2 AAA Ni-MH or 1 Li-Po adjustable LASER driver

sweet! free shipping on everything
i just ordered a Romisen 30mW green and some cr123's
i still need to find a case for my new 3410 powered burner, oh and i tried it, it does work from 2 ni-mh's, for some reason the first one i made didn't, maybe i damaged the chip when i powered it with no load...
oh and i made another heatsink for the aixis module, this one wraps around the module head and has way better thermal conductivity, you where right about that before. will post pics soon

That's great! Can't wait to see the pics. I want to do something similiar, so any ideas are welcome.

BTW, is this the first time you heard of DealExtreme? I love the free shipping as well. I can order stuff whenever i like, without the need to wait to combine several items for lower shipping costs..


If you will be using unprotected Li-Pos, i would highly recommend making a simple low battery alarm.

I use a special red LED, that has a built in IC, which turns it on, when the voltage drops below 2.7V.. It's perfect for one Li-Po, or combined with a 3V Zener, for two Li-Po cells.

I buy them at Conrad.. Don't know, if they have them somewhere else.. But if you need them, i could buy some for you, the next time i go to Austria.


You might also consider putting a 3.3V zener in reverse over the 3410 output, to prevent such no-load accidents..

Thanks for sharing this, I've been reading through all the DC/DC threads, and I think this is a great solution. Nice work everyone.

well i found a case for it
i have it running off a single ipod nano (1st gen) lipo, probably about 300mAh.
the laser is in the home made heatsink i mentioned before, which is wedged in the can and insulated from the can with electrical tape. this probably allows a bit of heat transfer to the body. the can also has the bounus of being a sorta faraday cage, stopping any uhf interference.
i was going to run it off 2 AAA's, but they didn't quite fit, without modifying the heatsink i made.

and igorT, what is that led called from conrad? like the cat number. i can't seem to find it

Hehe, nice job!

I see your signature is updated..

And you said you were getting sick of lasers...



About the Warning LED, i'll have to check.. I'll let you know, as soon as i find it.

Woop...

I just found the number of that LED.. It is #185787

I buy them in Austria for 1.73€ for one or 1.56€ for 10. They are probably a little cheaper from Germany directly.


Do you have Conrad in OZ? Or do you intend to order internationally? If the shipping turns out to cost more than the LEDs, let me know, and i can buy them for you and send them via normal airmail.



Oh, the product description says 2.4V and the detailed description says 2.3V, but from my measurements, they turn on closer to 2.6 - 2.7V.. This is a little close to the lowest safe Li-Po voltage, so i add a diode with a low voltage drop, so i get the warning a little sooner and know it's going empty. For two Li-Pos i use a 3.3V Zener.


The diode is a 5mm package, but i usually cut the top away with a dremel, so it's flat and uses less space.  For the laser, i will also dremel it away from the sides, to make it thinner. I once killed two, by cutting off a little too much from the top.

Otherwise, you just connect it directly across the batteries, in parallel with the circuit, and it turns on, when the voltage drops too low. In standby it only consumes 5uA, so it can even be connected to the batteries all the time.


By itself or with a Zener it turns on very bright, but with regular diodes it is a little dimmer, as their voltage drop varies with the current, so the diode itself influences it a little. But it's still very usefull and recommended for unprotected batteries.

when i search that number it says Unfortunately, 'the desired product can not be displayed.'
I only really wanted some more info on it, and its name... i was hoping to search for it locally

Yeah, the international site doesn't display certain products..

Go to www.conrad.at and type in the number into the little window. Only the first six numbers, leave the smaller window empty.

Unfortunatelly, the text will be german, and there is no datasheet.

I'll translate what it says:

LED with Low-Bat Warning

The "intelligent" LED works as a voltage monitor with an optical alarm display.
The integrated CMOS chip turns the LED on, when the voltage drops approximatelly to 2.3V. The standby current is only 5uA, so the batteries don't get discharged.


That's all the info there is. No manufacturer, no nothing. And i was never able to find them anywhere else.

I use them in all our battery powered custom made devices, that we develope and build. I print a label, with everything black but the text, and cut a square opening under the Lo.Bat letters. Then i just put this LED behind it, so the letters light up, when the battery is empty.


As i said, i have a bunch of these, so if you need some, just let me know..

Ok. thanks for that.
those led's would be very useful, i was thinking of also using then with my model planes to show when the lipo is getting low. one across each cell would also show if the pack is unbalanced
it would be great if you could send a few. maybe 5. I would pay you for it

woop said:

Ok. thanks for that.
those led's would be very useful, i was thinking of also using then with my model planes to show when the lipo is getting low. one across each cell  would also show if the pack is unbalanced
it would be great if you could send a few. maybe 5. I would pay you for it

Click to expand...

Conrad also sells "special" Li-Po protectors, but they are noting more than one of these LEDs with a diode to drop the voltage depending on the number of cells. But those cost more.

If you use one for each cell, just make sure, you use two, that turn on at the same voltage. They may vary a little.


Need to check how many i have here, otherwise i'm going to Austria again this week, so i'll pick up some more. I'll let you know when i find them. They are currently MIA.

I changed the case for my burner. now its in a film canister.
and there is room left over.
i prefer this to the mint can because the laser housing can't short out to gnd. and it is easier to have the lens mounted outside of the container a bit for easy adjustment

That's small! Show some pics...


Oh, and PM me with your address, so that i can send those LEDs to you..

hey igort want to send me some LEDS? ill pay for them i cant find them either

I can, but it won't be very soon. I'll have to order them, and then go to Austria to get them. In the worst case it can take two weeks, before i can send them.


PM me with the number you want, so i can call Conrad, and order them ahead of time. Otherwise it'll take even longer.
Also send me your address, so i can check the shipping costs.