problem with flexdrive??

an inductor is a wire around a ferric core right... So a coil of wire wrapped around it pulsing with current will make it vibrate. Kinda the same principal as a speaker. I know for a fact some video cars will squeel and it is due to the chokes in the power circuit.

Here is a case of it here. NO MORE GTX 280 SQUEALING! Nvidia’s “Deadly” Flaw and How To Fix It - Nvidia - Graphic-Displays

KiLLrB said:

an inductor is a wire around a ferric core right... So a coil of wire wrapped around it pulsing with current will make it vibrate. Kinda the same principal as a speaker. I know for a fact some video cars will squeel and it is due to the chokes in the power circuit.

Here is a case of it here. NO MORE GTX 280 SQUEALING! Nvidia’s “Deadly” Flaw and How To Fix It - Nvidia - Graphic-Displays

Click to expand...

Hmm, good explanation,
I just figured it would be nicely fixiated so it would not vibrate.

Looks like it depends on quality of the coil... and Nvidia is not making a name for itself right now...

In this case, we're speaking of a big difference in frequency ..... 1,6MHz for the normal working frequency, and some KHz for the resonance ..... this resonance can be caused from a broken inductor, but also can be caused from defective working cycle of the switching too (the driver don't have 500 or 1000 uF of output capacitor like the big switching circuits, and as current-regulating laser driver is also working in a non-normal configuration, after all, so, yes, it can happen)

HIMNL9 said:

In this case, we're speaking of a big difference in frequency ..... 1,6MHz for the normal working frequency, and some KHz for the resonance ..... this resonance can be caused from a broken inductor, but also can be caused from defective working cycle of the switching too (the driver don't have 500 or 1000 uF of output capacitor like the big switching circuits, and as current-regulating laser driver is also working in a non-normal configuration, after all, so, yes, it can happen)

Click to expand...

My LM3410X has 1.6 MHz, but
10uF input
10uF schottky output
20uF diode output capacitance.

No sound what-so-ever.

And what about the chargers?

its the 18650 kit from jayrob, ive heard of the flexdrive making weird noises though.
it might be because the flex was momentarily operated without anything on it when the diode leads came loose from the driver leads. just a thought though.

btw it wouldnt be because of high current as its set to 380mA.

stuart

TPS 63010 used in the flexdrive is a bit more critical than the 3410 .....

BTW, sorry, i just realized that i gave a wrong data, the normal working frequency of the flexdrive is 2,4MHz, not 1,6 ..... sorry, my error

The problem with the high pitched tone ended after i putted in fresh batteries.
Instead my laser flashed up like hell and ended becoming a LED :scowl:
Okay, 200€ thrown outta the window.. but i wanted to know the reason why and checked the driver.
Looks like it blew up?



You can see the top cover of the inductor shattered.
What could make this happen? Is the forward voltage at 410mA with a 12x diode too high? I blew up 2 drivers with it, tho the first one ended up with resistors getting so hot that they just jump of the pcb, don't know why that happened, but my diode wasn't harmed when this happened.
What do i do wrong? I'm very experienced with electronics, i even use a smd soldering iron and wear esd shoes when i do soldering or touching the electronics...

Looks like it was the inductor. Looks like it was resonating to shatter like that.

That is not the "top cover" that is part of the ferrite core of the inductor ..... without part of it, your inductor now is less than its nominal value (3,3uH), so the chip, also if still work, cannot work correctly at full current (but i cannot guess what's the actual limit, cause i don't know what exact value your inductor have at the moment, sorry)

And yes, this can cause more instability too .....

was the inductor chipped or did it have any missing pieces befor it blew ?

The inductor is very brittle and I have chipped one with light pressure before, just not that bad.
I find it hard to believe that resonance can cause it to shatter like that, though. It looks to me that the driver was handled roughly.

It sounds like you have a short somewhere. The driver should not heat up like that.
From the looks of it, I would just trash that driver and get a new one to start over.

Also, the Flex cannot be expected to be reliable at >5.5Vf and >350mA current draw.
At that point it is beyond it's operating parameters.

