Hand Cranked Flashlight

[Watson A.Name - Watt Sun]

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:###
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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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[Gary Tait]

Whereas On Fri, 10 Oct 2003 01:42:46 -0700, Watson A.Name - "Watt

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.

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.

 

[R. Steve Walz]

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.

-------------------------------
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

 

[Don Klipstein]

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).

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 ([email protected])

 

[Si Ballenger]

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.

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

 

[Watson A.Name - Watt Sun]

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.

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]

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 ([email protected])

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###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
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Watson A.Name - Watt Sun]

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

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.

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###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
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@