Can you explain why the drivers look so different?
Proto 1:
Proto 2:
If the positive voltage goes through the center spring and post, how does the negative voltage get to the driver on Proto 2 since it’s missing the bigger ring on the driver?
I remember you saying the new battery carriers are now all metal. We’re the early versions plastic on the ends? Is that why the driver needed the extra bigger ring?
The new carriers do seem completely metal on the ends. Do the Proto 2 lights now conduct the negative voltage through the driver hold down ring?
Correct, the new carriers are all metal and use the ends of the carrier itself to connect the ground, this removes the several small springs that had a lot of resistance in the prior design and makes it much less complicated.
I have been working on an XHP70 version of Giggles for awhile now. I first tried a normal XHP70 but it has a bad cross in the middle of the beam and the performance was just ok. Not worth keeping in the light it was so ugly.
I just got my first xhp70.2 thanks to Lumintop and here are the results:
I just posted the XHP70.2 P2 4000k test here: XHP70.2 P2 4000k Output test by Texas_Ace - it's over 9000!! lumens and still going strong!
It was so powerful that for the first time my my CPU heatsink could not keep up. The results above ~18A I think could have been slightly better with a better heat sink.
I also played with the focus some as well and it can be improved, although the prototype mcpcb needs a wire running on the surface and that keeps me from getting the reflector any lower. In testing with the external LED I think the beam would be improved some by lowering the reflector a bit more.
That said even with the reflector setup like it is now, it is still perfectly usable. The middle of the hotspot is just a bit darker at range.
Now for what ya’ll really want to know, what are the numbers?
As you can see from the above thread, the lumen output at 5A is just over 7,000 lumens! (more on a cold start)
I have a 40mohm sense in it right now that gives me a max of 6A in turbo and 4.8A at the top of the ramp. At 6A it is almost 8000 lumens!
The driver does get properly hot at 6A. 5A looks like it will be ok long term though. he nice thing is that the Narsil thermal regulation can act as a safety for the driver in this situation if the thermal calibration is not reset too high.
Measured throw in my less then ideal Texas conditions are about 1250m of throw at 5A and a bit over 1300m at 6A.
Although that could change with final focusing.
Overall, I REALLY like the xhp70.2 in the GT. I will try to get some beamshots when I have some free time but it basically just looks like a larger version of the stock xhp35 beamshot at close range.
At longer range it does have a bit of a dark spot in the middle of the hotspot but not enough for me to not use it. Some focusing might improve that as well, gonna have to wait until dark to see what the changes I made today did.
I will be leaving the prototype with the XHP70.2 for sure. Although I also have an 80CRI version sitting here that I think I will try out.
As far as the parts needed, it would be much easier if lumintop releases a pre-made mcpcb or if we make some ourselves.
Right now it is using a modded version of the SD75 mcpcb, others have mentioned that maxtorch might have a better mcpcb option.
This is the design I sent to lumintop awhile back:
Then you naturally need the XHP70.2 LED. RMM has some Cree XHP70.2 P2 4000K on DTP MCPCB
And the sense resistor, a R050 2512 will put you just under 5A in turbo and be a little easier on the driver. An R047 will put you right at 5A but is a little harder to find.
I’ve always had a hard time calculating parallel resistor values, but am I right to think that 2 R100 stacked would give me the same value?
I’ve got R080, R100 and R120 on hand.
How much is this thing gonna cost? It’s a pretty insane light!
The GT group buy is still open. If you sign up it will cost $155 including shipping. The retail price will be about $250.
Hi guys, I want 1. The information on group buy is too extensive. Is there a way where you pay down payment via paypal invoice and pay balance once product is ready for delivery?
I have paypal ready, but I do not log on here much so I will not be able to see all updates.
Please make it a little simpler.
Thanks.
Cool thank for the heads up!
With the now updated China paypal fees (vs US fees we calculated at first) the total came to $157 and change IIRC, otherwise that is correct.
These are much larger then the normal 1206 sense resistor. These are 2512 (so they are as wide as the 1206 are long).
That said you are correct, you can stack to R100 to get an R050.
Simply go to the thread in the above link and ask to be added to the list. You will be added to the list on the next update (CoyoteHawk is keeping an updated list at the moment).
You will be in the 3rd batch of lights that should ship early next year. You will get a PM with the payment details here on the site when it is time to pay.
Setup your email address on your BLF account to be notified when the PM arrives.
Dang, the ones I have are 1206. I thought they were bigger.
It seems like I saw a picture of the driver circuit somewhere, but can’t find it. Do you have any pics?
Del posted several somewhere in the GT thread. I have a few of the back side of the driver, not sure if I ever took some of the front.
Here is the driver. That sense resistor reminds me of clown shoes. Rediculously large! Lol
Here is the thread post with the picture in it.
.
Linky no worky.
Ok, my decision to slice the dome off was kind of made for me. I was trying different focus points and at some point something got on the LED and started the dome burning.
So I went ahead and sliced the dome off to get rid of the burn. Not my best slice by any means, my Soldering iron died today (yay, now I have to find a replacement that will not cost a ton and get here this year) so I could not remove the mcpcb from the light and it was hard to get the razor in the right position.
Still even with a less then perfect slice the results are way different then I expected. I thought the days of 50% gains from de-doming were behind us?
Turns out they are not.
With the dome on I got 450 Kcd for 1337m of throw 
With the sliced dome I got a stinking 700 Kcd for 1680m of throw!
So the GT now matches the best throwers on the market with 2x the lumens and an XHP70.2 LED!
Now for the results.
I am not sure what the lumen loss was as I can’t test the GT all put together but you can figure there is some loss, still over 6k if I had to guess.
The darkspot in the hotspot has been virtually eliminated now, only if you really look close will you notice it.
The only con to this is the tint shift, the tint shift around the corona grew significantly in both size and harshness with the slice.
Not unbearable but noticeable now compared to before when you could ignore it. White wall hunting is not it’s strong point like this.
Now it is possible some refocusing could improve this, it did with the domed emitter. Or using a cooler LED for the slice, a 5000 or even 5700k could work better but I don’t remember seeing any 5000k high bin XHP70.2’s in my searching.
I will play with the focus later and see what it does.
Wow, I am still amazed at the results, I didn’t even expect this much out of it. Goes to show what kind of performance you can expect when modders get ahold of this thing.
It worked yesterday, but it’s an unusual url. It does not end with a file extension like .jgp, .png, etc… Anyway, I posted a link to the post DEL made that he put the picture in. It seems to be working. If not, I’ll host it myself. 
Edit: Oh snap! The url changed. Maybe his host Dropbox changes the url every now and then.
Dropbox is funny like that. You can still ‘steal’ the link by quoting the post and copying the link text:
Note that the picture is a rev00 driver (and the only built sample is with me). Production units have rev04, not much functional difference and identical BOM though.
6 A is about as high as the stock components can take. Bottlenecks would be the inductor, FET and that sense resistor. At 6 A the FET and Rsense see about 1.4 W of dissipation each. Inductor is good for 6.5 A on paper, 5.5-6 A in that application.
For Rsense, the LED current is approximately:
I = (0.25/Rsense) - 0.15
Rsense is 0.091 ohm stock for ~2.5 A. Just stack a 1+W 0.1 ohm on top of it to get ~5 A. Garden-variety 1206s are typically only good for 1/4 W, so not up to the task.
Yeah, the IR gun was showing those components getting up around ~105-110c external temps at 6A, so figure higher at the junction. Still within reason but I would not use it in turbo for long periods like that.
The nice thing is that the ramp stops at 4.8A so you can use that most of the time and just use turbo, for well, turbo.