What did you mod today?

DQG Hobi MT-G2

Well according to that calculator the beam size and the aperture are what matters. The beam size is determined in part by the emitter size (they are roughly proportional).

I agree with what you say, but I think the calculator is not completely right, for the reason I explained above. Imagine you have your lens, but you can switch between two different sized emitters. The two emitters will make different sized beams (measured at whatever distance), and so that calculator would predict different “divergence distance behind aperture” for each emitter. I am arguing that this is not accurate; they should have the same “divergence distance behind aperture”.

My measurements showed that this distance is the same for different sized emitters, and I think this makes sense. Imagine having one emitter, then putting another emitter right next to it to effectively double its size (in one dimension). Nothing has physically changed about that first emitter, but the calculator predicts a significantly different “divergence distance behind aperture” value. I think that is not physically accurate.

The calculator is essentially using two data points to draw a line to calculate this distance, the beam size at the aperture (which it assumes is the same size as the aperture) and the beam size that you actually measure at some distance away. The way I calculated the distance is by actually measuring the beam size at 3 different distances and drawing the line. I get a different result than the calculator; the effective beam size at the aperture is not actually the width of the aperture. More measurements are needed to fully understand this.

Nice clean solder work. :+1:

Thanks RBD,
2AM project… hope it works. :smiley:
With that said I did something stupid. Hooked to Bench PSU with reversed polarity. It’s from a Thorfire BD 04 and the driver is build different (wrong, backward).
Original emitter is dead so, will see shortly if driver survived.

Very pretty solder work, and not an easy thing to do. At least, its not easy for me to do :slight_smile:

If you want to save a bit of time and effort, next time skip the center pins. Its continuous with the ground tab in the back so as long as one of those is connected it’ll all work fine.

And in most cases the base level center pads aren’t connected to the ground ring anyway so the only possible benefit is a smidge more heat sinking from the added solder mass.

The emitter size is what affects the divergence.
If it was a point source, the rays would be collimated and the spot size would be equal to the projected size at any distance, which results in an infinite candlepower.
If you use the calculator and put the same aperture and spot size you get a divide by 0 error.

Since an LED is not a point source, the spot at 10m is larger than the aperture, which means there is divergence, and that is what needs to be taken into account.
And “aperture” refers to the initial diameter of the beam when leaving the flashlight. So the beam size is literally another way of saying aperture.
Obviously if you have a huge lens and only use 2cm diameter of it you would put 2cm as the aperture, not 200cm or whatever.

+1 on on what RBD said. Looks orsm. Well done.

Thanks,
Have it fully assembled now, IT WORKS!!
Happy because it survived a 2AM Brain Fart.

That’s what D1 is for.

Coming along quite well. This is a really nice Reylight host. MTN-17DDm with 3000k 80CRI XPL HI. Still need to polish it and glue in the trits.

Yes, everything you say is fine. I’m just saying that some of the details of that calculator differ from the measurements I just took.

It really depends on how well your flashlight can collimate, this method is almost irrelevant for regular reflector LED flashlights.
I made a separate post to explain everything: The proper way of calculating lux / cd / candlepower

Getting back into it… Its been 4-5 years since I modded anything.

I thought my fave EDC of the last 5 years needed a little upgrade. Most nerve-racking part was getting the head apart with a strap wrench and small vise.

Old pale green tint XPG2… I cant remember the Flux BIN either R4 or R5.

No copper here, just aluminum.

New XP-G3 S5, 3C tint (~5k)… All gutts

Strange die, no bond wires, or die squares.

And the glory

aluminium foil wrap around triple led optic to prevent lumen wastage

It’s not really a mod :stuck_out_tongue:

I dont have a light meter but i can tell the different :smiley:

Today I “fixed” my new Astrolux S41S. I held off on this guy because there were some issues, but as soon as the improved heads started shipping I placed my order. The light came a few days ago. Overall its a really nice little light, but it had some shortcomings. I ordered mine with the Nichia 219b option, which is nice of course, but 219b’s driven hard by this little 18350 cell resulted in some serious output drop. They just sagged like crazy. Also, I learned that these little lights come with the original A6 driver, not the new tiny25 Bistro driver. Booo.

So out came the 219b’s and in go 4 219c SW40 90cri emitters. Should have a lot less sag. At the same time I fitted a MtnElectronics tiny25 driver with Bistro and the thru-board bypass, a fantastic driver. Much better. Just for good measure, and because I love them so, I added a lighted tailcap that sorta looks like this. Sorry for the crappy cell phone shot:

One final note: I was surprised to see that the light came stock with a lighted tailcap switch…without the LEDs or resistor. Just bare pads. Its the 2-emitter board like is used in the X5/X6 lights. And of course it comes with the translucent boot too. I chose to use a 6-emitter ring board but anyone who just wants a simple lighted tailcap has already got most of the hard part done in their lights.

nice one emarkd

what resistors did you use?

Thanks, it really looks better in person. I should try to photograph it with a real camera. It took some fiddling with values, but I wound up at 120K for the blue, 68K for the orange and 44K (I think, maybe 46?) for the green. They’re really close to even but the blue may still be slightly brighter.

did you use bleeder for the driver emarkd?

One more for that slick soldering :open_mouth: