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.

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

AlexGT wrote:

Texas_Ace wrote:

AlexGT wrote:

LEDtec wrote:

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:

https://www.ebay.com/itm/192261425351

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:YTsAAOSw32lYq0×3

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

13.6×6.3mm https://goo.gl/V3LJqr (it goes against my principles, but the link does not work without shortening it, sorry)
14×8mm http://kaidomain.com/p/S024710.Silicone-Tailcaps-14mm-x-8mm-Transparent
.

The Miller wrote:

pommie wrote:

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 Cheers David

Ah dummy pass through carrier fillers, smart!

Or buy the solarforce dummy batteries.

Lfatman wrote:

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

Hardusvd70 wrote:

Lfatman wrote:

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.

Lexel wrote:

AlexGT wrote:

Texas_Ace wrote:

AlexGT wrote:

LEDtec wrote:

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:

https://www.ebay.com/itm/192261425351

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:YTsAAOSw32lYq0×3

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…

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.

Really pressing for them to make these for modders.

Texas_Ace wrote:

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

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.

Enderman wrote:

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

Enderman wrote:

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.

Hardusvd70 wrote:

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

Enderman wrote:

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

Hardusvd70 wrote:

Enderman wrote:

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.

Theodore41 wrote:

Any suggestions?

Enderman wrote:

Theodore41 wrote:

Any suggestions?

Read above, but the LX1330B is the best budget luxmeter.

I would get the “real” LX1330B (Dr. Meter brand) , but shipping + import fees is 29$ extra !

Why do you say the others aren’t real.
Do you have a reason to believe they are different?

Dr. Meter released the LX1330B , and later the other no-name LX1330B appeared . I don’t know if the internal components and it’s calibration are the same or not .

The one that TLF tested and found good was actually no-name:
http://www.taschenlampen-forum.de/threads/luxmeter-check-1-6-ger%C3%A4te...

The first test of the XHP70.2 driver for the GT went well tonight. We just need to figure out how to bypass the carrier button top springs.

Some tweaking is needed but at least it works. More will come as I have time.

Texas_Ace wrote:

The first test of the XHP70.2 driver for the GT went well tonight. We just need to figure out how to bypass the carrier button top springs.

Some tweaking is needed but at least it works. More will come as I have time.

Maybe awg 22-24 outside the spring will fit under the brass button , haven’t tried it .

giorgoskok wrote:

Texas_Ace wrote:

The first test of the XHP70.2 driver for the GT went well tonight. We just need to figure out how to bypass the carrier button top springs.

Some tweaking is needed but at least it works. More will come as I have time.

Maybe awg 22-24 outside the spring will fit under the brass button , haven’t tried it .

For a DIY setup there are a few possible options but they are not simple. I am trying to find a more consistent option that is simpler.

Worst case this is what we might have to do.

I have the worst case situation setup in the GT right now with the ultra low Vf 80cri 4000k emitter. I am going to do some testing and see what the limits of the system are. I am worried that it could overdrive the emitter as it maxes out lower then P2 bin emitters.

Are you testing a buck driver for xhp70.2 ?

How many amps can provide max ?

giorgoskok wrote:

Are you testing a buck driver for xhp70.2 ?

How many amps can provide max ?

I am testing a Texas Avenger driver for the xhp70.2. Since the GT is so large it was pointed out that we might as well give it all the power.

The stock buck driver is good for around 6A, which is good enough but also leaves a few thousand lumens on the table with a P2 bin emitter that maxes out around 10-12A (at 12V).

I plan to order a P2 emitter for testing this weekend or next week.

In the early test I am guessing it was around ~7A but I was only using laptop cells since I did not want to melt the springs. With high drain cells it would be a lot more power.

Properly setup I am guessing it will be around ~10A+ with high drain cells and bypassed springs on a P2 emitter. That should be good for over 9k lumens (possibly peaking over 10k lumens for the first few seconds).