Want a LED Flashlight with only 1AA?

man o man! I Found it, I got a circuit from Jolly Old London, UK. And guess what?

After playing with it a little bit, and trying this resistor and that resistor, I found a good combo, I'm going to still play with it and see how much more I can get out of it, but this is what I got, A little flashlight that takes one AA and had been on for over 34 hours and is still working and giving off good brightness.

I don't know if it's as good as a CMG lite I don't have one to compare. And this is a real simple circuit with only one draw back, you must wind a coil your self!

I'm going to go looking at the camping stores to see if I can get a CMG today, I'm on vacation and have all the time in the world, man I'm so freaked out by this lite, I'm going to take some pics tonight and show the brightness.

Now all I need is to find a small cool looking flashlight to put these in, any ideas? Please let me know?.

Eater. See the Dealer's Corner topic on the main page for good Infinity prices on last year's model. The new one is anodized, but I like to strip the coating off anyway, so I don't view the new models as improvements. Camp stores will run you $18-$20, and if you want the new, my bet is they don't have them yet.

Sounds neat eater, I would like to hear how it compares with the Infinity. It would be great if it is brighter. 34 hours is pretty damm good. I can`t recommend a light to put it in as not sure how big the curcit is.

Well the whole think is only 4 parts, one LED, one transistor, one resistor, and A coil, that's it, and it's been running now for 57 hours, on the same 1AA battery, this thing is so cool, here is the break down.

saterday night 10:15pm Started 100%

sunday night 10:15pm 75%

Monday night 10:15pm 45%

Tuesday morning 7:30am 40%

I think this will last longer and longer because the LED keeps getting more and more efficient as the battery goes down. Even so this morning befour the sun came up it was still bright enough to light up my whole bedroom very well.

I'm going to Las Vages for 3 days, I have someone watching the light for me and will let me know when it's out!, but the way it's going I think it will still be lit when I get back.

Just one question though, Not many people are asking questions? is this something you guys are interested in? or just me? I know it's reinventing the wheel, but my point is that we can make this our selfs?

Eater,
Some pictures would be really
NIFTY-if u can do it??

optoelectronx

There is a web site in the UK I was recently told about that sells among other things, a little project kit to make a LED flashlight that runs on one 1.5 volt button cell (mercuric oxide one but I reckon regular sized alkaline types will work too I expect). As with "Eater`s" design it is very basic and you have to wind your own coil, it may even be the same circuit. It comes with a miniature keyfob style plastic case too but I don`t know what led is used. The web site also sells Nichia 5600mcd whites so it may be one of them?
Anyway I ordered one so will find out soon enough and if it`s any good I`ll post the web address. As it is, the battery life doesn`t look good but as I said I reckon it`d work with a normal cell like AA or even why not go for extreme battery life and use a "D"! Imagine how long that one would burn?

Note that he doesn`t seem to sell to the States, only UK and western Europe but he might be persuaded, who knows? I`ll keep you all posted.

Eater - Don't be discouraged by the lack of questions. I know that as I read your post it really interested me. But at the same time, I didn't think to ask any questions because it looked like you were already providing info as it became available. Many of us have not tried tinkering yet, so we don't know what to ask anyway when it comes to circuits, etc. Keep up the good work and keep us posted.

Questions? You WANT Questions?? I gots LOTS of questions!!!

What model of AA are you using? (I know, not an extreme amount of difference between alkalines, but it does matter some)

How long does/did it go on this single AA?

AAA? C?? D???? button cell.. pair of potatoes.... scuffing the feet across the floor and charging a cap...........

What is the allowable input voltage range?
(I assume that this work well on a single nicad cell? 2 in series?)

When you gave the percentages above, are you measuring light intensity, battery voltage, battery capacity or what? (This may be a standard measurement here, but I am not following it.)

The light was still running at 57 hours, how is intensity holding up? Is the circuit holding current pretty steady?

Ideally a graph of input voltage versus output current would be very cool.

How many LEDs could this be scaled up to?

Could you share the schematic, coil manufacture instructions (please!) and/or the parts list - or is this going to be a chargeable item?

What frequency does the power converter switch at? I assume it would change with input voltage.

