I will pay you to figure this out

Discussion in 'The Projects Forum' started by The Ignorant Artist, Sep 25, 2012.

  1. The Ignorant Artist

    Thread Starter New Member

    Jul 31, 2012
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    Hello Forum,

    There is a chance this will be deleted outright. Please moderators, have compassion. This is the only place I can think of that might be able to help.

    A while ago, I posted asking for advice on how to make an led circuit remain lit without interruption for as long as possible using batteries as the sole power source. Here is the original thread:
    http://forum.allaboutcircuits.com/showthread.php?t=73453

    After reviewing the information you all so kindly gave I have come to the realization that I do not have the time to teach myself about circuitry. I work full time and spend whatever remains of the week making art for an upcoming show. I would like to hire someone to completely figure out the technical aspects of my project. I need you to create a working prototype, a parts list, and an idiot proof diagram of your device. I invite you all to make a proposal stating the price for your services, the length of time your design will remain illuminated, and the approximate cost to produce one of your device.

    The concept:
    I would like to seal an illuminated LED circuit in a block of acrylic resin about the size of a small paperback book. The LED should remain lit for as long as possible, hopefully a number of years. It should be bright enough to read by if the resin block is held very near the text. No remote charging methods or plugs may be employed, though a solar cell would be permissible if it could function from within the acrylic resin. Please email me for any clarification you require.

    Thank you.
     
  2. MrChips

    Moderator

    Oct 2, 2009
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    You have to take into consideration two things:


    1. Power in - i.e. what is the power source
    2. Power out - how much power is consumed

    (2) Let's deal with the second first.
    The power consumed can be reduced substantially by turning off the LED when not in use. Hence you need some kind of switch. If this is going to be sealed in acrylic the only solutions I can think of are:

    1. a mercury switch
    2. an accelerometer to detect motion.

    (1) The power source will either be a non-rechargeable battery or a rechargeable one. Methods of recharging are:

    1. solar cell
    2. inductive pickup
    3. magnetic motion generator (aka shake flashlight)
    Choosing 3. will also solve problem (2) above.

    So there you have it. It is a perfectly doable project.
     
  3. The Ignorant Artist

    Thread Starter New Member

    Jul 31, 2012
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    The LED must remain lit at all times. There can be no switch. It would be acceptable for it to dim when running low on power if a solar cell and rechargeable battery were used.
     
  4. MrChips

    Moderator

    Oct 2, 2009
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    Why leave the LEDs on if no one is watching? We're talking conservation of energy.
    Your batteries might run 10 times longer if you use intelligent power conservation.

    (Our fossil fuel supply might have lasted 10000 years if we were smart.)
     
  5. wayneh

    Expert

    Sep 9, 2010
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    I'm wondering how practical solar is. Will this ever sit in direct sunlight, for instance on a window sill? Could it contain a "large" solar cell, say 2x2" or more?

    If it must rely on ambient room lighting and is limited to a, say, 1" square panel, it's just not much power to deal with.
     
  6. Sensacell

    Well-Known Member

    Jun 19, 2012
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    Hmmm.

    What you are asking for may not be practically attainable.

    The functionality you desire would make a fantastic product! (were it practical)
    I have never seen a device that meets these specifications offered anywhere.

    I am sure you could do it using an impractically large solar panel and battery, way beyond the scale of what you describe.

    Physics, it's a bitch.
     
  7. praondevou

    AAC Fanatic!

    Jul 9, 2011
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    Is this part of an art project or what is the purpose? What text do you mean by "the text"?

    Is it just a fancy rechargeable flashlight?

    Where will it be used? Is it fixed somewhere or mobile? What is the ambient light exposure?
     
  8. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    I would start by comparing the desire of an everlasting LED with some existing art, such as the solar powered garden LED light. You can read from it, it runs for a few hours every night, it's rechargeable off a few square inches of solar panels.

    It WILL be off most of the time but it could work for a long time. My lights go years and they get exposed to lots of weather.

    I do think a better charging mechanism would be in order, such as magnetic induction or sneaking out a pair of tabs for direct a connection.

    Just how much room is inside this for parts? Is the entire shape to be clear, or how much room can the supply use?
     
  9. Wendy

    Moderator

    Mar 24, 2008
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    There are other schemes besides solar, I mentioned one in the other thread that was ignored.

    We generally do not allow multiple threads on the same subject. I am having an internal debate whether to merge these two, I haven't decided yet.

    The reason is in the 1st paragraph, you were offered alternatives, it is unknown if you weren't interested or didn't see it. It could (though maybe not) meet your requirements. Unless you show you have read it by replying we will never know.
     
  10. BMorse

    Senior Member

    Sep 26, 2009
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    So does this LED have to basically illuminate the whole acrylic block evenly? Or can it be brighter say in the center then basically fade out to the edges?

