Brads Electronic Projects Forum

I went through hurricane season last summer and I remember being in the hardware store and there were probably at least six people in line at any one time looking at sump pumps. Most stores were sold out of flashlights for a week or two except for the most expensive flashlights.

We lost power but we were fortunate that we were only without power for about six hours. Our area has a limit on how much rain it can accept. Some people easily lost power for half a week or more. We have flashlights with the lantern batteries and I have some flashlights that take double A batteries.

I began to think about our needs and when the flashlights were back in stock, I bought a few more flashlights. Since we have rechargeable batteries and (double AA) batteries are in abundance, I bought a couple more flashlights that use double A batteries and one of them has an LED in it. I have two other LED flashlights with multiple LEDs in them. The problem is that they aren't bright enough and the LED flashlight says it will operate for about seven hours.

What I would like to do is have a flashlight that can switch from the number of LEDs it uses from low to high and I would also like to have this flashlight work with a 6 volt lantern battery. I want it to be able to provide a lot of light and also be able to last a long time because LEDs use less electricity than regular bulbs. I want to be able to switch from low to high brightness and also be an energy saver in case we need a flashlight for a couple of days.

The kind of flashlight we have to convert (in abundance) is here:

http://www.lowes.com/pd_355538-346-5109 ... facetInfo=

Or should I just buy this flashlight:
http://www.walmart.com/ip/Dorcy-13-LED- ... y/17351562

Some of these flashlights are only 40 lumens even though they use 19 LEDs:
http://www.walmart.com/ip/Hoffco-08-N10 ... m/16480853

Should I bother with this project or just go out and spend the money on a good flashlight? Can I do this with some resistors or do I also need to use a chip? If a good design is created, it could radically help others and it could also be a best seller. I was hoping for 100 lumens in a flashlight.

This flashlight has 52 LEDs:
http://www.walmart.com/ip/Trademark-Glo ... t/17155395

I found these other projects on the web that are sort of like what I want to do so they may give me ideas.

Lantern Torch LED Conversion
http://www.instructables.com/id/Lantern ... onversion/

How to Make an LED Flashlight
http://www.popsci.com/flashlight

Honorable mention:

The universal multicolour torch (flashlight)
http://www.instructables.com/id/The-uni ... lashlight/

This is the other flashlight that may be a candidate although I see less of them at the store:

http://www.amazon.com/Rayovac-EVBFL6V-B ... 78&sr=1-23

I may check out 1 Watt Leds.

What I need to know is how many would fit on a circular cut circuit board. I think I would put a 1 Watt Led in the middle and a lot of high power white or blue leds like these:

http://www.adafruit.com/products/301
http://www.sparkfun.com/products/531

I'm not really sold over this Triple output high power led:
http://www.sparkfun.com/products/8718

I suppose I need to know which functions (how many leds to light at once) and then come up with a wiring scheme.

You should recreate the 500 LED flashlight that some guy made on youtube.

Just do a search for 500 led flashlight on youtube.

I don't really want to build something that big and complicated.

Someone suggested I ask over at the Candle Powered Forums and I'm learning more about flashlights than I wanted to know. All I want to know is how to hack a flashlight using brains and not brawn but they do talk about some really nice looking flashlights.

If I had $260 to spend, I would probably get this flashlight but it is probably not something you can use in public:

http://www.amazon.com/NiteCore-TM11-Mon ... 116&sr=8-1

The review is here:
http://nitecore.com/goods_detail.php?id=28

They take this flashlight outside at 9:03.



It is all nice but it isn't what I want to do. I can see myself spending some time on this when I can just go out and buy some flashlights.

This whole thing has opened up a can of worms for me. I'm looking at the Xeno E03 and Fenix E01. I'm looking at the 18650 battery charger and batteries that can last 10 years like the CR123A. There is also a P60 LED dropin that retrofits certain flashlights so I'm sidetracted and I can see myself spending a few months on this.

It's amazing how far LED technology has advanced over the years.

I was in the store tonight and apparently they changed the flashlight from incandescent to LED. The flashlight here holds three LEDs and I don't think it is any better than incandescent.

I have already bought 25 white super bright 5 mm leds. So I'm not sure that changing the flashlight over will be much of a hack and since the flashlight already has holes for three and I might not need to add a resistor.

How did you go with this Chuck?

brad wrote:How did you go with this Chuck?

I bought a pack of 25 super bright leds. I'm going to breadboard a few of them and power them with a six volt lantern battery.

I've always wondered why Christmas lights only work one year and then don't work the next year. Someone said the strings of light from China weren't meant to work with high voltage over a long period of time. I don't want to power them so they burn out too quickly but I want a decent light.

Then I have to open the lantern flashlights and decide which one would best work with being modified and I have to devise a system.

I hate to ruin a perfectly good flashlight so I have to choose between the LED lantern flashlight and the regular incandescent flashlight. If I choose the incandescent, I may cut a protoboard and fit it inside one of the flashlights.

Dont forget to post photo's!

brad wrote:Dont forget to post photo's!

I learned that if I don't add a resistor, the high power LEDs will burn out and if I do add a resistor, the resistor should get hot. The LEDs should be run with PWM or one of these chips:

viewtopic.php?f=20&p=3279&sid=696c5cc96 ... cf0d#p3279

I don't know enough right now to get this project to work so I have to put it aside for now.

Chuckt wrote:I have already bought 25 white super bright 5 mm leds. So I'm not sure that changing the flashlight over will be much of a hack and since the flashlight already has holes for three and I might not need to add a resistor.

Chuckt let me get this right?, so you have a flashlight that already has 5mm Leds in it and you want to put some bright 5mm leds in it instead? what type of bright 5mm leds are they?.

I hope I bought the right ones and they also have them in red but I wanted to use something like this:

LED - Super Bright White

http://www.sparkfun.com/products/531

Super Bright Blue 5mm LED (25 pack)

http://www.adafruit.com/products/301

I think the clear white ones would have made a brighter light than blue?, but its user preference and needs.
When buying LEDs its always a good idea to look out for the millicandela (mcd), especially if you want bright LEDs, the higher the mcd value then the higher the brightness of the LED.

I would certainly use a Resistor with any LED, too much current will burn out the LED or the LED could even explode!.
You shouldn't need anything else to drive these LEDs other than power supply (battery) and some Resistors, and poss a switch to turn them on and off..

How many LEDs are you wanting to put into the flashlight?

bitfogav wrote:How many LEDs are you wanting to put into the flashlight?

I have ordered the wrong LEDs. I bought IR leds instead of the right ones. I would have to re-order.

I looked at both flashlights and I really can't add more LEDs to either flashlight without ruining the reflectors which are important to throw the light. The Eveready flashlight with LEDs has a small circuit board and resistor in there and it is pretty much a sealed unit that is smaller than 2 inches (about) and I would have to break it. It is pretty much a throw away unit once the LEDs go bad. When it goes bad, I might have less reservations to break it to change it.

It would be nice if I could find an incandescent socket to LED conversion part but it may be unlikely.

I might have better results taking the incandescent out of one of these small $1.50 pen flashlights and soldering an LED with resistor in there.

I'm going to look at other options and may look at the one flashlight in the instructables to find a better flashlight to convert.

It would be great for a night vision camera though!