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Hand Cranked Flashlight

Discussion in 'Misc Electronics' started by Watson A.Name - Watt Sun, Oct 10, 2003.

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  1. I made a hand cranked flashlight, sort of. I disassembled a defunct
    NED CD-ROM drive, and used the DC motor and gear assy that opens and
    closes the door, etc. I sawed off most of the plastic, leaving the
    motor and five gears. For a crank, I screwed an inch long screw into
    the cam gear, which when turned slowly, spins the motor fast. I
    soldered a superbright red LED onto the red and black wires from the
    motor and taped the LED to the frame (maybe epoxy it later).

    Now I can just crank the big cam gear and the motor puts out enough
    current to light the LED brightly. It takes two hands, so it isn't
    really practical, but for the first try, it's pretty good.

    Earlier, I took the motor by itself from another CD-ROM drive, and
    soldered a red LED to it. I can spin the shaft and light the LED
    brightly, but after a few times, the gear teeth make my fingers raw,
    so it's not really practical. But it's still kind of cool.


    --
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    ###Got a Question about ELECTRONICS? Check HERE First:###
    http://users.pandora.be/educypedia/electronics/databank.htm
    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
    @@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@[email protected]@[email protected]@@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@
     
  2. Gary Tait

    Gary Tait Guest

    Whereas On Fri, 10 Oct 2003 01:42:46 -0700, Watson A.Name - "Watt
    What I have around, is a DC gearmotor form a battery powered store
    display. I hooked it up to a small radio and got that to work. Now to
    add a clock sprong to it. Perhaps I cold use the recoil spring from
    one of the parts chainsaws about.
     
  3. -------------------------------
    Look here:
    http://www.armory.com/~rstevew/Public/LED_Ccts/EPE_LEDTorch.gif

    Uses a bipolar stepper, gear this up and put a rubber roller on it.

    -Steve
     
  4. Try with one of the better 525 or so nm InGaN superduper green LEDs. If
    that works, it may have some usefulness due to that wavelength being
    dozens of times more visible to night vision than red is. Even by
    photometric measure, Nichia green LEDs are more efficient than the most
    efficient 5 mm red ones, almost by a factor of 2 when moderately
    underpowered.

    If the voltage is on the low side, see if a transformer helps (not
    guaranteed to help). Try for not too great a turns ratio with the lower
    side having a design AC voltage of at least 12 volts (maybe a small one
    with a 120/240V dual voltage primary, used as an autotransformer? Maybe a
    24 or 36 or 48 or so volt center tapped secondary used as an
    autotransformer?)

    If you get voltage a little above optimum (current compromised), try
    fullwave bridge rectifying with Schottkey diodes (preferably lower
    voltage) and filtering with at least a 100 uF capacitor across the LED
    (InGaN LEDs, with average current of a few mA or more, are usually more
    efficient with steady DC than pulsed DC).

    - Don Klipstein ()
     
  5. Si Ballenger

    Si Ballenger Guest

    I've got one of the below dynamo flash lights and have wondered
    how it would work if converted to work with LEDs.

    http://www.netrap.com/soviet/dynamo-flashlight.html
     
  6. Got a Q for you. I bought some LEDs from Hosfelt, one of them, the
    25-377 green, I believe you mentioned on your web page. I found that
    one to be okay, maybe not so uniform in beam evenness. But the
    voltage drop at 25 mA is over 3.9V, more than a blue or white LED!
    Have you measured yours? I thought that to be too high for a green
    LED.

    I also bought some others: 25-366, 25-276, 25-502, 25-504. I was
    disappointed in these, especially the 10 mm 25-276. It throws a dark
    circle with four antennas on the wall, looks like a sputnik. It's the
    die pattern, but it shouldn't stay in focus all the way across the
    room. Have you ever seen such a LED?

    I've never had a problem with the ones I've bought from Nichia. But I
    bought a few blue LEDs for under a dollar each from a distributor, and
    I'm not happy. I've had at least two of them start to go intermittent
    while handling 25 mA of current. They might blink or flicker a little
    every few minutes, or even worse, go off for awhile.

    I ordered a hundred 3 mm white LEDs for $25 from a Hong Kong dealer,
    and will receive them in a week or so. That's 1/8 the price I paid
    for Nichias. I hope they're not as poor a quality as the blues I got.
    I'm just looking for feedback on others' experience with these low
    budget LEDs bought on Ebay.

    [snip]
    --
    @@[email protected]@[email protected]@@[email protected]@[email protected]@[email protected]@@[email protected]@[email protected]@[email protected]@,@@[email protected]@[email protected],@@[email protected]@[email protected]@[email protected]@
    ###Got a Question about ELECTRONICS? Check HERE First:###
    http://users.pandora.be/educypedia/electronics/databank.htm
    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
    @@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@[email protected]@[email protected]@@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@
     
  7. You can buy replacement light bulbs with LEDs from companies, if you
    want to try it. See www.ledmuseum.org for more info that you ever
    wanted to know about LEDs. Check the vendor links.

    I built my own by putting 3 LEDs with 33 ohm resistors in the base of
    a prefocus light bulb. But the new ones on the above web pages do not
    require a certain voltage, they have a circuit in the base that allows
    them to work with almost any flashlight. I'd like to get a few just
    to try them out.

    --
    @@[email protected]@[email protected]@@[email protected]@[email protected]@[email protected]@@[email protected]@[email protected]@[email protected]@,@@[email protected]@[email protected],@@[email protected]@[email protected]@[email protected]@
    ###Got a Question about ELECTRONICS? Check HERE First:###
    http://users.pandora.be/educypedia/electronics/databank.htm
    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
    @@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@[email protected]@[email protected]@@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@
     
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