Desire to DIY fix my Trustfire TR-1200

Hello everyone,

As a part of my first serious flashlight order from DX back last year, I recieved a dud of a Trustfire TR-1200.

I have viewed many threads regarding tail-cap current on this model, and mine is seeing 1.04A with two fresh 18650's, which is around half of what was advertised.

I guess my question is, where do I go from here? I've seen that the driver was changed when the "bad" ones came about, what type of driver is in here? Which driver would I order? I'd actually prefer to "mod" this one myself to gain a better understanding of the workings of these things.

Is a 5xQ5 even worth playing with, or should I just up and drop-in something else? I have the new SkyRay 3 * XM-L on the way already, and maybe this thing will be better suited as a 350 lumen book end, while I play with the big boy? lol

I also have a TR with 5xQ5, it came with a 1 mode driver, that I changed for this 5 mode one:

I just measured 2.35 Amps on high.

It is my brightest light, surpasses my XM-Ls driven at 2.8 amps.

EDIT: it surpasses my SINGLE XM-Ls

I have the newer model TR-1200 which seems to be much better driven and it is a very bright light. It is easily brighter than my previous Mag-Mod using a single XML driven at ~3A. It also has a much better tint. Since you already have a 3x XML on the way, I would probably just replace the dropin with a single XML unit such as

If I'm not mistaken, your tailcap reading with 2 batteries should show half of what it would be with one battery. If you are getting 1.04A with two batteries then it is actually delivering 2.08A (2*1.04). There is nothing wrong with your driver. I'm sure if I am wrong someone will chime in and correct me. I'm still learning lots too. ;)

I'm still learning too, but I think the leds are wired in series (I dont have the flashlight here with me now), so if each led was to receive 0.8Amps (@17.5V) x 5 = 4Amps, and that means 2A at the tailcap using 2 batteries (not considering efficiency).

This new version is ok, and it is not worth modding. Very bright is stock form, I would guess some 800 OTF lumens. and the throw is over 20000 lux at 1 m. I replaced central led with XP-G R4 neutral, and another one with XR-E R2 WH to soften otherwise very nice snow white tint. Also added 52 mm AR coated lens from KD

Tailcap amps are tailcap amps... The power provided (in Watts) is what changes.

P=VI - Assuming a V level of 3.6V per cell @ 1.04 Amps

For a single cell 3.6V x 1.04A = 3.7W

For two cells, (3.6V x 2) x 1.04A = 7.2V x 1.04A = 7.5W

Raising the voltage reduces the amount of current needed to achieve a given amount of power.

7.5W without adding any losses for driver circuitry is pretty poor for a 5x XR-E Q5; That okay for two emitters and would be underdriven for three...

(edited to add)

Okay, if the LEDs are connected in series and you are seeing a tailcap reading of ~1A, things are changed a bit... but now the driver will be stepping up the output voltage considerably; somewhere close to 18V for 5x emitters series connected. Now we need to know actual LED current so we can calculate the actual power to the emitters... Bottom line, your cells are still only providing 7.5 Watts...

Exactly, he should read more or less 2A

Using the values of the DX driver that I linked before:

- 5*Cree 15W power output
- Output current: 17.5V(800mA) with 5*P4/5*Q5 emitters

in series 17.5V (5x3.5V) x 0.8A = 14W

in parallel 3.5V x 0.8A = 2.8W x 5 leds =14W

14W / (3.6V x 2cells) = 1.94A

Cool. Thanks for the explaination. That makes it a little easier to understand.