My Convoy L6, lighted switch, TA FET driver plus mods

Flashlight Modding and DIY Parts
8

This section is about the SMO reflector and throw numbers.

I decided to see how much throw I could get. I bought a SMO reflector to experiment with. I shined it on the ceiling with the stock centering ring and then I removed the ring and added some insulating tape to the bottom of the reflector. This allowed the reflector to sit lower which changed the focus. You can see in this picture how lowering the reflector just a tiny bit reduces the size of the corona and puts that light into the hotspot which increases the lux.

I knew this required more investigating so I cut the bottom off the reflector and bought some new, longer panhead screws to bolt the emitter down.

I also experimented by slicing off the xhp70 dome. You can see that this shrinks the hot spot and increases the intensity.

I bought an inexpensive LX1330B lux meter and did measurements at 5 meters, at about 30 seconds in and with fully charged KeepPower protected 5200 batteries. I then calculated it back to 1 meter.

With the stock driver and OP reflector I got 58,000 lux or 481 meters.

Then I added an R082 resistor and got 65,000 lux or 510 meters.

Swapping in a stock SMO reflector gave 81,250 lux or 570 meters

I then tried a new xhp70 of the same N4 1C bin, but I got slightly better results.

OP - 71,500 or 534 meters. A 10% increase.
SMO - 86,250 or 587 meters. A 6% increase.

Next I cut the bottom out of the SMO reflector so I could adjust the focus better.
I got 92,500 lux or 608 meters.

Next I sliced the dome off.
I got 115,000 lux or 678 meters

I pretty much stopped there. Even though my measurements are lower than others, I did pretty much double my lux from 58,000 to 115,000.

Matt at Adventure Sport Flashlights did most of the same mods, but his measurements were all higher. He ended up doubling his lux as well, so I think we are about even.

Here’s his video on it.

One potential reason Matt got higher numbers may have been due to batteries. After all these lux measurements I bought some Liitokala 5000’s to compare to my original Keeppower protected 5200’s. My battery tests show the Liitokala cells always drew more amps than the KeepPower (7 amps compared to 5.7 amps). This extra amp draw results in higher lumen output. Maybe Matt was running better batteries than me? We did use the same model lux meters, as well.

9

My thrower version of the L6 with R100 added to FX30 driver and SMO reflector. This is before the FET driver. The stock light could never reach those warehouses. With the FET installed, it’s even better than these pics! Lol

Here’s a few shots of the xhp50.2

I tried it at 2 slightly different reflector heights. They are pretty similar. The 50.2 with dome on seems to match the size of the xhp70 with sliced dome. I’m guessing the 50.2 with a sliced dome would shrink the hotspot size again.

With the camera settings turned down you can see the dark center.

I probably should have taken a few lux meter measurements while I had the 50.2 installed, but I didn’t. I ended up buying a new xhp70 to put back in and I adjusted the reflector depth to give a bigger corona creating a smoother hotspot while reducing throw. I don’t need max throw, just a good compromise between throw and a nice looking hotspot.

10

Nice comprehensive write up Jason. :+1:

11

Thanks.
It’s way too much for me to remember so it’s mostly quotes from many other posts I’ve done. So the verbage might sound funny at times, but I’ll eventually go through and tweak it.

12

Good stuff, nice it has it’s own thread :+1:

13

Wow! Nice job on this! Just updated my Convoy L6 with the latest NarsilM v1.0 and all is working well. Ramping is doing good Pulls 18A, 186 kcd, intense hot spot, no black hole with SMO reflector, running the XHP70.2 P2 3B, 8,090 lumens @30 secs. This is with dome, but hoping to try sliced dome next.

Last night with 2 LK 5000's at 4.00V, it still gets 15A on a clamp meter. Last night I added solder blobs on the LK's. Before I was using a JAXMAN spring adapter between the cells, but the spring was bypassed with a short 24 AWG wire.

