LED SPECS:
LED Size: 5mm
LED Color: water clear
Voltage: 3.2-3.6V
Current: 20mA
View Angle: ~ 25degree
Luminous Intensity: 5000-5500mcd

• The Coroplast sign will be attached to metal objects outside with 2-4 N35 (or stronger) 1cm x 1mm cylindrical rare-earth (neodymium) magnets to be glued directly to the Coroplast sign

• I want the sign to last for 14 days, but only care for it to be lit up after dark (or 8pm) and stay on until 3am.

ProjectTwo: An animated sign that does an "old neon sign flicker effect" at random intervals that can stay on as long as possible and can be built as cheaply as possible

Same as ProjectOne, but it animates the sign in the same manner as the neon sign in this video at random intervals: http://www.youtube.com/watch?v=2Uxk70BjH68&NR=1







NOTES:

• I am planning to make at least 1000 of these signs
• I have no idea how to power ether one of the two proposed designs...nuclear fusion anyone?
• I am curious if a buck-boost LED driver circuit would be able to (significantly) increase the life of the battery.
• How to synchronize the RBG slow-flashing LEDs (especially with out the use of the micro controller; especially for ProjectOne)?
• No idea what components I will be using yet, other than the LEDs outlined above
• Using capacitor-backed circuits
• Using timer circuits
• Using dark-detecting circuits
• Weatherproofing: soaking the circuit board in epoxy would do? Any better ideas?
• There is no planned maintenance for these signs, if only a battery change (which is not even something I am planning on as there is low chance of recovering these signs after placement)
• Using the PIC10f200 PIC10f202 pic12f508 PIC12F509 (I could not figure out the difference between the last two, what is it?) for "animation" (the broken-neon-sign-random-flashing effect) (I've purchased EasyPic6 development platform after the recommendation of one of the posters)

\/===============THE ORIGINAL POST FOR HISTORICAL PURPOSES===============\/




Hello everyone!

I'm ZigZag!










Guys, I could really use your technical expertize:

Executive summary:

I'm working on a currently-zero-ROI project (needs to be as cheap as possible). Basically, I need to backlight a 5"x10" "clear" (it looks white not clear, but it is called clear) Coroplast (aka corrugated plastic, aka sign board). Ideally I would like the sign to be visible from 50+ feet away (during street-lit conditions) for 7+ nights while animating in different colors (e.g. if it can turn on and flicker, like an old/cold neon sign does, and then slowly/smoothly transition through 3-4 colors before turning off and then after few seconds restarting all over again with some randomness built in) for under $ 1 USD (ha! I know! What would be more reasonable?) (would buy enough parts for 100-500 of these at once). I could live with a sign that is visible in street-lit conditions from 20 feet away for 2 nights and is backlit with a white led for under $1.65 (better estimate?) if I source 1000-2000 at once. Depending what this discussion will yield, I may do some of both (more of cheaper kind and less of the fancy kind). Price = excluding batteries. This is for outdoor use.


THE BIG A$$ THROWIE!

$ It needs to last 2-7 nights $
$ It hast to be visible 20-50 feet away in street-lit environment $
$ It cant be too heavy (sign will be held by 1-4 magnets) $
$ I would prefer to have these signs animated in multiple colors, but will deal with only white $
$ It has to be cheap, really cheap (yet satisfy the minimum requirements) $




*** I would really prefer 7 nights, but if 2 nights is 2x or more cheaper I would have to deal with only 2 days (it does not have to turn off during the day, but it will save on power)
*** I can live with the sign being visible 20-30 feet away in street-lit conditions
*** I would rather only use one magnet (cost issue) but if it can stay on for 7+ nights and/or be visible at 40-50+ feet away 4 magnets could be used
*** @$4/sign=no go! @$3/sign=will bleed me to death slowly @$2/sign=will keep my fridge empty for 2 months @$1/sign=I will loose some weight dieting, but would be an overall a really happy camper!






