Convoy L2/L6 modding thread

If your using a multimeter your never gonna get accurate results. Clamp meters are the way to go. Most folks on this forum use the Uni-T UT210E. There were some coupon codes for it at Banggood for $28, but I think they expired. I ended up buying mine on Amazon for $38. It’s a great ammeter, but so so voltmeter. It’s got the features I need like auto turn off so I don’t run down the battery. I hate that!

Here’s a 300 piece kit for $1.53 on eBay. http://www.ebay.com/itm/172555310586

Here’s mine.


This time I covered the resistor in heatshrink for safety reasons. On the 3rd one I build I’ll put the resistor floating in the middle of the wire for durability reasons. I broke the connection between the resistor and the switch getting the first driver out to put the TA driver in. Gotta revise the design. :slight_smile:

Couldn’t we just take power off the #8 leg of the MCU for >5.5V as controlled by the Zener or LDO? Then it wouldn’t take as high a resistor value because the voltage would be closer to the SMD LED requirement. Am I thinking right? I know the MCU has a 5.5V max, so…

Thanks Jason, I think I’ll just use an old pcb and carve a block out of it with 2 pads on it for my resistor to solder to, then I can put it inline on the positive lead and the metal caps on the resistor won’t be holding the wire, the board will. That should work. :slight_smile:

No, this would effect the voltage that the MCU sees since it is simply a 200ohm resistor that is dropping the voltage for the mcu (the zener is there just in case for voltage spikes).

Using a high value resistor is not an issue in the slightest anyways, this is how most LED’s are ran.

You could even use a pot to make it adjustable if you had enough room, in fact on larger drivers like the Q8 that would be a very good idea.

What’s wrong with using a high resistor value? Should be no big deal. 2 LEDs in parallel with a 15K resistor is giving me a 0.4 milliamp draw. The driver itself has a 0.08 milliamp draw. So 0.48 milliamps in total.

On the TA driver I have, does that “power on” positive pad give full battery voltage? I didn’t check. I assumed it did.

When I was doing these lighted tail caps on a Bistro driver with a single cell, each SMD LED took an 11K resistor for the low glow I like. So the pair in parallel would take a 22K, right? But that was single cell, so would I use twice that for the 8.4V supply of the L6 to get a similar result… like 44K? Or to get even a bit lower a 51K?

I cut a rectangular portion off an old driver that has two pads on it, soldered a 51K resistor to these pads. Then I soldered a 22ga lead to each pad, inline, and will either use shrink tubing or a cocoon of JB Weld to insulate it. Does this sound right or way off base? I want a low glow, not even discernible in a lit room but visible in the dark.

Haven’t hooked it up yet, wanted to check here and see if I was thinking right.

Edit: Just realized that on the Bistro with lighted tail cap there was a bleeder resistor off the driver, so the full cell’s Voltage wasn’t going to the two tiny LED’s to begin with and I still used an 11K resistor. Hmmmm…. so what value should I use?

The value totally depends on how bright you want it. 25k-50k is a reasonable guess for 2S input.

I generally find that ~50k of resistance is ok for tailcap LED’s @1s but I have them pretty dim, With 2s input they will be twice as bright, which should be ok.

So yeah, I think a 51k resistor should be a good starting point if nothing else.

You can simply hook it up to 2s batteries to see what it would look like.

What color are you using? The white are definitely brighter than the orange. 50k sounds good for a darker color. White might need 60k or more to give what your describing.

The reason I originally soldered the resistor to the switch was so I could pull the switch out and do a quick resistor swap and not have to pull the driver.

Dang, I should have thought of that. Lol

Thanks Guys! :smiley:

SOOC Canon 1DsMkII w/50mm f/1.4 lens, f/1.4 at 1/15 second ISO400 Medium JPEG.

Edit: The background ambient light looks the color it does because I have 5% Limo Tint on our storm windows from when my wife had Migraines so bad. :wink:
Edit II: Just an FYI, the quilt on our bed was made by a group of lil ol ladies at her church when we got married, 14 years ago. Hand made stuff, just can’t beat it! :smiley:

This seems to be messing with my ramping firmware, holding the switch down to ramp then releasing it the light turns off. Makes it unreliable to shift directions for the ramp or even use the light. :frowning:

Normally, powering up the light at the tail switch gives a blink through the emitter to show power-on, now it might blink or it might come on the last mode memory. So, reliability has been compromised with these led’s on the same circuit as the switch.

Well that’s no good. Where are you getting power for the LEDs from?

One way to fix it for sure is to cut the traces from the 2 leds negative side so they don’t share the blue negative wire. Run a seperate ground wire for the leds. That way they are completely isolated from the switch.

I’ll have to look at the switch some more later because I have to sleep now.

That’s what I was thinking, separate the ground to the switch from the ground to the LED’s so there’s no disruption in the switch circuitry that toggles the ramp… Gotta figure it out cause now I really like that hot pink glow… :smiley:

Here’s a potential fix. Use the 2 pads on the back of the switch as led positive and led negative. You’ll need to use an exacto knife to cut the pcb traces around both negative LED pads.

Then run a small wire from one negative led pad to the other negative pad. Flip the polarity of that second LED so the 2 LEDs are in series. Then what used to be the positive led pad becomes the negative led pad. This let’s you use the pad on the back of the switch for a ground wire.

The only hard part is cutting the pcb. Running a tiny wire might also be tricky due to the small space.

thats not true
in a 1s Setting lets say the SMD LED draws 1mA and has a voltage of 3.2V at that current
on 4V Battery voltage the resistor needs to drop 0.8V @1mA
R=U/I=0.8V/0.001A=800 Ohms

on 2S Setup
on 8V Battery voltage the resistor needs to drop 4.8V @1mA
R=U/I=4.8V/0.001A=4800 Ohms

So if you use 1600 Ohms on a 2S setup doubling the resistor value you get about 3 times the brightness
I=U/R=4.8V/1600 Ohms=3mA

I had to cut a new piece of PCB with 2 pads for the resistor, (the first one collapsed holding it with hemostats to remove the resistor) I put a 75K resistor on in place of the 51K and now the light works just fine. The SMD LED’s are still bright enough, almost more than I like as they’ll glow pretty bright in the dark. Regardless, at 75K the ramping works fine.

Same camera, same settings, same position in the same room…

Cool. That’s a lot easier than modding the switch for a seperate ground wire.

Did you say that was pink? I didn’t know that was an LED color. I’ll have look again to see if I have some.