I don’t understand the desire to go with wattage in a flashlight. It’s like saying your car goes 100 mph without explaining anything about what got it there. A car with no engine can do 100mph down a very long steep grade, a car with a monster engine can do 100 mph in the first little bit back up that steep grade.
The 2 things that determine wattage, voltage and current, paint a broader picture as to what the light is doing and why while also allowing some insight into the cells used. You describe this yourself TA in that the wattage spiked at a certain voltage, so the cells used will determine a lot of things, if they can’t keep up they will sag, the Buck drive will pull a heavier load on them to maintain, and the light, while still making the required wattage, will be well on the way to being dead in the water with the cells depleting at an ever increasing rate. A better cell would allow less draw for the wattage requirement of the Buck driver and as such, would have a flatter drain curve with a more consistent output and run time.
Like having that monster engine running up the hill with high octane fuel vs. cheap unleaded gas. (Reminds me of the story my dad tells, racing his brother when his brother had the newer more powerful car. Dad knew he was going to win, because he’s canny. He set the race rules, they raced backwards up the steepest hill in town. Dad raced right up over the top, Jim spun his wheels and slid partway back down the hill. Dad LOVES telling that story!)
Of course, I’m probably fairly wrong and just talking to fill the time in the day….
Years ago I used to ride a single cylinder 600cc motorcycle in a hilly area where non-professional road racers would go.
I had my bike down to just under 300 lbs and those with four cylinder bikes learned the advantage of high torque and low weight. Of course when we got to a straight away I was left behind.
You remind me when I drove a VW beetle in the early 70s,and when I was riding on a hilly road,I was first,but when I got to a straight way I was left far behind.
My Convoy L6 finally arrived yesterday. I love it already! :+1:
Overall fit and finish is excellent, the beam is nice, and the anodizing feels great. It’s heavy, but well balanced and comfortable to hold. I really like the lack of branding and logos.
My only gripe is that the rear switch feels “mushy.” At first I thought the boot’s nub was too short, but the switch itself moves almost 2mm before it makes contact.
Can anyone recommend a suitable replacement forward-clicky switch?
The PCB is 22mm diameter. Base is 12.95mm x 17.97mm, switch is 13.28mm tall when off. The switch has no visible markings, but I haven’t desoldered it to check the bottom.
In a linear driver you are correct, amperage is a good indication of performance.
In a buck driver though it tells you basically nothing, except maybe the quality of the cells IF you know how to interpret the data.
In a buck driver high amp draw is actually worse, it means the voltage is sagging more and it is having to pull more amps to compensate and keep the wattage the same.
When people were comparing cells in the S70 they kept acting like higher amp draws was a better battery, in reality that was not the case. In fact higher amp draw was actually the worse cells.
We never have the voltage to go with the amp reading, the amp reading alone tells you half as much as wattage which at least uses 2 data point to acquire.
Edit: But yeah, that story is why I am against Buck drivers and regulated circuitry, it’s really tough on the cells. For those lights though I like to take a forward voltage reading across the emitter and an emitter amperage by making a loop in the negative lead wire at the mcpcb with my clamp meter telling me what the emitter is actually seeing. Comparing those numbers to what the tail current is can also give an accurate rendition as to the efficiency of the driver in bucking the current down to the emitter. Of course, if forward voltage and emitter currents approach actual draw on the cells through the Buck driver then… of course it’s not quite that way with the L6 as the emitter is 6V with an 8.4V power supply and a forward voltage approaching the same voltage as the power supply if the driver is bumped for more output. So it’s more efficient in stock trim, makes a lot of heat and shortens component life when bumped…
Might be easier to just make it fit better instead of replacing it. I use hot glue to build up the little post on the button a bit. If the glue is hot enough, it should cause the top of the switch button to just barely start to melt and make it permanent. A bit like welding plastic I suppose.
I understand what’s being described here and while it doesn’t bother me I don’t disagree that it feels a bit mushy. The S70 switch has the same mushiness. I’m not going to call it a high priority fix but I can see if Simon can have a boot made with a longer post/nub to cut down the air gap. I like that idea. I also like the hot glue suggestion as a true BLF style fix PD. :+1:
As I said, I love the L6. I know I’m nitpicking about the switch.
The mushiness is really only bothersome when using the switch as a momentary.
Thanks for the link. That switch is a couple mm shorter than the original, so it may require a boot with a longer nub or some building up as PD suggests.
There is hardly any air gap between the boot and the switch button on my L6. The play is inside the switch itself. With the switch removed from the tailcap, I can push the button about 2mm before it makes momentary contact.
Do you mean to build up the switch button enough that it is partially depressed by the boot while at rest, or to eliminate an air gap like J-Dub mentioned?
You can also place a thinner spacer (washer) between the switch and boot, which will place it closer to the boot nub when retainer is tightened. I have found some really thin washers .500mm (shims) that you can stack and thicker ones, 1.5-2mm (fender washers) thick out of steel and brass. Or just sand down the original one a little at a time, to get that custom feel!
Of course taking an amp reading from the emitter is ideal but that is about 1% of the amp readings you see posted on here. In fact I don’t think I have seen one posted for the L6 at all. I don’t even like taking them as they are quite a pain to do in a fully built light.
Buck drivers are actually quite good, they are not really any harder on the cells then a linear driver (in fact they are easier on the cells then a true non-pwm linear driver due to far higher efficiency) and they will produce more lumens for a given current to the LED as well, so it balances out. A well designed buck driver is by far the superior driver when compared to a linear driver. This is why you basically never see a linear driver in a high end flashlight, they always use buck / boost drivers.
Boost drivers do pull a lot more amperage from the cells in order to reach the higher voltage. They still work fine but are much harder to design and deal with due to the very high currents they need.
It doesn’t really matter in the long run but if people are going to compare numbers they need to have numbers that can be compared. In the case of a constant current buck driver there is not a lot of need to compare numbers unless you are using really bad cells.
