problem with flexdrive??

[JLSE]

Back in the day I purchased 2 of lavas V1 flexdrive kits. One of mine had also made this whining sound as well.

Only one of the drives were doing this and was most likely a p00r soldering job on my part. It was a diy kit all in pieces, and my first attempt at soldering surface mounts.

The harmonics that were present sounded to be coming from the inductor which was most likely not completely mated to the pads.

Though I have never had this problem since, I have never heard this with a 3410. With the 3410, when they don't work, they just don't work...

Though they do get really hot or blow out a cap on occasion, which is why pretesting is important before hooking up a high $$$ LD.

If your driver was shipped in a bubble mailer, the damage to the inductor could very well have happened during shipment. You wouldn't necessarily notice the crack until a piece breaks away..

 

[Morgan]

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.

Hi Phenex,

Sorry for any misunderstanding, but I was posting about the original driver at the beginning of the thread. I'm repairing a laser for Laserboystuart and was posting the findings so far.

M

 

[LamboLuver]

I seem to be having the same problem with my flexdrive. I bought it about 2 weeks ago, but I took it out of the baggie just today for my build. I followed the configuration for the 100-312ma range by removing the end resistor and bridging the 2 connections as shown in the instruction diagram. I wired up my test load (composing of 4 1N4001 diodes and a 1ohm resistor), and used the voltage across the resistor to set the driver to 175ma. I soldered my SF-AW210 diode onto the board, and when I connected my 2 AA batteries to it, the laser works great, but the driver makes high pitch whine similar to the one described here. The driver itself gets extremely warm after just 30 seconds or so of use. Something is wrong here, and I have no clue as to what, as I have double checked and triple checked my solder joints and connections for shorts, etc., but haven't come up with any answer. I would not like to risk my AW210 diode any further until this problem is resolved.

Hopefully someone here with more experience can help

I also PMed this to drlava, but I decided to post it here as well.

Thanks in advance,

LamboLuver

 

[Morgan]

^I'd wait for a response from Dr.Lave first or go open a thread in the new, "Driver", section that has just opened up.

From now on I think that is going to be the place to discuss these sorts of problems.

Having said this, only using 4 diodes would simulate a voltage requirement of about 2.8-3V, (assuming 0.7V drop across each diode and a little for the resistor). An SF-AW210 requires 5-5.5V so it may be as well to reset your driver using 6 diodes of a test load. This should require the driver to put out more volts and may meet your LD requirements better.

Again, wait for Dr.Lava's response but I suspect your driver is struggling to put out enough volts. What are you powering it with?

M

 

[SHIN]

I think you should include the voltage-drop at the resistor in the test load.

It doesn't matter at relatively low current, but higher current causes the significant increase the drop at the resistor and serial diodes(>0.7V). And the temperature worsens the drop.

So drlava suggested using red test load with 445nm. And he said he was using 200milliohm resitor in high current than 1ohm, because of voltage drop at the resistor.

SHIN

 

[Morgan]

Hmmm, having read some more in the, "Driver", section, I'm now not so sure the number of diodes used in the test load is that critical. Have a look here -

http://laserpointerforums.com/f67/common-test-loads-445-diodes-52840.html -

I know it doesn't solve your problem but it's useful info to maybe narrow down what it ISN'T.

M

 

[LamboLuver]

Contacting DrLava was easy and quick, and I have now resolved the problem I was having. I resoldered all my connections to no avail, so I finally gave up working on it for a while. I sat down a couple days ago and decided to get it figured out. I disconnected my diode and connected my test circuit in addition to replacing the whole battery pack with a new one (same batteries though). The current was still where I had set it before, so I soldered on my diode once again. When I turned on the switch to the new battery pack, it all worked. No whine, no problems. I had re-soldered all my connections before, so all I can think of is that the battery pack itself had bad connections. Not sure the cause of it exactly, but everything seems to work now, other than the fact that the diode has a slight flicker when on, but I have no way to prove that it is because of the driver. It could just as well be a bad diode.

I am satisfied with the outcome, as it saved me and DrLava time and money!

Thanks to all who replied as well!

LamboLuver