    As for it lasting years, hmmmm, can it last for a few weeks, or maybe a month?

    Would it be acceptable for the device to "power" down when ambient light from its surrounding is at a certain brightness? Or does it have to stay lit all the time?
     
  11. wayneh

    Expert

    Sep 9, 2010
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    This project was in my head in the shower this morning and I'm convinced inductive charging is the most elegant solution. Maybe because my inductively charged electric toothbrush was sitting there nearby.

    Surely a work of art can spend time sitting on a display platform that doubles as the inductive charger. These are even available ready-made and can be quite attractive. Just google for images of inductive chargers. Here's one:
    [​IMG][​IMG]

    The pickup coil in the artwork could be beautiful shiny copper or maybe a silvery or golden foil. I wonder if you could use salt water?

    The OP may also want to look at what this guy is up to.
     
    Last edited: Sep 26, 2012
  12. DMahalko

    Active Member

    Oct 5, 2008
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    shortbus likes this.
  13. bountyhunter

    Well-Known Member

    Sep 7, 2009
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    You should use some kind of photocell sensor to reduce or turn off LED current draw based on surrounding light. You don't need a reading light if there is other light around you. This is an easy feature to implement and would allow the user to "turn the unit off" just by setting the unit someplace that gets light. That would greatly extend battery life.
     
    Last edited: Sep 26, 2012
  14. The Ignorant Artist

    Thread Starter New Member

    Jul 31, 2012
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    Thanks for all of the great suggestions. You are all right, this basically is just a fancy rechargable flashlight. I mentioned using it at a reading light only to give a rough idea of how bright the device would ideally be. The purpose of the light would not necessarily be to perform a function, but rather to create a persistent presence in the life of whoever owned it, sort of like those old Tamagatchi digital pets. Because I declare that the object is ART and not a toy, it would be much less likely to get lost in the laundry hamper than many a poor Tamagatchi. The devices would simply mark the time that the power source remains functionally charged. They would in effect die, causing the owner to reflect on the object's lifespan and consider how to dispose of it.

    The light should be as autonomous as possible and feel as alive as possible. This is why I feel that any charging solution (plug, induction plate, ext.) other than a small solar panel embedded in the resin would detract from the overall effect. This could be a maximum of 4"x6".

    A light detecting switch might also be acceptable, but only if it dimmed the output of the LED gradually based on the amount of light it detected. A hard on/off would not work.

    Thanks again-
     
  15. MrChips

    Moderator

    Oct 2, 2009
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    When I used the word "switch" I didn't mean a physical hard ON/OFF switch. I was referring to an intelligent means of controlling the power so that it is not wasted when not needed.

    I would not be inclined to design an object that is discarded when the power runs out. I follow the philosophy of the Long Now Foundation:

    http://longnow.org/

    and would rather design and build something that lasts forever. I have ideas for a Forever Clock that runs forever and never needs setting the time or power replacement.

    With that in mind, seems like a solar panel is the only solution for your project.
     
  16. bountyhunter

    Well-Known Member

    Sep 7, 2009
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    Easy to do with a photo cell and an op amp controlling the current source that feeds the LED.
     
  17. bountyhunter

    Well-Known Member

    Sep 7, 2009
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    I would give it life by having a vibration sensor that modulated the light intensity so it would respond to sound or talking.
     
  18. BMorse

    Senior Member

    Sep 26, 2009
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    I have an idea (that I think would work very well for what you want) I won't disclose too much info on here yet, until I can build the prototype (I already have some components on order).... the whole "feel alive as possible" is what intrigued me, I did some research, found what I think is a solution to what you want, and it could last for years, depending on how much "interaction" it gets from the user and its environment, it is actually quite simple, and very autonomous, as long as it gets its stimuli, it will keep working (in theory it works perfectly, but we shall see), the more stimulus it gets, the more vibrant and "alive" it is going to be, no external power sources or charging units needed.... just interaction from the user (not much interaction is really needed, just a little "attention", toss it in a back pack and carry it around, ride around with it in a car, take it for a bike ride, etc....).... but the best thing is, if it doesn't receive the input it needs, it will die, but can be revived, depending on how long it has been "dead" for.

    either way, I think the whole "alive" thing has gotten me curious and I will be hopefully tinkering with a circuit by next week....
     
  19. MrChips

    Moderator

    Oct 2, 2009
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    I was thinking along the same track. You can use micro-power MCU and LCD and the thing can run for years. Add a solar cell or shake generator and it will run for ever. If you're interested we can discuss this on a private forum.
     
  20. BMorse

    Senior Member

    Sep 26, 2009
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    Nope, no LCD??, no shake generator, no solar cell, or low power MCU for my idea..... just a few passive components and 1 IC :cool:

    I guess I could add a low power uC and and RGB LED (although this would consume more power).... then I can make it have "mood" swings :D
     
    Last edited: Sep 27, 2012
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