It was fully intact before it shattered, except there was the high pitch tone coming from it.
And no pressure at all was given to it..
Other ppl drive their 12x with even higher current and their drives are still alive..
Maybe im just unlucky getting drives with bad parts...

Hi All,

Just thought I'd add my 2 cents as I'm going to be repairing the original laser mentioned in the thread title for Stuart.

The laser in question is a Jayrob 18650 kit with the, 'Hot Option', which includes a preset Flexdrive, (380mA). All was good with the kit when it arrived as Jayrob's work is exemplary. Stuart installed his LCC diode, which I supplied preinstalled in an Aixiz, but at some point after that connection was lost between the diode and driver. This, it seems, is where the driver has sustained some damage. Stuart then sent it to me to install a new diode with the knowledge the driver may be unuseable in it's current state.

I have to say that I was a little confused initially by the behaviour of the driver when I received it. The first thing I did was hook up my testload to check output. All seemed fine. I got a steady 380mA output. I did however notice the mosquito whine coming from the driver. I have heard this myself before with one of my own Flexdrives but only ever when being driven by low voltage below the shutdown threshold. Having seen a steady output I hooked up a diode I knew to be healthy and... Instant LED. All connections were sound; no shorts or any other signs of electrical problems. Battery was checked beforehand, 4.1V, so no problems there either. So, I checked the output again with a testload. Same readings, bang-on 380mA. I checked the battery with a similar setup of Flexdrive and LCC, absolutely no problems. Could I have been mistaken about the health of the diode? Maybe, so I hooked up another, fresh from the sled... Instant LED. At this point I contacted Dr-Lava and Jayrob to see if they could help. In the mean time I took the laser to meet with an oscilloscope to see if there was anything obvious on the trace. Voltage, when running my testload was between 1.25V and 4V in a nice steady sinewave giving an average of around 2.75V which is pretty much what I expected to see. Not being an oscilloscope with a, 'Record', function I was not able to review the switch-on portion of the trace but there was a noticeable spike of over 5V, (how much over I couldn't say), and thought this might be the problem. Whilst this test was being done Dr-Lava had replied saying that the high pitched whine indicated problems with the control mechanism of the driver and these oscillations were a bad sign probably due to damage incurred when being powered with no connection to the diode. The suggestion being not to use the driver. (I have passed on the observations of the oscilloscope test and await feedback.)

[edit] Feedback from Dr-Lava is that there should have been no sinewave at all! This driver is clearly done for!

In short, it would seem the whining driver is the culprit having been damaged as described above. This is not good news for Stuart of course and should be seen as a cautionary tale but at least we know the cause. He will, however, soon have a working laser on it's way to him as I will replace the driver for him and install a new diode. My thanks to Jayrob and Dr-Lava for the help and support they have given. Their products are fantastic and I can't fault their service! Great build quality throughout.

To Stuart, enjoy your laser, it will be with you soon...

Any further input is welcome.

Thanks,

M

top noch mate

stuart

Morgan said:

In short, it would seem the whining driver is the culprit having been damaged as described above.

Click to expand...

Why wasn't there any whining the like the first 3-4 seconds turning the laser on? After 3-4 seconds it started whining and the beam got less intense..
I can upload a video if you don't understand what i mean (sorry for my english )
Btw: the driver was hooked up to a diode or testload whenever i put electricity on it.

It probly didn't make the whining sound right after putting the battery in because the battery had a high surface charge that went away in just a few seconds after current started to be drawn from the cell, and that is why the whining started because the voltage dropped, when the voltage dropped the regulater drew more current to make up for the loss of voltage and that is what caused the whine, higher current draw and possibly a loose winding on the coil, the other reason is the driver could be bad ! IMHO.

pHeneX said:

Why wasn't there any whining the like the first 3-4 seconds turning the laser on? After 3-4 seconds it started whining and the beam got less intense..
I can upload a video if you don't understand what i mean (sorry for my english )

Click to expand...