This may not be the greatest thing since sliced bread, but if we want to make our own light, why would we want someone else to slice our bread anyway? I for one am rather anxious to see it!!!

Thanks for sharing!!!

Hi!

This circuit sounds like this one I saw on a British website.

Here is the link to the circuit:
http://www.netcentral.co.uk/satcure/design/microtor.htm

This is the kit they have for sale:
http://www.netcentral.co.uk/satcure/hobby/eleckits.htm

I looked up the transistor they use:
http://www.zetex.com/pdf/thru.hole/ztx450.pdf

It seems to be a smallish power transistor.

I'm keen on trying to build this on my own out of my junkbox, so I'm wondering if I really need that particular transistor.

The web page says they sell a little ferrite bead in the kit and you wind a little transformer yourself. If I had the winding instructions, I might be able to try it out.

Anyways according to the web pages, this circuit is supposed to run a battery down to 0.75 volts. It is also supposed to put out 30 volts with no load so maybe it can drive a few LEDs in series.

If it all works as it is supposed to, it ought to be really nifty!

Eagerly awaiting more info...
Bert

Hope this post works because it is my first try.

Pics of IT

here are some pics of it, I don't know how well they will help but here they are.

Hello all just got back from vages, and well nothing has changed there.

I looked at the circuit on the link, and it looks the same to me! Even uses the same transistor! But I have found a very cheep repacement and the winner is (PN2222A) and even works better in my circuit, Now the bead is a much different matter! I've been in contact with Amiadon (Ferrite maker), and they are sending me out about 3 different sizes, I had the size in .mm but that don't help us americans much, I could hear the guy helping me on the phone scraching his head! hehe you can see the bead in the pics I took and how bright the lite is after 113 hours on the same AA battery.

The battery is nothing special just a energizer E91 AA that I had here at the house.

KenBar if there is anything I can do to help you let me know, I'm sorry you got a bunch of stuff that don't work, but I did say you can't get this stuff at RadioShack, they just don't have anything that will work that I know of, I can give all the web site info again of you need it, or more and better pics of it?

To test the circuits I use a bread board first and connect up everthing and then make it up!

Ok Forrest I'll try and answer all your questions .

As far as I know you can use any kind of power source I haven't tested it above 1.5V yet but think you can use up to 3V or two AA batterys.

Light intensity; well I don't have a light metter I was using my eyes to get the totals I should have said that.

As far as how many LED's this could be used to power? I think only one! but more testing will give the answer on that one.

the schematic is at that web address in UK already given but the info about the bead and how many turns of what kind of wire is left out I'm working on that now I know the size of the bead in metric but don't know how to convert it. I'm getting 3 different sized sent to me asap, and should be here next week.

What frequency does the power converter switch at? hehehe I don't know sorry, but if I did i could have made a better one I think.

I must say that when I got home I though that it would be dead, but it's still going and it's not very bright but IT'S STILL GOING! does anyone know how long a task lite will run if left on?

I am currently designing one (with some help from someone who knows this sorta stuff) for my project box. Similar to that design. It's just running the numbers and testing it before success. Basically all I am going to use is a variable resistors, mosfet, resistors, timer and drop it in the box.

Pretty cool stuff (the links above).

New to the board, but loving it already!

I'm only slightly electronically inclined but...
Does it HAVE to be a ferrite loop or would a simple iron core transformer work? You could cut a small piece of a nail and wind it with both "sides" of the tranformer.

If there is a simple explanation for why this won't work, please let me (us all) know.

If it involve great technical detail, I won't get it anyway.


Gadget

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Gadget:
New to the board, but loving it already!

I'm only slightly electronically inclined but...
Does it HAVE to be a ferrite loop or would a simple iron core transformer work? You could cut a small piece of a nail and wind it with both "sides" of the tranformer.

If there is a simple explanation for why this won't work, please let me (us all) know.

<HR></BLOCKQUOTE>

For high frequency oscillators and inverters, you need the powdered ferrite core.

The magnetic field in a solid or laminated iron core can't desaturate enough between pulses or cycles, so you lose a LOT of power. This is the simple explanation.