Just tried setting moon level to PWM value of 1 via the UI and it's wild - the XHP70.2 literally barely glows - noticeable but not measurable - amazing. You can tell it's on because the yellow of the phosphor turns slightly whiter than the phosphor on the LED base.

14

Looks like you are having fun with this light :partying_face:

Cool write-up for others who are modding this light. :beer:

15

Last night I charged up the solder blob topped LK 5000's to 4.20V and re-tested. Actually I use only one that's solder blob'ed since there's a driver spring, bypassed of course.

Amps at the tail: 17.3A, lumens: 9,210 @start, 8,160 @30 secs, and 193 kcd @5m (879 meters)

Parasitic drain is 62 uA (no indicator LED on this L6), so pretty happy with that low reading. No need to turn off the power switch.

Thanks to steel_1024 for the XHP70.2 P2 3B!

It's an impressive thrower, but way too much heat to handle, but that's what thermal or timed step downs are for.

16

I use Narsil v1.2 so I can have the lvp, but you can’t have that and thermal monitoring at the same time.

Maybe v1.2 has a timed stepdown?

That’s no big deal as I use my hand to monitor temperature. For normal use I adjust to slightly below turbo output. You still get bright output, but much less heat and battery load. That’s much more practical. Then as the voltage runs down I go back to full output.

I save the full output with fresh cells for testing or showing off. Lol

17

NarsilM has LVP and thermal step down for 2S setups. v1.2 had a poorer ramping table as well. Bunch of improvements in NarsilM.

Not sure I can afford the time to look back any more at old revisions, unfortunately.

18

The stock driver is a buck driver, tailcap amps are basically a useless measurement for buck and boost drivers.

Buck drivers keep a constant output current but the input current will vary with voltage. Higher input voltage = lower input amps and vice versa. So in this case the lower the amps, the better the battery.

19

Cool write-up Jason! When I want to mod my L6 I will find my inspiration here. The lighted switch will certainly be on the list! (and XHP70.2 and SMO reflector).

20

he got v1.2 with my improoved ramping table

21

What? I’m pretty sure the FX30 is a constant current driver.

22

It is a constant current buck driver. That means the output is a constant current.

The input current is anything but constant though. It will pull as little or as many amps from the battery as it needs to keep the output constant.

So if the cells sag to 8.0V it will pull 4.6A from the cells (aka, at the tailcap)

If the cells sag to 7.2V on the other hand then it will need to pull 5.1A in order to maintain the same output current.

Amps x Voltage = wattage. Wattage is a much better way of thinking about buck and boost drivers as the LED Vf doesn’t change much.

8v x 4.6a = 36.8W
7.2v x 5.1a = 36.72W

23

It’s funny because I’ve done a ton of amp draws on the FX30 and never noticed the amp draw at the tail increase as the batteries went down. In fact, as the batteries went down I could notice the output (both amperage and lumens) dropping. It did stay pretty bright at first, but below 3.7v or so it was noticably dimmer.

I wonder why these driver specifics were never mentioned before in any of the L6 threads?

24

I and others have mentioned them before many times. Even put the driver though a full test on the bench to see exactly what it did.

The output remained more or less constant from an input voltage of 8.4V down to around ~7.8V. The output them spiked a bit for some reason from 7.8-7.6V before dropping back to normal until it could not maintain regulation anymore. Somewhere in the low 7V range (which would be about 3.7v per cell). Although all of this is from memory, so don’t take those voltages as gospel.

At that point it was just a high resistance direct drive driver and output would drop as voltage dropped.

This is exactly what you would expect from a cheap buck driver and how it is supposed to work (minus the spike in output in the 7.7V range).

25

I’m sticking with FET drivers in the L6. :+1:

I did try the xhp50.2 with the FX30 and wire across the resistors. I didn’t have my clamp meter then, but I think the amp draw was 9 or 10 amps. I didn’t even think the FX30 could handle that much without smoking something.

26

Thank you for your pictures and information. Today I finally put Kaidomain driver and leds on switch :smiley:

27

Great work Jason! I like the lighted button. Maybe I need to buy an L6 again :smiling_imp: