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comfychair
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DBCstm wrote:
So, I need to change that Diode and add a 200 Ohm resistor to the PWM leg of the FET between it and the MCU, do I also need to add a resistor between the PWM pad and ground?

Yes, neither resistor alone will make it work right - at least not with the fast PWM firmwares, which has been the main drawback to these things from the start. The resistors fix that.

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The BLF comedy hour is proud to present, Dale the advanced learning curve electrician/comedian! Woohoo!

Ok, hi everybody. I’m Dale and I’m a flashaholic. A stupid one. Smile But hey, I’m also a SUCCESSFUL one! Smile I pulled the ATiny from the new BLF FET 17mm DD board and reversed it. Worked out pretty well. I pulled a 200 Ohm resistor from my Zener kit and stood it up, held it in place with tweezers and soldered it under the previously prepared PWM leg of the FET. Simple enough, the Hakko work station makes all this pretty simple, even for a rank amateur like myself.

Now for the fun and games! I soldered the power leads to the test emitter and, with my DMM between, applied power. Smoke! Aiiiiieeee! (Hooked the incoming power leads to the emitter, outgoing to the cell) Oops!

Ok, situation corrected. wired up properly now it’s gonna work right? Uh, well, seems like the little hemostats are clamped on the positive pad and negative ring at the same time. Little sparks dance around the outer thin ground ring towards the positive pad and smoke curls up! Aaaaaiiiieeeee!

Ok, now, everythings clear, we’re good to go (man I’m glad I’m using a 18500 lap pull here and not a Sony C5)

4 levels from .05 to 4.40A with nice even positive switching. Whew! Finally!

Ok, yes, I’m embarassed. But hey, it could happen to anybody! And probably will happen to a few of YOU! So I wrote this to make sure y’all are dotting your i’s crossing your t’s and minding your p’s and q’s. Silly

(And I just found out that minding your p’s and q’s is in reference to tending your own Pint or Quart of Ale, so cheers!)

comfychair
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See, I told you those little things are practically unkillable.

I think the only form of torture you left out is connecting it to household 115VAC! lol Big Smile

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When I hooked it up to my big jumper cables and the car battery, it got difficult to see anything for all the smoke, but the emitter still didn’t shine. Oh well. Silly

See how much I learned? Know how long I’ll remember any of it? lol

Wish I had some sort of excuse, but Stupidity is about all I can blame it on. But hey, I got there in the end…that counts for something doesn’t it?

So, now y’all are probably gonna tell me that I should open up my M8 and C8 and 7G5 and L2P and fix them with the resistor between the PWM/FET, right? Scares me, they’re doing so well…do I HAVE to?

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Nope, no need if they work with the firmware you have on 'em. For some reason the FET stuck on the 105C board doesn't have the issues with mode changing/acting goofy, that seems to be only on the new boards. Which is really confusing. It's not because of traces too small, I jumpered over all of them point-to-point last night and it made no difference whatsoever.

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Could it be something about the different MCU - the SSH we're using here instead of the SSU that comes stock on the 105C? Maybe even something undocumented, or not listed in the main specs but hidden away somewhere in the datasheets?

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I was playing with the test emitter, still using the lap pull 18500, and it was working perfectly. I held different levels with no problem, switched easily and repeatedly and did everything but run it on high for any great length of time. While my test emitter is mounted on copper in a fairly heavy aluminum pill, just didn’t see the need to run it prolonged at high level.

I did want to see if moon mode works. (Read, Oh Ohh!) So I soldered the #2 position to the mcu and tried it. Nada. Not even smoke or sparks. Simply nothing at all. I removed that jumper and still nada, nothing, zip, zilch. That was the ONLY thing messed with, and removed it still is non functioning.

My head hurts.

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You' re a hero, Dale, going through all this and solder your way to victory, and so is your little driver board Cool Laughing

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Actually, I left Victory behind…I used to live on Victory St. No lie!

