Because there has to be one. Right? Here’s what Hank said about it, if you haven’t seen this yet (was posted awhile ago, not my conversation)
for the 9A and 12A driver, it is only the resistors which are different, there are no other difference. There is no downside to use the 12A driver, it depends on the customer’s preference.
But there has to be some downside right? That’s just how life works. Pros and cons to everything. And I get it, he said that because there’s probably no downside that anybody would ever notice, and who doesn’t want higher regulated currents. But just humor me here.
A downside must exist. I don’t understand enough about these drivers to understand what exactly that would be, but id make a guess that the boards with 12 amp linear FETs would get hotter than a 9amp when theyre both run at their respective max regulated limits, but is that better or worse than just going to turbo? Lower in the ramp is there a difference in efficiency? Might one be harder on some electronics than the other in some scenario?
What about between a 5a linear and a 12? People seem to want higher and higher regulation. Why not put 12a on everything? I mean, everything that could handle it. Quads with good current handling LEDs etc. Cost? More stress on internal components? Something right?
I know that on some of the 5A linear drivers, there wouldn’t be exposed components on the battery side, though that was only the KR1 and KR4 drivers from what I’ve seen, don’t have a D4 with a single-sided linear driver. It lets you use slightly longer batteries, as otherwise it might damage the exposed components or hit the brass spring-stop.
They all use the same firmware, but the ramp table was calculated with a 5A regulated channel in mind, with a 12A regulated channel the ramp will have a different shape (brightness increases faster).
Also more heat gets dumped onto the driver instead of the LEDs at a power level above 5A, it might make the thermal step down more abrupt, but maybe it doens’t have a very noticeable effect in practice.
Going from 9A to 12A linear generally means everything will use about 33% more power and be very approximately 33% brighter. The ramp makes that mostly not matter, but it tends to have brighter moon too… and as others said, it could impact thermal performance and make turbo seem like an even smaller step up.
Also, depending on the LED type, it could become an issue. If your LEDs can handle 9A but 12A is too much power, the higher-power driver would be a bad idea. Like, in a 4x219B light, I would probably want 8A max, but in a 4x519A light I would probably want more.
I wish there was a reference for all of Hank’s drivers somewhere. When I order a Hanklight I don’t really know if I am getting the best driver available for that light or not.
Shorter cell run times, harder use on cells, considerably hotter light in Turbo. And yes, much shorter Turbo until step down. All combined makes for an overall less useable light UNLESS all you want is max output in short 15 second bursts every few minutes. In that scenario 12A would be more ideal… considering like TK said, IF the emitter choice is cooperative.
If he’s stating that it’s 9A or 12A as achieved through resistors then it’s limited by the resistors. At any rate, burning 12A makes more heat, regardless how it’s achieved.
A true FET drive is still limited by cell choice. And wire ga. And emitter choice.
Always a series of compromises as every choice introduces different resistance parameters.
Like how your car gets different gas mileage depending on the variables you introduce. Tire pressure, load in the car, speed you drive, grades you climb, even wind speed and ambient temperature as well as humidity level. Variables are ever present and ever changing.
Cell ends get slight oxidation, as do contact points, do you clean these? DeOxit Gold can bring you to maximum output.
It’s a vicious circle, looking for absolutes. Believe me, I go to great extremes looking for what a light is capable of… for no other reason than because I want to know. And, well, because I can.
Yes there wont be any difference about the max output. The difference are only in the regulated part of the ramp.
My guess is that it doesn’t matter much, in these small lights the output drops very quickly and the top part of the higher output regulated channel would be barely used.
Maybe I should be more direct. Direct drive uses the most current from the cell, draining it faster. Heat causes thermal protection to limit power to save the light from itself.
More power is always a path to less time. Through cell drain as well as heat.
You can’t regulate a light at power levels the cell cannot maintain. Oh, you might regulate it for a minute or two, but the lower available Voltage will ultimately cause regulation dropout. Even with a good Boost driver.
I like to make it personal, think of my demands on the light in terms of what I expect from myself. I can carry 30 pounds all day. 300 lbs is another story.
In general, just select the LEDs you like, and let Hank pick the right driver and firmware for it. He matches things up pretty well. The main driver choice for you to make, usually, is whether to pay extra for a boost driver.
His boost drivers have a lower maximum brightness and a higher moon level… but they are significantly more efficient so they run longer with less heat, and less heat means they can sustain higher output levels.
I’m generalizing here, but as a rough ballpark idea what to expect…
Info I found on Redit suggested the driver you get also changes if there’s a backlit switch. Apparently the 12A driver doesn’t support the backlit switches so a 9A is fitted which does support them. However, it is possible to fit an RGB switch with the 12A driver and run it off the aux lights (but Hank doesn’t normally do that.)
That info might be outdated. On Hanks Website on the DT8K product page, it states “• 12A constant current + FET (non FET for the E21A version)” yet both of mine have the lighted switch.
That’s info from Redit and a conversation with Hank over the last week or two. I bought a D4SV2 in January and requested the back lit switch but it arrived with the non lit switch (specs: standard driver with W2 LED’s.) When I asked Hank about retrofitting the lit switch he said it was incompatible due to the hardware. I check via some pictures I found on the drivers he uses and I’ve got the 12A driver.
It turns out (after lots of questioning) I can retrofit the RGB switch by paralleling it off the RGB aux lights, but it appears he doesn’t use that driver with the back lit switches.
After putting a RGB button and D4v2 driver into a light, I have so much respect for the people who specialize in modding Hanklights and other RGB-aux lights.
