BLF GT (preliminary) modding thread

thanks, I still did not understand what is the resistor to change, over the weekend I will try again.
these seem right and at a good price
https://m.ebay.it/itm/10x-LRP2512-R040-1-Resistor-sensing-SMD-2512-40m-3W-1-55-170-C-VIKING-/192399386351?\_mwBanner=1

or am I wrong ?

Yes, that one will work fine.

Once you look at the driver it will be clear which one it is. It is the only resistor of that size on the driver. Right now it should say 91 or something on it.

I sure won’t buy @ $20, will keep looking around or just wait for your driver boards, I’m not in a hurry…

Thanks TA, I’ll wait for your drivers.

Lexel wrote: “I am working on a CFT-90 driver for GT”.

Hmmmmmm……I think I already know where part of my holiday allowance will go to :smiley:

Djozz and I did some measurements this evening, at 21, 13 and 8 meters.
Djozz’ light performs quite a lot less less then mine, so we measured only my light at all three distances.
And Djozz has his work cut out to find out what’s wrong with his light. :rage:

Results:

Djozz light: 21 mtr = 832.167Cd
My light at 21 mtr = 1.142.190Cd
Mine at 13 mtr = 1.139.060Cd
Mine at 8 mtr = 1.142.336Cd

(We measured with Djozz’ calibrated Gossen Luxmeter and deducted the ambient light @ 61Cd).

At first I was baffled by the lower readings at higher distances and thought it might have to do with the convergance of the light but I saw others posting
similar results, so……it looks like the BLF GT is already fully focussed at 8 meters.
1.142.336Cd is not bad, not bad at all, but still a little bit lower then I had hoped for.

So, thinking of replacing the led with the latest bin and maybe giving it a little more power as well, say 2,8A instead of 2,5A.
Then again, a custom Lexel driver and a CFT-90 might be really nice as well :wink: :wink: :wink:

Cheers and wishing you all very bright days and nights,
Nico

Driving a XHP70 with just a 0.047 Ohm resistor will be disappointing at 6V
This would result in 5A
Also switching frequency would not be ideal, the diode would be quite close to its limit

I changed the Inductor, MOSFET, capacitors and diode with better parts for higher currents also the switching frequency will be set to a point where the drivers efficiency gets optimal
Also reducing the current sense resistor and lowering the current control voltage divider helps reducing heat

I should get next week the 20-40A synchronous Buck driver boards that I developed for CFT-90 and going to assemble and test the first prototype

Did someone find transparent 12/14mm switch covers?
I find only green and orange in the chineese flashlight shops

The only ones I know

13.6x6.3mm https://goo.gl/V3LJqr (it goes against my principles, but the link does not work without shortening it, sorry)
14x8mm http://kaidomain.com/p/S024710.Silicone-Tailcaps-14mm-x-8mm-Transparent
.

Or buy the solarforce dummy batteries.

I got a higher reading at 15 meters when compared to a 10 meter throwing distance when I tested my GT.

Yes, most get higher readings are 15-20m.

If you do not then that is usually a sign that there is too much particulate in the air, be it humidity, dirt, dust, pollen ect.

I was thinking in driving the XHP-70.2 LED at 12v not 6v, but I have decided to wait until a better driver is available…

Speaking of said better driver. I have the parts incoming to test the prototype XHP70.2 TA driver for the GT next week if all goes well.

First in line when you start selling…

Also getting a prototype XHP70.2 mcpcb to test as well. :sunglasses:

Really pressing for them to make these for modders.

Thanks Ta , this is awesome !


Lux reading at 7 meter throwing distance for BLF GT.
1.163Mcd which give a throwing distance of 2157 meters.
.
.

Measured at 20 meters. 1.153Mcd
.
.

Thrunite TN42.
Measured at 10 meter 701Kcd

TN42 should be doing 750-800.
I would recommend investing in a real luxmeter.

NO 750Kcd to 800Kcd is much much too high for a non mod TN42.

Where did you get that from? Highest number I’ve seen is 728… The rest hover around 700.