I went back to the test rig and looked closer at the board, the tiniest of slivers of solder was still between the 2 pad and the mcu, so I picked that off with tweezers and it now works again! The number 2 position, engaged, kills it dead. Open, it works fine in 4 modes. What’s up with that?

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Looking back at the pics that Comfy posted, with a mouse-over showing where the traces are…that “star 2” position grounds the PWM leg. Why?

Where do I find information on what the “Star 2, 3, 4” are for?

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The Star 2 is supposed to go to leg 5 of the MCU, not 6. Leg 6 controls PWM.


Borrowed this from Comfy earlier in the thread.

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DBCstm wrote:
Actually, I left Victory behind…I used to live on Victory St. No lie!

I went back to the test rig and looked closer at the board, the tiniest of slivers of solder was still between the 2 pad and the mcu, so I picked that off with tweezers and it now works again! The number 2 position, engaged, kills it dead. Open, it works fine in 4 modes. What’s up with that?


Might be so low that it “looks” dead but really isn’t

I have a cheapy XM-L that I flashed STAR V1.1 on a true 105C…in moon mode, it lights the LED, but just enough to make some light…you can look at the emitter and NOT hurt your eyes..any other setting and it glare blind yourself

Since the PWM of moon mode is like 3-5 of 255 the FET might not be able to open fast enough…thus no current flow

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Correct, there's a mistake in the solder mask. Just scrape off another little spot above pin 5, there's a big ground plane above both pins.

Also, the old 105C 'napkin diagram' pic has the stars numbered from right to left, instead of left to right. I always count the dummy that goes nowhere as #1.

http://75.65.123.78/NANJG105C.jpg

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Hmmm, 28 posts since I last got on here.

Can someone summarize what I need/should/could change if possible? And on what boards?

- Matt


EDIT: I see now. Add provisions for two resistors on the FET gates on ALL FET based boards. If they fit....if they don't fit then what (thinking the Tiny15 just won't be possible)? I'll also fix of the P1/2 pads on the SRK FET driver. If anyone has been financially put out by some of these minor oversights please PM me and I'll replace your boards with new ones for free.

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Mattaus wrote:

Hmmm, 28 posts since I last got on here.

Can someone summarize what I need/should/could change if possible? And on what boards?

- Matt

I'd like to see an in-line resistor pad (0805 SMD) for the FET gate, possible a pad for a pulldown resistor for the FET as well.  Maybe two versions?  I know that some would like the simplicity of using without any extra resistors or jumpers, but they seem to offer some benefit for some situations. 

Mountain Electronics : batteries, Noctigon, and much more! What's new? 

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0805 resistor between GATE & GND (easy), 0805 resistor between PB1 & GATE (erm, not so easy, at least on the 17mm). I guess all of them using the TO-252 FET need those, the 46, 20, & 17mm.

17DD has the ground pad for pin 5/star 2 over pin 6 instead, just needs a tweak of the solder mask (might already have been done on the rev.2 boards, I haven't looked yet).

SRK FET board could really use a change to the switch input pads, something like this

http://75.65.123.78/blf-srk/switch1.jpg

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I don't think the tiny little FET on the 15DD board needs the resistors, same as 7135s don't need them. I haven't pulled up the datasheet on that FET though.

Mattaus wrote:
If anyone has been financially put out by some of these minor oversights please PM me and I'll replace your boards with new ones for free.

Pfffft, stop that. We're participants, not customers. lol.

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WarHawk-AVG wrote:
Since the PWM of moon mode is like 3-5 of 255 the FET might not be able to open fast enough...thus no current flow

No, the FET will open at lower PWM values than when using 7135s. They usually don't work at 4 or less, the FET works all the way down to 1.

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Matt, got any ideas as to why the SRK & Nanjg PCBs work without the gate/pulldown resistors, but not the 17DD? There's got to be some logical explanation. I think the only trace I didn't test with a bypass wire is the one from PB1 to the gate, but it's probably not that since the SRK one is the same width but about 4-5 times longer.

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Mattaus wrote:

If anyone has been financially put out by some of these minor oversights please PM me and I'll replace your boards with new ones for free.

