BLF GT (preliminary) modding thread

[LEDtec]

Thanks TA, I’ll wait for your drivers.

[Nicolaas]

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

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

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

[Lexel]

@AlexGT

@Texas_Ace

@AlexGT

@LEDtec

I would like to mod my GT with an XHP70.2, someone can kindly tell me which resistor to replace on the original driver, and possibly which value to use?
Thanks.

I purchased a R047 from here:

10Pcs 2512 SMD Alloy Resistor R010 -R091 0.01R ~0.091R 0.05R 0.33R R020 1W 1% | eBay

That resistor while technically ok is only rated for 1W. The resistor needs to be rated for 3W for long term reliability.

I have yet to find a reasonably priced 3w .047ohm resistor myself, so I just recommend the .050 and .040 now.

Thanks for the clarification TA, I just noticed it! The cheapest I found was $20 for 100 pieces… Will this one work?

https://www.ebay.com/itm/100PCS-X-Bourns-3W-2512-0-047R-47MR-0-047-OHM-1-RES-Metal-Film-Chip-Resistor/332133259856?epid=574292028&hash=item4d54af5a50:g:YTsAAOSw32lYq0X3

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

[Lexel]

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

[g_sintornillos]

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
.

[AdrianWA]

@The Miller

@pommie

With an xp-g* why not just use one cell per holder and use a bit of wire as a jumper, that way you can easily revert back to standard, same with two cells for 6v leds, and use three cells for those hard driven 6v leds :smiling_imp: Cheers David

Ah dummy pass through carrier fillers, smart!

Or buy the solarforce dummy batteries.

[Hardusvd70]

@Lfatman

I have opened my flashlight by 2 people (my son and I) using non-skid rubber gloves.

With the stock Led obtained 925.000Cd. I have replaced it with a boiling thinner dedomed XHP35 HD and now I achieve 1.186.000Cd.

The Led I used was removed from a Haikelite MT02.

The measurements are at 10 meters. At 15 meters I get 1.118.000Cd

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

[Texas_Ace]

@Hardusvd70

@Lfatman

I have opened my flashlight by 2 people (my son and I) using non-skid rubber gloves.

With the stock Led obtained 925.000Cd. I have replaced it with a boiling thinner dedomed XHP35 HD and now I achieve 1.186.000Cd.

The Led I used was removed from a Haikelite MT02.

The measurements are at 10 meters. At 15 meters I get 1.118.000Cd

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.

[AlexGT]

@Lexel

@AlexGT

@Texas_Ace

@AlexGT

@LEDtec

I would like to mod my GT with an XHP70.2, someone can kindly tell me which resistor to replace on the original driver, and possibly which value to use?
Thanks.

I purchased a R047 from here:

10Pcs 2512 SMD Alloy Resistor R010 -R091 0.01R ~0.091R 0.05R 0.33R R020 1W 1% | eBay

That resistor while technically ok is only rated for 1W. The resistor needs to be rated for 3W for long term reliability.

I have yet to find a reasonably priced 3w .047ohm resistor myself, so I just recommend the .050 and .040 now.

Thanks for the clarification TA, I just noticed it! The cheapest I found was $20 for 100 pieces… Will this one work?

https://www.ebay.com/itm/100PCS-X-Bourns-3W-2512-0-047R-47MR-0-047-OHM-1-RES-Metal-Film-Chip-Resistor/332133259856?epid=574292028&hash=item4d54af5a50:g:YTsAAOSw32lYq0X3

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

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…

[Texas_Ace]

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.

[AlexGT]

First in line when you start selling…

[Texas_Ace]

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

Really pressing for them to make these for modders.

[giorgoskok]

@Texas_Ace

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 !

[Hardusvd70]

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

[Enderman]

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

[Hardusvd70]

@Enderman

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.

[Sledgestone]

@Enderman

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

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

[Enderman]

@Hardusvd70

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

You’re right, my bad, it’s 700-750.

[Theodore41]

@Enderman

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

Any suggestions?

[Theodore41]

@Hardusvd70

@Enderman

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.

I see 720Kcd from my TN42.