ultrabrightLED flashlight

[Someone Electro]

This circuit will be a bit big to fit in an flashlight

Mostly the inductor.

 

[audioguru]

The Silicon Chip project is made to fit in a flashlight.

 

[zachtheterrible]

Wow, this is going to be my first surface mnt project!

Are there any really good tutorials that someone can point me to for this? I'd really like to learn about it before I go and fry the tiny transistors and what not.

I believe i have all the equipment necesarry: soldering tips, and a temperature controlled soldering iron (a really nice one that i got for free :lol: ).

I also have some evaluation boards, where they provide you with a bunch of chips and SMT stuff. So I can practice on those first.

 

[williB]

Zach , google 3021 buck puck
their Model #2009-H looks promising..

 

[zachtheterrible]

willi, i cant say im all too enthusiastic about that driver. For one thing, the datasheet doesn't give any cold hard facts. Its more geared to the consumer who doesn't know anything about electronics.

It did say though that it mimics an incandescent bulb in that it gets dimmer and dimmer. What's the point of that? The only reason I'm using a DC-DC converter/regulator (i dunno exactly what to call it) is so that my LED remains at a consistent brightness.

If I want to mimic an incandesant bulb, why don't I just put a resistor in series and direct drive it? :lol:

Besides, i already ordered my parts :lol:

 

[audioguru]

It did say though that it mimics an incandescent bulb in that it gets dimmer and dimmer. What's the point of that?

Their marketing dept turned its technical fault into a "feature".

 

[Roff]

It did say though that it mimics an incandescent bulb in that it gets dimmer and dimmer.

Zach, I couldn't find a statement to that effect. Where is it?

 

[audioguru]

Hi Ron,
Google 3021 buck puck.
Their Model #2009-H driver dims the LED as the battery voltage drops. :lol:

 

[Roff]

Hi Ron,
Google 3021 buck puck.
Their Model #2009-H driver dims the LED as the battery voltage drops. :lol:

Ah, OK. I stupidly had gone to the datasheet of the 3021 buck puck - since that is what I was searching for. I see that it costs a lot more, and requires a higher voltage supply. Good reasons for looking at the 2009-H.

 

[zachtheterrible]

Their marketing dept turned its technical fault into a "feature".

HAAA HAA HA!! :lol:

 

[Oznog]

Their marketing dept turned its technical fault into a "feature".

HAAA HAA HA!! :lol:

Luxeon had an LED product with that problem and decided to call it "moonlight mode".

 

[williB]

Zach , how is the led project going ?
today i bought a Light that uses a 1 W Luxeon LED , picked it up at Lowe's

**broken link removed**
the one i bought uses three 1.5V AAA batteries
It's really really bright..
i havnt done any tests on it yet , but it doesnt appear to blink...

 

[Dr.EM]

These LED torches are definately better than bulb types, but they will still be let down by poor battery technology. My old maglite, I put a couple of AA Duracell make batteries in there and they leaked, after just a few months. I guess one of them must have been faulty. When I tried to use it, I found it didn't work, and it was nearly impossible to open the end cap (a vice and big pair of pliers did it eventually) never worked after that though. Are lithium batteries more suitable?

 

[audioguru]

Hi Dr. EM,
Energizer make some 1.5V AA size lithium battery cells that are designed to be used in high-current digital cameras. They hold their voltage up very well when discharging, have a very high capacity and last for many years in storage. They also weigh less than alkalines. :lol:

 

[Nigel Goodwin]

My old maglite, I put a couple of AA Duracell make batteries in there and they leaked, after just a few months.

It's very uncommon for Duracells to leak, I wonder if the torch had been left on accidently?.

A couple of VERY important points with batteries:

1) NEVER EVER MIX OLD AND NEW BATTERIES

2) NEVER EVER MIX BATTERIES OF DIFFERENT TYPE OR MAKES

Doing either of those will almost certainly result in battery leakage, and even if you keep a really close eye on them?, will result in drastically shortened battery life.

It's also advisable to remove batteries from items when not in use, you won't believe the numbers of products I see destroyed by leaking batteries!.

 

[eblc1388]

Worst culprit, leaking NiCd battery.

My laptop was ruined when I left it unused for a year. The NiCd battery CMOS backup is of the type that soldered to the motherboard, can't remove it. The leaked electrolyte destroyed the fine tracks to and under surface mounted ICs. I washed the board in water but nothing would help.

 

[Nigel Goodwin]

Worst culprit, leaking NiCd battery.

My laptop was ruined when I left it unused for a year. The NiCd battery CMOS backup is of the type that soldered to the motherboard, can't remove it. The leaked electrolyte destroyed the fine tracks to and under surface mounted ICs. I washed the board in water but nothing would help.

Yes, NiCd's are bad! - but it's not as liquid as the corrosive from non-rechargables. I've got an old Korg musical keyboard I was given, and the backup NiCd battery in that has leaked and damaged the processor board.

It's usually recommended to remove the charging resistor and replace the NiCd with a lithium cell.

 

[williB]

Here are the stats on the light .
with three AAA batteries, it draws 225 mA..
And at the LED it reads 3.36 V

 

[audioguru]

Hi Willi,
That's a nice LED light. :lol:
But it isn't 1W!
Maybe your current meter dropped too much voltage.
Let us know if it dims as the battery runs down.

225mA is a very high current for tiny AAA cells. Get some good battery cells for it. Here is the difference between Energizer's Alkaline AAA and their Lithium AAA cells:

 

[zachtheterrible]

Hey willi, the LED project is going terribly! Q1 keeps on shorting out the positive and negative rails for some reason. Its on all the time, instead of only being on in pulses. I have NO idea whats going on with the bloody thing! Its also oscillating @ 370khz! Its only supposed to work @ around 200khz.

since its already on a PCB, its very hard to experiment with it and change out components. I just ordered the same parts again from mouser. Im going to put each one on a PCB, then run wires off the PCB so that I can put it in a breadboard and experiment.

I am not giving up on this project! It will be such a great thing when it works. Just imagine a flashlight that runs for several days at the same brightness, even when the voltage drops to 1v!

Ill have to drop by lowes and check that thing out.