Lava Micro FlexDrive Driver (lavadrive2) fits pens

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

The black thing, thats what I unsoldered and I think soldered back on backwards and proberly broke it too!

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

pullbangdead said:

Hey, Dr. Lava, my iron slipped and there is a little component that is now no loner on my v4 flexdrive.  It's the small one next to the + diode contact, indicated in this photo.  Do I need it?  If I don't need it, can I short across it? leave it open circuit?  Please advise, hoping I don't have to reattach it properly to make the driver work.

Thanks.

Click to expand...

That part is important, you will need it unless you are driving a blu-ray then you can leave it open circuit I think.  

leuko, when you solder blob connected to the part behind the negative pad, that is a direct short across the output, and will pop the driver chip. This was why I pointed this area out in the do's and dont's a few posts ago. As far as component spacing, yeah it's tight but that was necessary to achieve the new size. If I extended it from 12mm to 13 or 14mm but then it wouldn't fit in some existing designs...

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

Open circuit for blu-ray maybe, and get it back on there if I want to use red, got it, I think.  We'll see what happens.  It may just be trashed, I'm now confused on how the order of events went when I was working with it; I got some solder around it without realizing, and tried to power a diode and it didn't work.  I then found another problem connection that I thought was causing the lack of power to the diode, fixed that, and then realized that I may have been shorting across that component while powering it, but I'm not certain; and then when trying to fix the component in question is when it came off the board.

Oh well, I'll see what I can do with it.  Thanks.

ETA: I put this driver away and finished the leadlight build with the 2nd driver I had on hand, and it's working great; LOC in the leadlight, ~430 mA or so (with short duty cycles).

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

drlava said:

[quote author=pullbangdead link=1209418066/992#998 date=1240179383]Hey, Dr. Lava, my iron slipped and there is a little component that is now no loner on my v4 flexdrive.  It's the small one next to the + diode contact, indicated in this photo.  Do I need it?  If I don't need it, can I short across it? leave it open circuit?  Please advise, hoping I don't have to reattach it properly to make the driver work.

Thanks.

Click to expand...

That part is important, you will need it unless you are driving a blu-ray then you can leave it open circuit I think.  

leuko, when you solder blob connected to the part behind the negative pad, that is a direct short across the output, and will pop the driver chip.  This was why I pointed this area out in the do's and dont's a few posts ago.  As far as component spacing, yeah it's tight but that was necessary to achieve the new size.  If I extended it from 12mm to 13 or 14mm but then it wouldn't fit in some existing designs...
[/quote]


So the driver is dead?   Wow, what a serious waste of $26.   This damn thing is worth more in it's weight than platinum...

Would be nice if you gave some warnings in the OP or on the driver purchase page.  I mean I realize it is common sense not to do these things, but when you have less than 1mm of space to solder with, it's going to be a common mistake.  If I had realized the severity of it I would have taken a lot longer to get the solder right.   And that's fine and dandy you posted somewhere in this 32 page thread about this, but come on man... a warning of some sort about this in the OP or purchase page would have been greatly appreciated.   Not all of us are extreme building professionals who know how many atoms exists in this driver.   A brief warning of "Hey, don't accidentally get any solder on any of the small pieces surrounding all the connection points, otherwise you will destroy this beyond fragile driver."    Whats next?  Am I going to get one of these to realize it will break with the oils from my fingers when handling it? Heck, for all I know it will become useless when it's exposed to oxygen...

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

^To be fair to lava, he says many times, everywhere, that putting power to the driver with a short circuit output would break it, that's the only reason that he says you HAVE to use a test load (unlike the LM317 or rkcstr drivers which, strictly speaking, will still limit current even with no load).  The biggest writing on the whole instruction sheet is "Warning: This driver is a current source mode driver. Do not operate it without a load or with a short circuit output, damage to the driver may result."  

As long as it wasn't powered on while the short-circuit was in place, it should be ok, as well.

Looking at your photo and at the driver itself, you can see the traces, you can see that shorting to that component inbetween the contacts will short across the contacts themselves, and you can do a continuity test with the contacts and components.  Before ever powering on the driver, I ALWAYS do a continuity test on everything.  For the Lava drive, I make sure there is continuity from the diode negative pin to the negative battery contact to the negative input contact on the driver, since these are all continuous.  Then I also ALWAYS test to make sure the positive and negative diode pins are completely isolated, especially on the lava where a short across the output will kill it.

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

Just sent you a PM for a 420mA preset flexdrive. Thanks!

ryan

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

A short should not harm a constant current driver, at least not quickly. And in fact I just had one yesterday: the wires connecting the diode to the FlexDriver V4 got twisted so much that they connected at the diode. In the beginning I didn't know whether the diode was dead, or the battery, or what else was going on... so I took the module apart and finally found the problem. I untwisted the wires, put in a bit of tape for additional protection, reassembled everything... the light is back! In effect, I was running the driver with the output shorted several times for periods up to maybe 10 seconds.

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

pullbangdead said:

^To be fair to lava, he says many times, everywhere, that putting power to the driver with a short circuit output would break it, that's the only reason that he says you HAVE to use a test load (unlike the LM317 or rkcstr drivers which, strictly speaking, will still limit current even with no load).  The biggest writing on the whole instruction sheet is "Warning: This driver is a current source mode driver. Do not operate it without a load or with a short circuit output, damage to the driver may result."  

As long as it wasn't powered on while the short-circuit was in place, it should be ok, as well.

Looking at your photo and at the driver itself, you can see the traces, you can see that shorting to that component inbetween the contacts will short across the contacts themselves, and you can do a continuity test with the contacts and components.  Before ever powering on the driver, I ALWAYS do a continuity test on everything.  For the Lava drive, I make sure there is continuity from the diode negative pin to the negative battery contact to the negative input contact on the driver, since these are all continuous.  Then I also ALWAYS test to make sure the positive and negative diode pins are completely isolated, especially on the lava where a short across the output will kill it.

Click to expand...

I have/had it connected to a test load, and I checked continuity (resistance) between the battery end negative all the way down to the test load negative and it was reading normal. But as lava said, it popped some cap (whatever the heck that means), so I am SOOL. I will try later to make sure there is not any contact anymore.

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

A cap is a capacitor :

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

PMed for another one preset at 420 mA

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

Hey lava i have a question, when i try to test my driver on a load and i shorted the two resistors for 108-420mA current i get a whining buzzing sound that's really high pitch, and i cannot get a reading over the test load, do you know whats happening?

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

Check it with a good magnifying glass, you probably got solder where it doesn't belong.

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

I checked, no shorts... Is it a defective unit?

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

Not likely. Close-up photos, please!

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

I would post pics but i can't get any that are clear, trust me there is no soldering shorts, all of it has been cleaned off. Could i send it back to you to see if you can fix it and please set it at 200mA? I would really appreciate that if you could.

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

drlava I sent you your payment via paypal a few days ago. I just want to make sure that you got it and everything was there. I sent you a few pm's but you haven't responded. No big deal. Thanks man