Easy OKR-T VV mod
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These pictures don't even come close to displaying how well done this mod is. The fit and finish is unbelievable.
I have a problem with my okr mod. I have use it only for a month. In that time it works just great. and now The volt is stuck at 2.86v. When i turn the trimmer pot it will go to max 4.5v and in second it drop to 2.86v. I have check the trimmer pot and the resistor. it show ok on my multimeter. Is it the okr cip that cause the problem? is it damage? how can i check the cip to see it it still in good condition or have been broken and cannot be use anymore..
iReally needs an advice..and sorry for my bad english
iReally needs an advice..and sorry for my bad english
could just be a short somewhere. id take a close look and make sure none of the wires are touching any of the others.
It could be a cold solder joint. I would hit all connections with the iron and maybe a tiny touch of fresh solder. At the same time verify all wires and their condition.
I can't think of any good way to test the chip itself other than pulling it and putting it into a test circuit with known good components.
Sent from my NookColor using Tapatalk
I can't think of any good way to test the chip itself other than pulling it and putting it into a test circuit with known good components.
Sent from my NookColor using Tapatalk
To limit the max voltage, use a resistor higher than 220 ohms. There is a chart on page 4 of the data sheet - max of 5v would be 268 ohm, 3.3v is 436 ohm etc.
So if I wanted to add a PTC fuse to this circuit when using the 6A OKR would this one be suitable? I think it's within a perfect range, unless I'm a complete idiot.
MF-R300-0-99 Bourns PTC Resettable Fuses
MF-R300-0-99 Bourns PTC Resettable Fuses
this circuit have short circuit protection , you don`t need ptc fuse.Try to make your mods clean and safety, make a good soldering, correctly wiring..if you want to have a long use mod.
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Seems more suitable for a single cell tube mod.
This one looks good. Maybe some others will chime in.
MF-R400 Bourns PTC Resettable Fuses
And it also has about 40% less resistance than your choice.
This one looks decent and gives a slightly higher hold and about the same trip as yours.
MF-S350 Bourns PTC Resettable Fuses
Pretty damn big though, but that may not be a problem depending on your build as it's only 1.1mm thick.
Is that resistance really going to be that noticeable? I'm at work and haven't sat down to plug in the numbers. I was directed in the past and already have ten of the ones I originally posted.
You chose to use a 6A regulator. I assumed that there was a reason for this, then you mate it with a 3A (hold) fuse? My suggestions were for a 4A and at least a 3.5A. What you have will work, I was just matching them to your reg of choice.
It's always nice to eliminate as much resistance as you can. But it's no big deal.
It's always nice to eliminate as much resistance as you can. But it's no big deal.
Well I'll admit it, I guess I was confused as to what this fuse does. After reading that last post Will I realized the hold literally holds the current at the designated "hold" amperage and if it reaches the trip then it will raise its resistance. Right? I thought it would rise until it reached the trip, as opposed to staying or holding at the hold.
All it took was some questioning.
All it took was some questioning.
You are confusing me.
Just look at Holding current as the safe current to run through the fuse. There is no current holding going on as I think you are inferring.
These are strange things, it's not like they all of a sudden trip like a traditional fuse, the resistance keeps getting higher (and they keep getting hotter). Best to keep them in a range where this will not happen. You don't want them 'tripping' or even getting close to 'tripping' as that tends to increase the resistance in the normal state. These are emergency insurance for the worst case scenario.
FWIW no battery we use is truly unprotected (including IMR). Under the positive terminal they all contain a similar PTC (positive temperature coefficient) device like these we are discussing.
http://batteryworkshop.msfc.nasa.gov/presentations/02_Cell PTC Characterization_EDarcy.pdf
As I originally had said the 3A hold sounds right for a single cell mod, where the working amps will always be less than than that, or for a 3A Murata reg, again same reason.
Note this is not the way a Li-Ion's protection circuit works, where tripping of any sort is a disconnection as we know it.
Who knows I could be completely wrong.
Just look at Holding current as the safe current to run through the fuse. There is no current holding going on as I think you are inferring.
