David - I just got in 3 of the 22 mm PCB's in from OSHPark. I could order the parts kit from RMM, but I'm not clear on the LVP option - there is no order option, but in the description, it lists an option for no LVP, 2 cell, or 3 cell. So, I'm confused... Not sure if he means the option is implemented in the firmware, or required something different in the parts list... Just not sure, dunno...
How many do you need? In theory, I can get/or have the boards, order the parts kits from Richard and program them myself with firmware of my choosing for you. Just not sure bout that listed LVP option in the description.
I think LVP is in firmware. Richard has the driver listed with 4 firmware options. Only the guppydrv option doesn’t have LVP. The other firmwares have the option of ~6V for 2S and ~9V for 3S support. Right now, I’d like to get a couple to try out. (I learned long ago to always get one extra to break/lose/burn/whatever.)
Hey guys, I hope nobody is really invested in the 20mm boards. They work great at lower currents, but if you try and get 4A+ out of it they bug out. I screwed up on the layout and need to redesign some things. So far the 17mm and 22mm are solid and I have been using them pushed hard in a few of my personal lights, as have several others, but the 20mm needs to be tweaked.
In short: if you have plans to built a high-power 20mm driver, hold off.
On a positive note, if you want a solid 5A 17mm driver, the 4-layer PCB has been running great for me. I've been running it for a few weeks now and have built a few and they are all working great.
5A 17mm board ? Yes please ! how do i order one of these ? I was going to make an adapter for the 22mm board for my 1405 but this will save me the trouble.
Thanks
17mm? I have built about 50 of them so far and they've all worked. 20mm--well, you read my post earlier (no go for most setups). 22mm I've built and have been using about 6 of them in lights and they've all worked so far.
A lot of the issues you'll run into is that reflowing these boards properly is much more difficult than anything else we usually do because of the tiny pin pitch and non-existant leads. A stencil may help a little bit (although I don't use one for these), but really it comes down to some practice and then following up with a manual reflow of the leads with your iron on the sides of the flat packages after the initial reflow, if needed.
Soon! I have been testing them and I have a few test samples going out to other members and flashlight guys as well to make sure they're 100% before the "official" release.
The first two I have no clue. The second one I made wouldn’t work so I put it away to take a break. I got back to playing with it a couple of days ago and absent minded me fried it. I forgot to change my test bench setup back to 2S. I inserted the batteries like it was 2S in my side by side battery holder. Well, it was 1S and the way I have it set up also means it was reversed polarity to the driver. It smoked. I dunno what fried but something did. It also blew the LED too. I’m just gonna take all the components off my first one and reflow them to see if I can get it to work.
So for future reference to others, 1S reversed polarity doesn’t get along with this driver
I haven't tried to reverse one, but I think that cerealkiller said that he had reversed polarity to this same IC before and nothing happened. He said he had even measured the LDO output and it also didn't reverse.
As far as the non-working drivers go: I can almost guarantee you that it's your reflow of the MCU, Buck IC, or both. The MCU is usually the culprit.
Hi Richard. Have you done any specific efficiency testing of this driver with an MG-G2 in high, medium and low modes? Alternatively, have you sent any to HJK for testing? Thanks
The way I understand it, those are two different data points. The driver is outputting 2amps at the emitter. When the input is 8.4v, the input current is 1.6amps. When the input is 6v, the inp[ut current is 1.2amps. You can’t really do the calculation correctly without knowing the forward voltage during his testing, but I guesstimate by just saying Vf is 6v.
So the equation would be (6v*2A)/(8.4v*1.6A) = 89%
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I think.
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I would be more confident, but I feel when input and output voltage are the same (6v) the input current should be much higher than 1.2amps, so I’m probably reading it wrong.