what is up with all the resistors?

Hello to all.

I just wanted to ask if anyone has thought up a way to make a flashlight with LED's of course, that has a very small curcuit (a DC/DC converter) to supply the LED's with the proper ma-rating or whatever ma rating you want to set?

Not wanting to brag or anything but I have done just that! and you can input any voltage 3Vdc up to 40Vdc to my little curcuit, it has a low current dropout so the light just goes out when the batterys get too low, I'm by no means an expert when it comes to electronics but after getting hooked on this bbs and making many LED flashlights, I just wanted more and went looking for an answer!, I found one!.

I have made 4 flash lights. I have given them all to my friends at work! and they are being tested to the fullest! and So far so good

All though I'm not ready to make my little circuit known to every-one, I want to test it more to see if I'm right about it and dont want to look bad!

I would just like to know if anyone else is making or using anything like this? please let me know.

Ghost Man - Can't wait to see what you've done. Hope you'll post the schematics so we can play around with the concept too. Do you have a PALlite? They are circuit based to allow the use of a 9V battery. They burn bright all the way down to about 6V if I remember right.

The resistor approach is fine. It's easy to do and works reasonably well. But since this whole LED thing is about getting the most light and runtime possible, circuit based lights are what really get my interest.

This sounds interesting. Let us know how it goes.

hehehe.

Does anyone know how to post Pics and stuff so they will be seen here?

I have a digital cam and can take some pics of what I have made, I like to make lights that have 3+ batterys they have good voltage output and last a long time!

go to www.photopoint.com
You can post pictures here for free and then link to them from here.

ok here are two pics of on of my light.

see if this works?

web page

Did the light case come from Sears?

I got the lite from sears, it's cool looking and takes 4AA, it has a battery power level meter on the side, don't know how well it work's.

I have two White LED's in it that I got from BG Mirco, there ok, but if anyone know's where I can get better ones I would like to know?. There both running at 40ma, I'm not sure what the max ma on this circuit is, but I have had it up to 200+ma on one very old red LED and it burnt out. I'm goint to test this light in the pics tonight, I turned it on at 7:30pm pst, my time and will leave it on to see how it does.

The ones I handed out at work for my friends to use are almost the same! some are at a little higher ma rating and others lower, just to see what would happen, the guys think I'm crazy but they love the lights because you can see wire color very well with them.

I will post the circuit soon when I get it scaned, it's very simple and very easy to build only 4 to 5 parts (With out the LED's) getting the parts are the thing, I had to order everything the IC you can't get at radioshack. and maybe we all could improve the thing to make it better? there is always a better way of doing things

<img src=http://www.sonicunderground.net/shq/smilies/jawdrop.gif>

axolotis,
How the *x)(+* did you make that
sign with the looong tongue??

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by videocal:
axolotis,
How the *x)(+* did you make that
sign with the looong tongue??<HR></BLOCKQUOTE>

I just linked it from

http://www.sonicunderground.net/shq/smilies



They have a ton of goodies there like:

<img src=http://www.sonicunderground.net/shq/smilies/cursing.gif> - I burned my thumb with the soldering gun!

<img src=http://www.sonicunderground.net/shq/smilies/insane.gif> - I stared directly into my 23 LED Box

<img src=http://www.sonicunderground.net/shq/smilies/nono.gif> - Honey.. What did I do now??


Oh well, you get the picture(s)

lots of info on driving (multiple) led's


web page
web page

Very nice info! thanks

But I must say that the circuit I make is much smaller and I think better! but I will try these and see there results.

work has been extra busy this week and I've no time to post my circuit, I need to get it scaned or find a circuit maker program that will make a jpg file or somthing like that.

I'm printing like a mad man and will read all this stuff tonight.

Thanks again.

Ok I Will post the Circuit and a parts list tonight it's very close to the one that was on the last web link, it uses a LM334, a pnp transistor and one cap and one resistor.

I just need a little time to put it all together.

I dug up a few more links for do-it-yourselfers

LED Caving Lamp Development & Use

battery comparisons

good place to buy led's

The Brightest and Most Efficient LEDs and where to get them


OddOne's site

Has anyone used one of OddOne's White LED Modules? I am curious how bright they are.

Well here is the link to the Circuit

web page

I have one more trick up my sleeve, I have a friend in London, that told me that he knows a guy that will sell my a circuit for a (as he called it) Micro LED SUPER BRIGHT TORCH! that only take's one 1.5 cell, and work about 41 hours, the battery can be almost dead and it will still shine very bright Sound like CMG?) it is costing me some big Bucks! or Pounds hehehe, but it's on it's way and should be here in about 3 weeks or so.

Well when I get it if anyone want's to see it just let me know!

And if you have any questions about the Circuit in the link I can help you! I'm not sure how many LED's it will power, but i've had it up to about 200+ ma. and think I can get it highter.

The flash light that I started testing the other night finally craped out, on the 4AA batterys it was very bright for 33hours, and went to 50%bright for 5 hours then 4 hours more to all dead. Not bad

Thanks for posting that!

One question- do you know if the output can be adjusted, eg by changing the resistor value, perhaps even fitting a variable one? Then it could be fiddled with initially to get the ideal brightness/current draw for whatever setup of leds you used, and then just replaced with an equivalent value fixed one? Or left variable so as the batteries die it can be cranked up, or turned down sometimes to save power, etc?

I may have to build one myself and find out....

(and yes, I for one would be interested in seeing the inverter setup, hope it doesn`t involve any exotic parts!)

Yes you can change the output with the resistor, the one in the pic is 1.6 ohm, if you used two of them in parallel, you get 80ma for two LED's and if you add another 1.6 you get 120ma's for 3 LED's. see how this works?

Hi,

I've been interested in this circuit for a while myself but had a difficult time finding a source for the LM334. Where are you buying yours? Do they have a reasonable minimum order requirement? Please let me know. Thanks.

Mark

Hi,

I've been interested in this circuit for a while myself but had a difficult time finding a source for the LM334. Where are you buying yours? Do they have a reasonable minimum order requirement? Please let me know. Thanks.

Mark