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
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