Someone else will have to come in here should you require a more detailed explanation of what happens inside a solid core transformer at high frequency.
But suffice it to say it ain't nice.

http://ledmuseum.home.att.net

BW- That`s the same place I got mine from.

It showed up today, I havn`t built it yet but I get the day off so I`ll set to work on it later. The nice thing is that it comes with a 5600mcd white led, but otherwise it is quite simply done. The keyfob case it comes with is a garage door-closer type with the LED`s hole quite roughly made, and the copper clad PCB has been "etched" with a Dremel tool or similar, just grooves cut to make the tracks. And the arrangement for the "switch" and button-battery holder setup is crude but overall it`s a nice little circuit and just crying out to be experimented on and built into something a little more durable.
Pictures will follow soon.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>For high frequency oscillators and inverters, you need the powdered ferrite core.

The magnetic field in a solid or laminated iron core can't desaturate enough between pulses or cycles, so you lose a LOT of power. This is the simple explanation.<HR></BLOCKQUOTE>

This is good enough explanation for me, thanks.

Does it have to be a closed loop or would a ferrite "stick" do the same job?

Gadget

Well I finished it, and always a great thing after building something myself- it worked first time !
And here it is...

<center>

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It does look very much like a car alarm remote but works quite well. With the white 5600mcd led in there it`s dissapointingly dim though- I don`t know what sort of current it`s pulling cos my bench meter`s gone funny but I`ll measure it before long. I do know the frequency though (that meter is OK) which is about 80KHz.

In the following picture of its beam you`d have thought I broke into the LED museum overnight and stole Craig`s test target, but don`t worry Mr Johnson, this is not the case. I produced my own target using the same specification so on this board (or anywhere else for that matter) when I wanted to show beam shapes, sizes, etc, I could use it and those numerous viewers also familiar with the Punishment Zone would have a fairly accurate reference- it seems to work doesn`t it?
Anyway...here is the keyfob light next to a white Photon-II with nice new Lithiums in...

<center></center>

It`s the barely visible one on the right. I`ll try some different leds in it soon, perhaps a Toshiba yellow 8 degree one- since that needs less voltage to light brightly it may perform better. There`s one here somewhere.....

An interesting little project but not really anything to rival existing LED flashlights. The circuit though, has potential. I`m sure I could improve on this construction making it much smaller and more robust (you wouldn`t want to drop this for fear of its life!), and performance, there`s some fun to be had on future days off for sure!

Ron- the keyfob case came supplied with the kit I bought but if you have a busted car alarm/garage door tramsmitter, that would probably work- that`s the original intended use for that case. You pay your £10 plus P+P (US$15, but UK/Europe only , not sure if he ships to the States) and get all the parts needed including white LED, readilly cut metal parts, PCB and case plus full assembly instructions. The only thing you don`t get is the solder to put it all together with! It runs on a lone 1.5v Mercuric Oxide button cell, I believe a 625A, well that`s what it said on the card it came on anyway. It would certainly run on 1AA though but since an AA can give more power than one of those little button cells it may be brighter. Meddling with the resistor (affects the osclillation frequency) may improve its performance too but that`s another day.
I don`t know, compared to a white Infinity, whether it`s brighter or dimmer but I`ll know soon enough (4 of them heading this way!!) and post the results of course!

"Your results may vary"

I always use HTML email messages by default (well I`m that sort of person!) and they reached him just fine (maybe it depends on what mail server you are on?), he replied both times. I agree- nice guy and I do like that "trust system" of his for payment after he ships the goods (UK/western europe).
Plain brown envelopes work fine for me- I have sent cash that way overseas numerous times and it was fine. Incidentally I usually use 1 GBP = 1.50 US$ cos it does vary whether you`re buying or selling (át least at my bank it does).

Chris,

Very cool little kit.

For the tinkerers of the group, including myself, what is the turn count on the ferrite bead and what size is it? Everything else in the circuit is basic stuff even I understand...

I'd be very interested in "bulking up" the circuit just a bit to handle D cells.


Gadget

Nice work. That's a neat little case you packaged it in. What is it from?

Too bad the light's so dim. Looks like it might be on the level of the Infinity Task Light. Which would make sense since that too is a 1AA light.