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'LED Flasher Competition' from 1998

Discussion in 'Misc Electronics' started by Watson A.Name - 'Watt Sun', Aug 17, 2003.

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  1. [I posted this last night, 2003 Aug 16 11:00 PM, but I didn't see it
    show up on the server. I don't know why.]

    I was googling groups and I came across this post from 1998. It also
    talked about the Forever Flasher, AKA Infini-Flasher that we talked
    about here a week or so ago.

    He claimed that the Infini-Flasher was efficient and the only circuit
    that would run for 20 hours off .3 farad.

    I built the circuit at the following URL and talked about it in the
    SED, etc. newsgroups. It says runs 6 months off a 150 mAh battery.
    http://www.discovercircuits.com/PDF-FILES/3vledfs1.pdf

    The first one I built used about 100 microamps average at 3VDC and
    would run for 90 or so seconds off a 6800 uF cap. I built another
    one, and changed some parts values, and lowered the 4700 ohm resistor
    to 2200, which gave it a shorter pulse width, and that reduced the
    average current. Now it draws an average of 44 microamps and runs for
    over 5 minutes off the 6800 uF cap. It's getting really boring timing
    this with a stopwatch.

    This morning I made further mods and I think the current is down to 12
    to 14 microamps, but since the DMM draws a couple uA, I have to kind
    of finagle that into the total.

    Here are the changes I made:
    Was: Changed to:
    4.7M -> 10M and 3.3M in series

    0.68 uF -> 0.1 uF ceramic disk

    2907 and 2222 -> 2N4403 and 2N4401

    680 ohm -> 1.5k

    4.7k -> 2.2k

    47 ohm -> 220 ohm

    With these values and an average current of less than 14 uA, the
    pulses are 1 every .9 sec or about 1.1 Hz. It will run off the 6800
    uF cap for over 11 minutes.

    I figure that it would take 130 of the 6800 uF caps in parallel to run
    this circuit for 24 hours, or a total of about .9 farads. That's
    about 3 times as much capacitance as the Infini-Flasher. Which seems
    to indicate that the Infini-Flasher is drawing only 6 or 7 microamps.

    Slowing the flash rate down to much less than once a second will also
    reduce the average current. That's how he made the Infini-Flasher
    last a lot longer on the .3F caps. I can incease the 13.3M resistor
    to 22 Megs, which will probably give it about 2 sec between flashes.
    If I get it to run off the 6800 uF cap for 20 minutss, then the 24
    hour cap would need to be less than half a farad.

    I didn't want to have to use the inductor. I presume this is used to
    boost the supply V up to the LED's V. When my circuit gets down to
    less than 2V, the LED starts to dim and the circuit soon quits. If I
    were to use a V boost circuit, it would probably operate down to a
    much lower voltage, like the Infini Flasher.

    Here's a part of the original post from 1998.
    ----------------

    This is called the "Forever Flasher" because, given an adequite
    supply of sunlight once a day it will flash forever (*even*
    during night-time and low light conditions).

    As you said it would be pretty trivial to make an LED flasher
    that ran on solar cells. This one is special because it will
    run for about 24 hours or so in complete darkness with only .3F
    worth of caps. I did indeed try an LM3909 for this and it only
    lasted about 20 minutes on the same caps!

    This is the only circuit idea I know of that will run for about
    24 hours in complete darkness flashing an LED off of .3F worth
    of caps. Can someone come up with another circuit that's more
    effecient? "The sci.electronics.design LED Flasher
    Competition!" :)
    ------------------

    --
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    ###Got a Question about ELECTRONICS? Check HERE First:###
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    My email address is whitelisted. *All* email sent to it
    goes directly to the trash unless you add NOSPAM in the
    Subject: line with other stuff. alondra101 <at> hotmail.com
    Don't be ripped off by the big book dealers. Go to the URL
    that will give you a choice and save you money(up to half).
    http://www.everybookstore.com You'll be glad you did!
    Just when you thought you had all this figured out, the gov't
    changed it: http://physics.nist.gov/cuu/Units/binary.html
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  2. parman

    parman

    2
    0
    Jun 6, 2010
    i tried something different

    I tried something different i used water battery as power source and a joule thief with a 1000 uf capacitor to blink superbright white L.E.D and its been one month and the led is blinking at interval of 8 seconds.

    step 1 rip off aa battery to get carbon rod and the zinc strip
    step 2 construct water battery ie dip both the carbon rod and zinc strip wires connected in water
    step 3 complete the circuit carbon rod as +ve and zinc as -ve to joule thief
    all is done

    u can combine solar cell to this also
     

    Attached Files:

  3. parman

    parman

    2
    0
    Jun 6, 2010
    more brief symathic

    improved bay adding a solar cell
     

    Attached Files:

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