To protect another diode from reverse? Whatever…
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Well, one driver had it desolder itself from one pad, that only worked on turbo afterwards. The driver in the photo ended up shorted out and cooked the spring.
Every failure has happened with the customer, it’s been shipped out in perfect working order, so is it possible that customers are reversing the cell and RPP fails?
Tried getting Simon to look into why the component fails, but he said it’s the first he’s hearing about it, so it’s been left as is.
LEDs can’t take much reverse voltage and fry very quickly if subjected to it. Inductance spikes can easily be tens of V depending on a lot of factors, and an antiparallel diode clamps those before they can kill the LED.
Nah, this can’t be for RVP. The Schottky couldn’t take anywhere near the current necessary for that (and also the forward voltage drop would be crazy). It’s also connected to the driver output, so some sort of output protection for either the rest of the driver or the LED.
Hmm, I’m not sure there are inductance spikes, as this one seems to be a FET driver without inductors: 22mm 3V 12A FET driver - Convoy flashlight
Ok I checked the driver in more detail as it just arrived via mail. This diode is definitely a freewheeling diode antiparallel to the LED to protect it from something, induction spikes are my best guess.
However, the driver has no RVP at all, and when you connect a battery in reverse, it gets shorted through the FET Bodydiode and this Schottky. So I am pretty certain these things burn due to wrongly inserted cells.
If it were not the Diode, something else would die (or it still does, dunno) since te driver has zero RVP.
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It makes a lot of sense. User errors do happen to the best of us. I did insert batteries the wrong way a handful of times and realized my mistake before screwing everything shut.
A driver that takes 22A flat top battery input and has no RVP is a disaster waiting to happen.
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Maybe a short somewhere or a battery i serted backwards. That looks like some kind of protection diode as others have said.
Thank you for this information, I need to include a warning in my manual and website. Maybe I shouldn’t sell it when it’s so easy to make this mistake.
Simon should be updating the driver with RVP.
I’ve always been very confused why they fail when the flashlight gets thoroughly tested before I ship it. This most recent case was upon arrival, it never worked.
I had to stop including the button top adaptor on the 3X21D because customers kept flipping the cells and blowing the driver. I include button top cells and haven’t had an issue since.
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TBH flat top cells are meant to be welded in a pack and not handled individually. It’s also what it says on the wrapper. It’s so easy to put them in the wrong way cuz you can’t even tell the polarity by feel unless you are really pedantic.
I was thinking of reselling some classic flashlight to earn some coffee money. However I’m afraid that it burns the customer’s house down because they mishandle the battery LOL.
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Could you please add an option for the 3x21D with everything except SBT90 LED?
Host + Driver + 9090 MCPCB
@Simon_Mao Is there an update on the 22mm driver version of M21A?
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I actually use a black pen to mark the + & - of each cell. I reckon they just don’t read the instructions unless it doesn’t work.
Could you elaborate on what you mean by this? Were you told the driver is being updated?
The sales page on AliExpress says the L21B does have RVP, which may evidently be incorrect.
The 8A buck driver does have RVP. It’s the cheap 22A FET driver (which usually comes with SBT90.2 configuration) that doesn’t have RVP and is prone to short / explosion if the battery is reversed.
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Understood, thanks!
Rated at 12A, but pulls over 22A with a P42A.
I was wondering if that “12A FET” driver was linear or not. Seems not.
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Hey Simon, is the stainless S6 still in production? Will it be the same as the S7?
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Three throwers.
L21A with SFT-90 6700K, Ampace JP40, FET driver
M21B with SFT-40 5000K, Samsung 50S, 5A Buck
S6 with SFT-25R 5000K, Vapcell M11 II, 5A Buck
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I had three new 17mm 6v 5amp bucks boost fail in a row, has anyone else had any issues with these lately?
They lasted a few minutes, tested the light, changed the mode and all three seemed to let the smoke out when turning back on. I have not ran the rest of my order of them yet…
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