# I know very little about electronics and circuitry (willing to learn).

# I do not have any components yet except Coroplast and a breadboard to test circuits.

# I understand the difference between different metrics used measure light that is radiated by LEDs, but as I've never played with any high-powered LEDs I do not have personal experience as to how these numbers translate into "backlighting Coroplast and being visible at X feet away"

# I think battery can be saved, if needed, by using a sensor that can tell if it is light or dark out and turn on or off the LED ( e.g. http://www.evilmadscientist.com/article.php/nightlight )

# In the aforementioned link there are comments about how to increase the simple circuits productivity at minimal cost (adding a mosfet), but I do not know how it would apply to me (batt life vs. cost)

# I think the magnets will hold at least a pair of AAA if I chose to go with 4 of them per sign (costly, but...)

# I planned to source things from eBay and sites like Mouser, but I need at least a hundred of these already made by the second Thursday of August, so I have limited time for experimentation, if any (e.g. for visibility distance) due to shipping times.







Please let me know of my options and help me design a circuit, PLEASE!

 

What kind of patterns are you thinking about?

I don't think you'll be able to buy components as cheap as you need, but I've learned it is a matter of luck.

I've had single LEDs flash for a month from 2 AAA batteries. My absolute best deals on LEDs is around 10¢ each, which is a no go from what I'm hearing. Old colors, like red, green, and yellow are cheaper, maybe much cheaper. Blue and white is expensive.

I suspect you need something using a micro controller, though you might get by with CMOS chips for the patterns. The more complex the more expensive, though a microcontroller is a flat fee for complex patterns. They are also expensive by your standards, around $1. Overall your budget is a killer though.

Simple flashing is cheap and easy, less than a $1 (discounting LEDs). Things like rotation or moving is easy, and fairly cheap, $2, also discounting LEDs. Things like complex patterns is not easy, nor that cheap. However, if you learn PICs (a brand of microcontroller), it approaches a flat fee.

None of this counts labor, which is substantial. You will need to find a strong, inflexible material to mount components on. Cardboard would almost work, but it really can't flex much, if at all. Wood might work, you can drill holes through it to mount LEDs. You can use superglue to mount the parts upside down. Be prepared to learn how to solder.

Give us a pattern. If you don't want to give us exactly what it is draw something similar with a similar number of LEDs up and go with that. The circuitry won't care.

What part of the country do you live?

 

Have you held an LED flashlight behind the plastic to check on viewing distance?

 

I suspect the cost of LEDs is going to be a killer. The OP is dramatically undervaluing the cost of components. A simple battery holder can be 69¢.

Basically he may be able to kludge a lot of the parts, but some of the high tech parts (LEDs included) add up in costs. At this point we're going to have to wait for input.

 

As someone mentioned last time one of these came up make sure you don't cause another Mooninite scare.

 

These RGB LED's I got from Vishay were really bright, and could possibly only require 1 per sign if diffused properly.... http://www.youtube.com/watch?v=L0REd2ZFUCc


In this picture I used some 10mil corrugated "clear" plastic and back lit them with a 60 watt colored incandescent bulb....

but to try and do this all with just $1.00 per sign, would be a stretch, you would have to spend thousands to get good price breaks on each component you would have to use.....




B. Morse

 

Bill_Marsden, Bernard, gruzina, Markd77, BMorse - Thank you for your replies! Wow!

 

What kind of patterns are you thinking about?

Bill, nothing really is set in stone, and I would like everyone's ideas too!
I want something that will attract attention, but will not be annoying on the eyes. I may even ask few places to allow me to put my signs up inside.


Here is what I was thinking:

Loop:

Flicker on (random length 4-10 seconds)--->smooth light transitions (random length 2-7 seconds per color)--->Turn off (or flicker off).


