Modding my first light: FourSevens Preon

Hello all,

I'm trying source the parts to mod my Foursevens Preon with a 2 aaa body. This is what I'm thinking:

- 12mm FET driver from MNT Electronics (http://www.mtnelectronics.com/index.php?route=product/product&path=67_117&product_id=493 )
- gumpydrv
- No LVP

- 8mm MCPCB ( http://www.illumn.com/leds-drivers-optics-mcpcbs/led-mcpcbs/8mm-xp-g-mcpcb.html )

- XP-G2 S3 3D ( http://www.mtnelectronics.com/index.php?route=product/product&path=60_62&product_id=156 )


I have no idea if this will make a usable light, any advice is appreciated.

Thanks!

Ooh. Let me know if you end up selling the stock circuit. I'm in need of one!

Okay. Advice to follow.

Okay, unless things have changed, the Preon has a battery contact board wired to a circuit, wired to the LED board.

carefully pry off the battery board, be very careful or you could rip the wires off or break the inductor. I know this from experience!

Desolder the LED board and contact board and you can replace the circuit.

Ask Richard at mtn electronics if the fet board fits the Preon pill. If so, sweet.

Guppydrv is great. Why not lvp?

You can buy an 8mm board but if you are reflowing anyway, why not use the stock board. It will fit better.

So, try the mod and sell me the stock circuit. Or post what Richard said and I may try to fix a dead maratac with a fet driver. It may need to be filed down to 10mm.

It all looks like this. Note the broken Inductor.

Thanks for the info. I want to run this light on 2 lithium primary cells so I did not think a lvp was needed. I'll give Richard a call tomorrow and see what he says, this board looks like the only think that size that will take above 1.5v so I really hope it works.

Here are the guts from my pill:

Hey Mike,

This is slightly off topic, but could this 12mm driver from MTN work in a Aleph set-up? I think this driver will make me want to build a Haiku...

Also do you know what the backside of the MNT driver looks like? I was hoping it would replace the battery board like the driver pictured:

I've never seen the driver. I think it looks like that. You will still need the contact board tho because of the way it fits the pill.

Ryan, good catch. Yes, it will likely fit a haiku pill.

Dang, I was thinking it would go in place of the contact board and be done. And if my mod is successful I'll send you my stock driver for the cost of shipping :thumbsup:

The contact board is usually "keyed" to fit into 2 notches in the pill. You could certainly file it to try.

Here is my reply from Mtn Electronics:

"It will, but the output will probably only be around 2A depending on the forward voltage of your particular LED and the amount of voltage sag. In short: yes, it will turn on and light up your LED, but the output may not be as much as you would like. The output will drop steadily as the batteries drain.
Guppydrv does have low voltage ramp down, so please let me know expressly in the checkout comments if you don't want low voltage protection. I'll change the resistors so it will be completely disabled."

2A at 3v with an XM-L2 seems like it would be plenty bright. I think I'm missing something here.

They are used to super pocket rockets on BLF . I think he had one of these in an aaa thrunite and had 600 lumens initially, which quickly dropped to 500 and heated up fast. He's likely thinking you want that. Fet drivers are designed for direct drive like power.

Oh and remember it will only work on 10440. No AAA.

Dang, I'll see how it works on 2 lithium primaries anyway. If the output is too low I'll switch to a 10440.

Might be a tad dim. It functions like direct drive.

Also. I didn't see the exact driver but other ones seem to need the contact board.

After looking at my options it looks like the stock driver is my best option. Plus it was easier to get back together than I thought!

I just gotta swap leds and put it back together [emoji1]

Ready for new emitter

I want to do this to my Preons, but I'm scared to start it myself. What I'd like is one modified with stock driver, for use with Ni-MH and alkalines (in emergencies only), a Nichia 219A or XP-L 4000k, and one with an XP-L and driver swap for use with 10440. What tools wouldiI need if I do decide to attempt this myself?

A soldering iron and snap ring pliers to remove the pill. That really all I've used so far.

Almost done, I reflowed a xm-l2 5000k onto the stock mcpcb and added a medium flood optic. I just need to clean up the edges of the optic and I'm done [emoji4]