Birthday Mag - 6AA>2D, 40-1200mA CC (+ 6D, 0-600mA)

[TigerhawkT3]

For a friend's 21st birthday, I gave him a "gift certificate" for a medium-sized flashlight project. This is what he chose.

-2D Mag
-Stock reflector, cam cut off
-DHS heatsink
-SSC P4
-Two KD 3AA>2D adapters
-6AA
-LM317T
-25Ω pot
-Two 0.47Ω resistors

Video. Hopefully I'll get a couple more when/if I get to give him the light tonight.

Full dev thread.

Pics of the process:

 

[TigerhawkT3]

Re: Birthday Mag - 6AA>2D, 40-1200mA CC

I gave my friend his flashlight! I think he really likes it.

Video of his reaction here.

 

[2xTrinity]

Re: Birthday Mag - 6AA>2D, 40-1200mA CC

Clever idea to pack the driver into the tailcap -- as it is, that's wasted space when not used to store a spare incan lamp.

You should try to get a hold of a SSC P7 4-Die LED, and do a similar build using 2 Kaidomain D-Cells.

 

[TigerhawkT3]

Re: Birthday Mag - 6AA>2D, 40-1200mA CC

Yeah, the tailcap JUST BARELY fit all the components. :sweat: The pot and pair of resistors that are used as sense resistors really added up.

The weirdness of the P7 is, of course, the fact that the dice are in parallel. Still, it could be doable, using multiple LM317Ts and no extra resistors. A package with series dice, like an Ostar, would be much simpler. The only change would be using 14500s instead of alks.

I'm planning a build in a 6D, with a different pot and no extra resistors, with the entire driver replacing the stock switch assembly. Figuring out a ground path will be interesting.

 

[MorePower]

Re: Birthday Mag - 6AA>2D, 40-1200mA CC

I had a post all typed up and then the forum died on me. Oh well.

Anyway, I've got a few questions, if you wouldn't mind helping me out.

1. Are the legs on the LM317 in the 4th picture Adjust, Vout, Vin, from left to right?

2. Is Vin connected to the positive battery terminal? I think that's why you needed to reverse the AA cells in the adapters, right?

Any input is appreciated; I have Friday off and would like to try to throw one of these together before the weekend if I can.

 

[TigerhawkT3]

Re: Birthday Mag - 6AA>2D, 40-1200mA CC

1. Yes, it's Adjust, Out, In. Looking at schematics online, you'd think it was In, Adjust, Out, but it's NOT. Follow the little diagram with the numbered pins (1, 2, and 3) on the back of the LM317T's RS box, and you'll be fine.

2. Yes, and yes. Notice that the bottom of the battery, the +ve terminal, doesn't connect directly to the spring. It touches the little soldered nub in the center of the plastic disc, which is the LM317T's In. The spring is connected to the LM317T's Adjust.

Note that, because of the backwards batteries, the ground tab in the Mag switch should connect to LED+, and the connection hiding in the switch should connect to LED-.

If you really want to, you can skip the extra 0.47Ω resistors and make sure not to turn the power all the way up. Since I was planning on giving mine away, though, I couldn't rely on that.

I hope to do the 6D build today. Happy modding!

 

[MorePower]

Re: Birthday Mag - 6AA>2D, 40-1200mA CC

Thanks.

I plan on using a single 1.5 ohm resistor rather than 2x 0.47 ohm in series. Max current will be limited to ~800-850mA, but that's fine with me. It'll save a bit of space in the tailcap, too, so that should make cramming everything in there a bit easier.

 

[FILIPPO]

Re: Birthday Mag - 6AA>2D, 40-1200mA CC

wow good work!

and do not forget: my birthday is on the 13th of November....

 

[TigerhawkT3]

Re: Birthday Mag - 6AA>2D, 40-1200mA CC

I've made a 6D Mag with this driver and LE. The LM317T and the pot (a different one, from Fry's) are actually where the stock switch usually resides. The pot goes from 2-10kΩ, audio taper, so max output is 600mA, and there's a BEAUTIFUL low range. I can get the yellow phosphor coating to ramp up to a light grey color, and then make the reflector look like it's simply painted a light grey, all the way up to a blinding 600mA. There's not much control at the high end, but there's lots of room at the low end. It's pretty nifty. I've been too lazy to get a video up, but it'll happen eventually.

Here's what the driver/switch assy looks like:

And here's the exterior switch area:

 

[rizky_p]

You both talks like a true flashaholic. I bet you wouldnt notice a nude girl passes by...

Could you post a schematic on how the driver put together?

Thanks.

 

[TigerhawkT3]

You both talks like a true flashaholic. I bet you wouldnt notice a nude girl passes by...

Could you post a schematic on how the driver put together?

Thanks.

I bet I would. And what if it was dark? Flashlights would be very handy in a situation like that. :laughing:

Here's a photo schematic. The sense resistor can be an ordinary resistor or a pot/rheostat. Current is determined by I = 1.25V/R. Make sure it has a high enough wattage rating to handle 1.25V multiplied by whatever current you choose. You'll also need a battery a couple volts over your emitters' total Vf.

 

[rizky_p]

I bet I would. And what if it was dark? Flashlights would be very handy in a situation like that. :laughing:

True :naughty:

Here's a photo schematic. The sense resistor can be an ordinary resistor or a pot/rheostat. Current is determined by I = 1.25V/R. Make sure it has a high enough wattage rating to handle 1.25V multiplied by whatever current you choose. You'll also need a battery a couple volts over your emitters' total Vf.

Thanks for the schematics

 

[flashaholic]

Just asking, where can i get battery packs like those, i'd like a pair to turn my 2d mag into a 6a mag and just use the 6d bulb

 

[horizonseeker]

you get them here:

http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=3294

 

[Swagg]

This may be a silly question but I'm a noob, will those battery trays work with a 2D ROP mod?

 

[TigerhawkT3]

This may be a silly question but I'm a noob, will those battery trays work with a 2D ROP mod?

Eh... Well, maybe for the ROP low bulb, but definitely not for the high bulb. The thing is, they can't handle more than 2A or so without melting and falling apart, due to their high resistance. A good carrier (modamag, fivemega, etc.) or battery pack (cheapbatterypacks.com, LuxLuthor) will give much better output in these high-current applications. However, they're adequate for many LED setups drawing less than an amp or so (this mod draws 1.2A).

 

[FILIPPO]

wow good work!
as usual....:twothumbs

 

[Caligvla]

Where did you get those 2 AA to 1 D converters?

 

[TigerhawkT3]

They're the 3AA>1D converters on kaidomain, as mentioned in horizonseeker's post above (post 14).

 

[TigerhawkT3]

Update: it broke.

He said the head started to get really hot, but he kept on using it. Then it turned a deep blue, and he was pleased at the pretty color. Then it stopped working.

I have a feeling he never ran it at anything less than the full 1.2A (which makes me wonder why I went to the trouble of making it dimmable in the first place :laughing: ). Fortunately, all I have to do is replace the P4 and tell him how to avoid a repeat of this.