Mattaus, no worries man!  We are all grateful (at least I am) for all of your hard work.  You don't owe us anything at all.

Mountain Electronics : batteries, Noctigon, and much more! What's new? 

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I'll review the 70N05 boards tonight and see if anything sticks out as to why the 17DD is being such a PITA. I'm guessing no one has tried the 20DD yet?

I'll also make the others changes Comfy mentioned.

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WarHawk, I had 2 star engaged to the PWM leg, grounding out the PWM. Once that jumper was fully removed it worked again.

BUT, I soldered leg 5 to ground and had the same 4 modes, moon wasn’t engaged by doing that. So I don’t know what’s going on there. Took that off and it’s still working fine in 4 modes.

Here’s some numbers for the crunchers out there. This test emitter is, I believe, an XM-L2 T6 3C on a 16mm Noctigon glued to a 1/2” thick copper insert in the HD2010 Aluminum pill. Wired directly to the star and run with my DMM using it’s 6” long 12ga leads with gold plated banana plugs…

Lo to High with rested cells

Samsung 25R @ 4.13V 2500mAh
.02, .43, 2.37, 5.26A

Sony C4 @ 4.16V 2600mAh
.03, .46, 2.45, 5.44A

Efest 35A @ 4.20V 2600mAh?
.03, .46, 2.49, 5.60A

Samsung 20R @ 4.20V 2000mAh
.03, .48, 2.60, 5.70A

Sony C5 @ 4.15V 2600mAh
.03, .46, 2.50, 5.44A

Test cell @ 4.20V 1500mAh
.03, .48, 2.55, 5.69A

So it’s consistent pretty much across the board, with the top performing cells showing their customary margin of lead. I’m charging those cells that were not fully charged, but I expect they’ll be consistent with the others. I don’t know why this FET driver is showing lesser numbers than I’ve gotten previously unless it’s the T6 itself.

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Previous tests were also with a single XML2 on copper?

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Looking at the FET 15 if the Attiny were shifted to the left then C1 R1, R2, and two extra FET gate R’s could be lined up(rotate C1 90 degrees and put the 3R’s parallel to it below) one below the other. This would also allow LED+ to be nudged left and be diametrically opposite LED-. This would put pins 2&3 closer to the ground ring for star connection.

EDIT – Just a suggestion but you might hold off on reworking the 15 until we find out what the limit is on that FET. The K4212 looks very robust and has an extremely low Rds of ~ 3mOhms at 4.5V and is 3.4mm x 3.4mm if we need to change that and might work for the 17mm board.

Digikey page a bunch of options.

Three Tanna leaves to give him life, nine to give him movement. But what if he eats the whole bag?

Scott

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That was with the same emitter set-up but no driver, straight direct drive. In that instance I was seeing High at 6.85-7.18A.

With the Qlite modded FET driver I was seeing 5.87-6.30A from these same cells. So it looks as though the BLF FET board might be running a bit lower than the Qlite FET board.

Edit: Just found notes where my C8 with the big copper pill from Buck and a modified Qlite FET driver pulled 6.66A from a 20R in a built light. Same light with an Efest 35A makes 6.61A and 1673 OTF at start-up, 1497 OTF at 30 seconds. This with an XM-L2 U2 1A.

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You have the two new resistors on this one, right? Try jumping from B+ (or LED+, same thing) to the gate on the FET, see if it goes up when you do that. Also try jumping across just the resistor inline with the gate.

If it shows a big jump with the resistor bypassed it means the gate isn't opening fully when going through the resistor, we may need to look for a different FET that doesn't need the stupid resistors. I have a few of the 2SK4212s I can try, they have a lower gate charge spec.

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Running the 18500 for ease of handling, I was seeing just over 4A on high with zero change both visibly and on the meter when I crossed the positive to the gate. Showing 2.7A on Med/Hi it did indeed jump in brightness and to 4A on the DMM.

Not sure about crossing or bridging the resistor, didn’t see any change there either.