These are strange things, it's not like they all of a sudden trip like a traditional fuse, the resistance keeps getting higher (and they keep getting hotter). Best to keep them in a range where this will not happen. You don't want them 'tripping' or even getting close to 'tripping' as that tends to increase the resistance in the normal state. These are emergency insurance for the worst case scenario.
FWIW no battery we use is truly unprotected (including IMR). Under the positive terminal they all contain a similar PTC (positive temperature coefficient) device like these we are discussing.
http://batteryworkshop.msfc.nasa.gov/presentations/02_Cell PTC Characterization_EDarcy.pdf
As I originally had said the 3A hold sounds right for a single cell mod, where the working amps will always be less than than that, or for a 3A Murata reg, again same reason.
Note this is not the way a Li-Ion's protection circuit works, where tripping of any sort is a disconnection as we know it.
Who knows I could be completely wrong.
No, I think you're correct, I'm the one that's been confused. I have a better understanding now. Thanks again Willy.
+1
Maybe this will also help.
I got my hands on a VV box someone else did using this regulator and they had the big fire button on pin 4 (out). They also had the master on/off between the addy and that ground (B-) solder joint shown in this diagram. So the reg was always on at full but w/o a load, drawing that 32.2ma while I slept. Fixed that by moving the mstr on/off switch to before the common ground point and after B-.
I'm fixin' to build another and on this one I'm gonna do like I've done on my 4 pin 5v LDOs and (based on the above diagram) turn that fire button into a master on/off slide switch and put put a 470K resistor off of pin 1 thru a small (50ma) NC switch to ground (B-). Then you don't need the big amp fire button and you'll not be shocking the reg to life at full load every time. IMO, that's how this reg is supposed to work. Quiescing the regulator by via pin1 should drop the reg down into nano amps of current but it's still running between, as Grimm says, 'toots'
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http://www.e-cigarette-forum.com/forum/battery-mods/193434-low-voltage-cut-out-5.html
I've gotten this to work after some trial and error. I had to go all the way down to ~15kohm with the 6amp regulator, but in retrospect, I would have been ok with the 3amp version anyhow...
I've gotten this to work after some trial and error. I had to go all the way down to ~15kohm with the 6amp regulator, but in retrospect, I would have been ok with the 3amp version anyhow...
Well I'm actually a fan of big buttons. You really don't need a NC switch, which tend to be kinda twitchy unless you get a very high quality one. And if I understand your intent, I don't think you need a resistor at all with that approach. You are just pulling the pin to ground, there is no real volts/current involved in either the on or off position (I think... and they had the big fire button on pin 4 (out). They also had the master on/off between the addy and that ground (B-) solder joint shown in this diagram. So the reg was always on at full but w/o a load drawing that 32.2ma while I slept. Fixed that by moving the mstr on/off switch to before the common ground point and after B-.
I'm fixin' to build another and on this one I'm gonna do like I've done on my 4 pin 5v LDOs and (based on the above diagram) turn that fire button into a master on/off slide switch and put put a 470K resistor off of pin 1 thru a small (50ma) NC switch to ground (B-). Then you don't need the big amp fire button and you'll not be shocking the reg to life at full load every time. IMO, that's how this reg is supposed to work. Quiescing the regulator by via pin1 should drop the reg down into nano amps of current but it's still running between, as Grimm says, 'toots'
)Read this carefully.
You can use a normal NO one. You can set it up just like the MV reg if that's the one you are referring to to.
Just pull the pin to ground with a resistor, many values will work, this will keep your reg off. Then come off the positive with your switch. Your pull down, though, has to be a value that in combination with your switch/positive that will allow enough current to the pin to meet the requirements above.
Say we want 1mA when the cells drop to 6.5V, using Ohm's Law I get 6.5k. Theoretically it would appear that when the cells drop below 6.5V 1mA will no longer be available and the reg should shut down. A good thing. But Mamu is using 10kΩ which even at 8V is only .8 mA, but it seems to work fine. Maybe my whole line of reasoning is incorrect.
Head over there for a peek.
http://www.e-cigarette-forum.com/fo...ena-vv-mod-denalis-lil-sis-step-step-how.html
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