I know randomness it possibly an extra component or an upgrade to a more expensive component, but I may make some (not many) anyway to put in more hip places.





http://www.youtube.com/watch?v=E_KVQ5EBTBg - cool flicker!

http://www.youtube.com/watch?v=Yd6z3x8KjOQ - flicker

http://www.youtube.com/watch?v=2Uxk70BjH68&NR=1 - real life flicker


http://www.youtube.com/watch?v=zTc00syZ9gA - smooth color transition effect

 

I don't think you'll be able to buy components as cheap as you need, but I've learned it is a matter of luck.

I can balance my cost per unit with my purchasing power - but it is a triple edge sword: I can reduce price by buying in bulk or I can reduce overall cost, but increase the price per unit by buying less quantity and paying more per unit, but keeping overall costs down.

I've had single LEDs flash for a month from 2 AAA batteries. My absolute best deals on LEDs is around 10¢ each, which is a no go from what I'm hearing. Old colors, like red, green, and yellow are cheaper, maybe much cheaper. Blue and white is expensive.

what do you mean it is a no-go?

I suspect you need something using a micro controller, though you might get by with CMOS chips for the patterns. The more complex the more expensive, though a microcontroller is a flat fee for complex patterns. They are also expensive by your standards, around $1. Overall your budget is a killer though.

- I kind of figured the microcontroller is the way to go in the high-end version of this.

Simple flashing is cheap and easy, less than a $1 (discounting LEDs). Things like rotation or moving is easy, and fairly cheap, $2, also discounting LEDs. Things like complex patterns is not easy, nor that cheap. However, if you learn PICs (a brand of microcontroller), it approaches a flat fee.

- I'll learn!

None of this counts labor, which is substantial. You will need to find a strong, inflexible material to mount components on. Cardboard would almost work, but it really can't flex much, if at all. Wood might work, you can drill holes through it to mount LEDs. You can use superglue to mount the parts upside down. Be prepared to learn how to solder.

- I'm unafraid and I can learn fairly quick. I was thinking epoxing the components dirrectly to the Coroplast material because it is rigid - more rigid then a cardboiard, but after you've mentioned this - I started thinking of the shadows they would cast. I could do Coroplast on both sides - one side that I want to light and the other side where I'll epoxy stuff. and then connect both sides together. I already know how to solder.

What part of the country do you live?

I'm in Cleveland, Ohio

I suspect the cost of LEDs is going to be a killer. The OP is dramatically undervaluing the cost of components. A simple battery holder can be 69¢.

- in the worst case scenario - I will glue the batteries to the Coroplast. Actually this was the way I hoped to make the the cheaper signs anyway

Basically he may be able to kludge a lot of the parts, but some of the high tech parts (LEDs included) add up in costs. At this point we're going to have to wait for input.

-
I have found some amazingly bright units on eBay and they produce 250,000 mcd - at less then 1w for a dollar a piece. They draw a lot. I am not sure how to pick the best best battery for them, but I think just one of those may give me at least 20 feet visibility, but again I do not know how bright they look like in practice.

 

Well, the only way I can think of doing something like this vaguely economically would be to use a small uC (microcontroller) like a PIC10F200 that sequences the colors. Someone would have to write the program, obviously.

The PIC10F200 uC can be purchased for as low as $0.30/ea in large quantities; has six pins; power, ground, and the rest are I/O pins. One has a weak pull-up, and isn't really usable to drive anything - it's just an input. So, three outputs driving three transistors that switch three separate inductors to provide a voltage boost to drive current through the LED strings.

The value of the inductors is sort of up for grabs, but I'm thinking in the 100uH-500uH range. It sort of depends on how many LEDs you're going to want to operate. Since the LEDs probably won't require more than around 25mA current, you likely could use RF chokes instead of power inductors, which would likely be less expensive and certainly more compact.

The size of the circuit board will have a huge influence on the total per-unit cost.

 

Have you held an LED flashlight behind the plastic to check on viewing distance?

