DB-25 ILDA breakout board

[mccarrot]

Hi, I use a die4drive driver connected directly to the QM with a 2 meter ILDA cable.

before I used the Easylase to control the laser and used this combination for a year without any problems.

Now with the qm.net when I turn off and turn on the system 6 diodes allready died.

Maybe the QM.net gives a high voltage out when switching off.

So I probbably I need a 5.1V zener to protect the input, but with a optical isolated board everything is protected.

[DZ]

Hmm, interesting. Well the output does go high momentarily when the QM2K looses power. I've seen that with the card I have in my PC, so I'm sure it also happens when in the .net. The question is whether it exceeds 5V, which I doubt, but I will test here and see. What type of diode are you using, how is the die4driver powered and where on the ilda cable is it connected?

edit-also, the color board I'm working on will feature a 5.1V zener to protect the output.

[DZ]

mccarrot, on power up, the output of the color lines doesn't change at all. When power is lost, the output, at least on my board, jumps up to about 4V then decreases slowly.

[mccarrot]

Did you measured the voltage with a scope?
With a multimeter you are not able to capture a spike.

And even if this voltage peak does not goes above the 5V it is dangerous, because when I power down the QM the lasers will give a static beam out of the projector.

Now imagine the folowing,you are at a rave using 10W laser. Now the fusebox of the QM.NET contollers gets powered down. now there is a change a static beam hits the audiance

I Know Hugo removes a capacitor from the QM.net board. not sure why he does this.

[DZ]

It was measured with a scope.

You are correct, and it can be dangerous to have this happen, which is why I never power off the computer before I power off my projector. Though if it happens inadvertantly, then.......

That is taking this issue in a different, though very important, direction. Unless your board is outputting higher than 5V, then I don't see how the QM2K could be causing your diodes to fail. Where can I find out more information about this die4driver thing?

[Lasernerd]

Now imagine the folowing,you are at a rave using 10W laser. Now the fusebox of the QM.NET contollers gets powered down. now there is a change a static beam hits the audiance .

Always use BEAM blocks!

[Anthony]

Where can I find out more information about this die4driver thing?

http://www.die4laser.com/dvd-rec/Die4Drive.htm

[mixedgas]

either way, its being used wrong.

Steve

[Pangolin]

I've said it before, and I will say it again. I question the wisdom of using a product for which the first three letters spell "Die".

If I were the person who made this laser diode driver, and someone reported laser diode failures to me, my response would be only two words -- "told you"...

As many of you have seen in our LASORB power point presentation:
http://www.pangolin.com/_Files/LASORB.pdf

...in our own research into laser diode drivers, we found that most of them are really really bad. Yes, we evaluated this Die 4 Driver too and... it's terrible.

A 5.1 volt zener, or some other form of protection is a very good idea on a laser diode driver. In fact, people should understand that voltage spikes can come from anywhere at any time, which is why protection is needed for the laser diode.

When we first started looking into laser diode drivers, we did not have the intention to come up with LASORB. Really that was a complete side-effect of our research. Our intention was to come up with an "Advanced Laser Diode Driver" (that was the name of the project). So, for me, "Step 1" of this development was to figure out how to protect a laser diode. We looked at all of the laser diode drivers commercially available, including those from famous companies like Coherent and Wavelength, and ones sold on eBay, as well as hobbyist drivers. Much to our surprise, not a single company on earth had solved "Step 1". So we figured out how to do it, and now we offer this as a product. In fact, if LASORB was used on this "Die 4 Driver" it would solve the problem (and solve a whole lot of other problems too).

Regarding blowing six diodes, I hate to make light of the situation, but can anyone remind me the definition of insanity? Perhaps "Laser Insanity" will field this question .

Anyway, there are a number of easy solutions to this problem. And, Mccarrot, there is someone pretty local to you who knows more about laser diodes than probably anyone else on this board. I am speaking of Uncle Worm, who can no doubt solve your problem in a matter of minutes. Please contact him and see if you can get his attention (should be able to) and then you will be able to solve this, and other problems, with minimal effort.

Bill

[mccarrot]

I allready talked to Uncle Worm on the phone.

He told me the same thing you did, lazorb is the only good way to protect your diodes but is not availeble yet......

I will add a 5,1 zener diode but this will only give me limited protection.


Bill,
Hugo is removing a capacitor from the QM.NET, do you know why he does this? will this solve the voltage output when powering down the qm's?