problem with current mBoostdrive&mFlexdrive

[DasGeraet]

Hello,

im new to this forum, so be gentle
I tried to search for my question, but didnt find a good solution, so i made a new thread.
If got one of the popular 445nm diodes and wanted to drive it around 800-1000mA. So i ordered a micro flexdrive and a micro boostdrive. I don't want a portable solution, so its no question of what batteries i use, i decided to save money and try a power supply. I have:

- a 0-30V 0-3A adjustable one
- a fixed 5V 1,6A one
- a fixed 15V 5A one with a small 7805 circuit
- 4 AA Batteries

So i soldered the bridges for the -1400mA range on the flexdrive (took ESD precautions with wristwrap). Here is a picture after the soldering:

Then i connected the driver to my laser diode and measured input voltage and output current. I adjusted my source to 5.4V and tried to change the pot. It worked and the current increased, but only to around 500mA, then it began to make a high frequent noise and dropped to ~300mA (or was it my supply?). After lowering the current, it could be increased again. When the current dropped, the input voltage decreased to 4.1V, and i adjusted it back to 5.4V. Now i was able to increase the current to ~600mA, but then the drop occured again. I tried the other supplys, but always the same. Whats going on here? How can I fix this?

Later, after a few more trys, the small metal disc of the pot fell off, so i cant use it any more, picture:

Can someone tell me what pot is used here? perhaps i can solder a external one in place ...

Later I tried the boostdrive, and here the result was worse than with flexdrive. I soldered the bridges, picture:

I started with 3.5V (its a boost drive, so ...) and the max current was around 250mA, which i could change around 10mA with the pot. With higher input voltages, i reached ~400mA, but then I was at the max input voltage according to the manual. The output voltage was always too small. Here, i also tried other supplys, but nothing worked.

Please help and tell my how i can get this working better (yeah, 600mA is bright, but it can go better ...).

Thanks in advance and sorry for my not so good english.

Greetings,
DasGeraet

EDIT: oh, sry, images are larger than i wanted them to be.

 

[Isoleucine]

Wow. Your photos stun me. I wish I could take macros of SUCH beauty. oh.

Anyways, to the main point. The pot on the flexdrive is something you might not find commonly around electronic stores locally, but the best solution is to contact the DIRECT seller of these drivers, aka. "drlava" on these forums. He sells these on this forum directly form his website, and other people buy them there, like modwerx and cajunlasers and so forth. I read a story a while ago, and I think you can ask drlava to sell you the pot for a sum of cash. Im not sure how much he will sell it to you though.

IIRC, someone here mentioned that if you do short these drives for any amount of time, it can cause permenant damage to the drives to be careful. If you have shorted them in any manner, I suggest you go talk to drlava directly to find out, again, he is the designer of these drivers.

Futhermore I havent worked with PSUs of any sort, Im just a student hobbyist. I have also noticed that 4AA batteries push the driver over its limit, which is something you do not want to do. According to the manuals, you must imput a voltage no more than 5.5 volts for the flexdrive or boostdrive to operate. If you have done so, you may have damaged the driver. If you want to operate the drivers with a battery, use only 3 AAs, not four, or you can try the popular 18650's or similar li-ion batteries that output 4.2V.

Lastly, you should re-read the manuals if you have not already. They give you all the cool details on driver operation.

I have a few comments. I assume those fibers on the flexdrive are of cotton or similar material used to deflux the boards, right? I personally use alcohol swabs and they work nice. Great soldering work there, and I hope that you placed the switch in the right positions.