Yes sir! (I'm glad you've asked)

Here are some pictures:





Captions:

Photos 1 & 2 are of the LED flashlight I've used to backlight this "clear"/natural Coroplast material. I do not know any specs on it and I think it was bought at Murrays Discount Auto Parts (which was renamed to Murrays/O'Rilleys not too long ago or Home Depot (or both)


Photos 3 & 4 are of me holding the flashlight right up against the material.


Photos 5 & 6 are of me holding the flashlight about a foot away from the Coroplast material. It actually looks much brighter on the last picture then it really is because iphone 3G's camera sucks like that

 

I would suggest you to biuld a basic Flip-Flop device... just like the lights in train rails pass .
http://skema-elektronik.blogspot.com/2008/11/basic-analog-flip-flop-schematics.html

It is easy and cost effective to build.... multiply the schematic and you will get more light doing the same flip-flop action...

Is there a way to slow down the rate of the flashes?

 

As someone mentioned last time one of these came up make sure you don't cause another Mooninite scare.

http://gizmodo.com/351174/boston-getting-leded-on-athf-mooninite-anniversary


Yea I've thought about this, looks like this will not phase people too much. My stuff will look a bit more obvious too.

 

These RGB LED's I got from Vishay were really bright, and could possibly only require 1 per sign if diffused properly.... http://www.youtube.com/watch?v=L0REd2ZFUCc


In this picture I used some 10mil corrugated "clear" plastic and back lit them with a 60 watt colored incandescent bulb....

but to try and do this all with just $1.00 per sign, would be a stretch, you would have to spend thousands to get good price breaks on each component you would have to use.....




B. Morse

Brent, very nice LEDs AND the PCB mill! I must have missed the price, how much were the RBGs?

The stand/bar came out to be spiffy! Is that whole thing made out of 10mm Coroplast? Because it looks like brushed metal to me! Speaking of prices, how much was the one on my left (seriously)? I would not even know where to find a model, but if you did the hiring, or know the price, it would be a useful piece of info.

Light diffusion is something to ponder about as well. I was thinking of using the LEDs that have a lens angle of 120+ degrees, and even though Coroplast and wide angle lens will diffuse some light, I understand I have to look at some other options. I just had an idea, looking at the florescent fixtures above me, to take the clear diffusional material and cut it up and layer it onto Coroplast in front of the LED. I also might do some more research on what else I can use.

 

Brent, very nice LEDs AND the PCB mill! I must have missed the price, how much were the RBGs?

The stand/bar came out to be spiffy! Is that whole thing made out of 10mm Coroplast? Because it looks like brushed metal to me! Speaking of prices, how much was the one on my left (seriously)? I would not even know where to find a model, but if you did the hiring, or know the price, it would be a useful piece of info.

Light diffusion is something to ponder about as well. I was thinking of using the LEDs that have a lens angle of 120+ degrees, and even though Coroplast and wide angle lens will diffuse some light, I understand I have to look at some other options. I just had an idea, looking at the florescent fixtures above me, to take the clear diffusional material and cut it up and layer it onto Coroplast in front of the LED. I also might do some more research on what else I can use.

Actually I got 20 of them as samples from Vishay !

The "Bar" is made of brushed metal, the top and shelves inside are of diamond plate aluminum, and the panels were backed by the 10mil plastic, then the lights are just "diffused " in the inside, I did not directly shine the light right onto the plastic....

As for the models, they were hired by Cintron Energy Drinks, who also hired me to do the "traveling bar"... (see the worklog here for the Bar >>http://www.morse-code.com/id138.htm)

I also found that by gluing a piece of a Hot Glue stick right on the end of the LED it diffuses the light quite nicely...

B. Morse

 

Well, the only way I can think of doing something like this vaguely economically would be to use a small uC (microcontroller) like a PIC10F200 that sequences the colors. Someone would have to write the program, obviously.

The PIC10F200 uC can be purchased for as low as $0.30/ea in large quantities; has six pins; power, ground, and the rest are I/O pins. One has a weak pull-up, and isn't really usable to drive anything - it's just an input. So, three outputs driving three transistors that switch three separate inductors to provide a voltage boost to drive current through the LED strings.

