It’s not constant current buck driver
Oh no!! Not constant current buck driver! I wish I knew before I ordered. I wouldn’t have bough it.
Is anyone able to explain this?
Not the concept of a buck FET, but how specifically sofirn is either doing this, or not doing this, either with the hs41 or with any other sofirn light that has a buck FET claim, with supporting evidence like photos of these drivers, and not speculation based on runtime graphs and thermals. Not that there’s anything wrong with runtime graphs and speculating, not throwing shade on anyone or on sofirn for that matter, I just want to actually figure this out definitively.
It’s not just the hs41 they’ve made this claim in a few different places and everytime there’s runtime graphs or thermals that seem to suggest otherwise and that’s it, case closed, but I think there might actually be something to this. A buck FET would get hot wouldn’t it? And it would have poor regulation on the high modes. Maybe it’s just not a great buck and only doing anything on the lowest modes that rarely get runtime graphs.
Or maybe it is just a buck battery charge controller, idk. But I’ve never seen a real explanation with a teardown where part #s are visible or components identified that can prove one or the other. Maybe because it’s hard to take these apart without destroying them. If there isn’t a teardown anywhere im willing to buy one and offer it up as sacrifice just to figure this out.
Or if someone has done this already I’d really appreciate a link.
There is no such thing as FET buck.
It’s either buck, which is good, or FET, which is crap.
Since there is no output stabilization, it’s FET. So stay away.
Sofirn and Wurkkos have the habit of cheapen out on drivers for almost all of their lights. So unless it’s reviewed to have a good, regulated driver, always assume their driver is crap.
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Well there is. You can have a regulated channel with a FET turbo. Blf members have built these drivers, so we know they exist.
There is output stabilization, theyre doing the bottom of the ramp with no PWM.
Theres a big inductor on the sofirn “buck FET” lights. I don’t think it’s the inductor for charging, the datasheet for the charge controller says 2.2uH-10uH for its inductor, there’s a 2.2uH inductor next to it, its a second, bigger 0.47uH inductor that the FET+1 drivers don’t have. No 7135 chip on these either. So how do they do moonlight with no PWM and what’s this inductor doing?
Maybe it’s just not the best buck driver? But what else would you call it? Idk what it is exactly but it’s not a direct drive FET.
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I don’t care if it is regulated in moon light mode because why?
In all other modes it’s runtime graph is a down ward slop so no, for all intents and purposes there is no regulation for this headlamp.
That’s not the point. Let’s say it turns out it is using a buck driver. Now you know you don’t actually want a buck driver in this light.
I don’t know that it is or not, I’d just like to find out. I think theres something lost in translation here. It’s not just the hs41 they’ve said this about. Let’s find out what the deal is.
There is no ambiguity. It does not have a buck driver, because a buck driver does not behave like that. The old saying if it moves like a duck and it quacks like a duck, it is a duck. In this case, it is a FET driven light, like 95% of their offerings.
Don’t think it’s possible for a direct drive FET to have no PWM anywhere in the ramp