Edit: Trying again to jump the resistor I touched the wrong things and it popped and smoked. I think it’s staying dead this time. I gave it a standing 10 count and they carried it off on a stretcher. It doesn’t look good.

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Rufusbduck wrote:
Looking at the FET 15 if the Attiny were shifted to the left then C1 R1, R2, and two extra FET gate R's could be lined up(rotate C1 90 degrees and put the 3R's parallel to it below) one below the other. This would also allow LED+ to be nudged left and be diametrically opposite LED-. This would put pins 2&3 closer to the ground ring for star connection. EDIT - Just a suggestion but you might hold off on reworking the 15 until we find out what the limit is on that FET. "The K4212":http://www.nxp.com/documents/data_sheet/PSMN2R4-30MLD.pdf looks very robust and has an extremely low Rds of ~ 3mOhms at 4.5V and is 3.4mm x 3.4mm if we need to change that and might work for the 17mm board. p. "Digikey page":http://www.digikey.com/product-search/en?pv1291=1829&FV=fff40015%2Cfff80... a bunch of options.

No, wrong K4212. It's from NEC/Renesas, 2SK4212A. About double the Rds(on), but much lower gate charge. TO-252/DPAK package. The one that comes on the red 'JB-2013-11' driver. That exact part is discontinued/EOL, and the replacement sucks balls, specs nowhere near compatible for this low-voltage-overhead setup. The replacement would probably work fine in a different circuit. The old 2SK4212s are available in bulk still, but only as surplus NOS and only from possibly questionable vendors on aliexpress.

This one looks kinda interesting as a possible substitute: http://www.digikey.com/product-detail/en/AOD510/785-1481-1-ND/3603497

A little bit lower Rds(on), and Qg is much lower and closer to the 2SK4212 that started this whole mess in the first place.

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DBCstm wrote:
Running the 18500 for ease of handling, I was seeing just over 4A on high with zero change both visibly and on the meter when I crossed the positive to the gate. Showing 2.7A on Med/Hi it did indeed jump in brightness and to 4A on the DMM. Not sure about crossing or bridging the resistor, didn't see any change there either. Edit: Trying again to jump the resistor I touched the wrong things and it popped and smoked. I think it's staying dead this time. I gave it a standing 10 count and they carried it off on a stretcher. It doesn't look good.

Hey man, you know what they say: you can't make a driver without breaking a few omelettes... er, no wait...

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Lol, and yes I agree.

Just went out to take the trash down to the road. Carried the C8, M8 and L2P with me. None are throwers. All are FET modded. And wouldn’t you know I saw a couple of critters out at 100 yds that I just couldn’t quite identify even with the big M8, granted by the time I pulled it out they had moved off and were closer to 200 yds away. Might have been a pair of foxes but I haven’t seen foxes around here in a very long time. Nearly 30 years. About the size of a big housecat but with large puffy tails. Had to’ve been foxes. Cats tend to slink away, these did a sort of bobbing lope. Almost took my camera, wouldn’t you know I didn’t! lol

At any rate, the L2P Triple worked quite nicely, very good for a walking light with it’s wider illumination pattern from the 10507. I didn’t use Turbo very much, but purposely ran it on High for several minutes and it was really too bright. The 2nd level, Med, is about right for walking. It shifted levels reliably, never flickered, and all the dust didn’t show any PWM in any mode.

I lit up a Jack Rabbit with the C8 from about 40 yds and he got confused. He came towards the light, unafraid, stopping to nibble a couple of times, but got within about 10 yds of me before I said something to him and he loped off. Still not afraid but putting some distance between himself and this unfamiliar small sun.

The big M8 with it’s MT-G2 can really light up a tree! For anyone checking into a tree at night it makes a 40’ tall tree seem to be in daylight. We’ve lost a couple of trees looks like. Early bloomers and a late freeze caught em. Here we are sitting at 70º at 10 O’clock at night. Walnut tree’s are blooming out, grass is growing (gonna have to mow in the next few days)

Nice night. Smile

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