The value of the inductors is sort of up for grabs, but I'm thinking in the 100uH-500uH range. It sort of depends on how many LEDs you're going to want to operate. Since the LEDs probably won't require more than around 25mA current, you likely could use RF chokes instead of power inductors, which would likely be less expensive and certainly more compact.

The size of the circuit board will have a huge influence on the total per-unit cost.

Thanks SgtWookie!

I had the hunch that the more expensive version of this project will require a microcontroller. I will have to figure out how to code for the animation. Do you think that the flicker effect is possible with the PIC10F200 along with the gradual/smooth color change?

I also figured that most microcontrollers will not be able to pull the LEDs. I was thinking a MOSFET. You gave me some new components I've never heard about: inductor and the RF chokes (I'm reading about them on Wikipedia now).

The size of the circuit board has to be smaller then 4"x8", except that the cost of the circuit board would be the only issue.
http://forum.allaboutcircuits.com/member.php?u=12669

 

Actually I got 20 of them as samples from Vishay !

The "Bar" is made of brushed metal, the top and shelves inside are of diamond plate aluminum, and the panels were backed by the 10mil plastic, then the lights are just "diffused " in the inside, I did not directly shine the light right onto the plastic....

As for the models, they were hired by Cintron Energy Drinks, who also hired me to do the "traveling bar"... (see the worklog here for the Bar >>http://www.morse-code.com/id138.htm)

I also found that by gluing a piece of a Hot Glue stick right on the end of the LED it diffuses the light quite nicely...

B. Morse

Wow, neat! Super cool of Vishay (I'll check them out)!

I'm going to guess that the plasma cutter is yours, or you have free access to it, but in the off chance that you hired out this leg of work (or know how much it would cost), could you tell me how much one of those side panels (for example the ThreeOlives panel) would cost to cut out?

 

Yes, I have free run of the CNC Plasma cutter.... I had actually made inter-changeable panels for the Bar, so depending on which show, or product they were advertising, there would be a different side panel, each panel cost them $250.00, that included the design, and fabrication (finishing, bending, etc.) the panels were roughly 42" tall x 24" wide.... for cutting jobs I do for most people on the side it usually runs around .15 cents an inch, plus material costs...

B. Morse

 

I was digging through my project boxes and found that I have some circuit boards (the whole 5 of them! but I can cut them up in smaller pieces).

I also have ferro-magnets (about 2000 of them) they are kinda big and no where as strong as the neodymium/rare earth magnets. I figured maybe I can use them to make components like the Jewel Thief ( http://www.evilmadscientist.com/article.php/joulethief ), but I don't know if replacing iron core with a magnet is a good idea (for some reason it seems like it would help). If they are pretty worthless, I will just go with my original idea and use these for their sticky power.

I have about a hundred of what I think should be resistors (I bought them 3-4 years ago with to slow down loud computer fans, but never got around to it. I do not see color coding on them (at least I do not recognize it): small glassy cylinder with red on both sides only to be divided by a clear line.


I also have a box-full of various shrink tubes. I even have a huge roll of 3" shrink tube in which I can stick the whole darn circuit board (exactly why I bought the 3" stuff).


I also have what I consider a nice 60W Weller soldering iron with adjustable temperature control and a digital temperature readout.

 

Yes, I have free run of the CNC Plasma cutter.... I had actually made inter-changeable panels for the Bar, so depending on which show, or product they were advertising, there would be a different side panel, each panel cost them $250.00, that included the design, and fabrication (finishing, bending, etc.) the panels were roughly 42" tall x 24" wide.... for cutting jobs I do for most people on the side it usually runs around .15 cents an inch, plus material costs...

B. Morse

OOOH! Nice! I think they got a deal! It looks so awesome and it is an investment because they can keep changing up the panels and you get extra work as well.

I'm guessing you meant 15 cents/sq inch or inch of a design not .15 cents/inch because, well... haha that's a DEAL!