Dead BDR-209

Hi everyone, today I killed a BDR-209 and I'm not sure what actually killed it :yabbem:. I recently got it from DTR (the one with the copper module + driver + G2 lens), I was doing the first tests to see if it arrived ok, in the picture is the setup used.



The procedure was the following:

First I setted the PS to 5V and a maximum output current of 2A, following the indications from DTR's ebay post.

Then turned off the PS, connected the leads as shown, then turned the PS on again. The diode was working alright with the PS indicating that around 1A was being drained, the heatsink was slightly warm I checked with an IR thermometer and it was around 55°C. I kept it on for about 5 min.

After 2 min turned it on again and started to try to focus the beam, checked the temp again and it was still around 55°C. When I focused the beam it started to burn the closet door, so I turned the PS off. Again the laser was kept on for about 5 min.

I retuned with a piece of wood to point the laser, but this time when I turned on the PS the laser dot was dim, I checked the PS and the output current was of 600mA. Then it started to get dimmer quickly until no light can be seen. The final current from the PS was around 22mA. After that the laser won't turn on again.


I haven't done more tests after that, preferred to ask first before making another mess. I read (here) that you don't want this 405 to get even warm becase it will fail. But in that case the diode would've have failed during one of the first two tests instead of the during the start of the third? or maybe a transient from the startup of the PS killed it when I turned it on the third time? but in the case of a transient one would expect an instant death instead of the beam getting dimmer.

I'm not sure about what killed the diode so i would aprecciate any help to figure this out, also any tips for perfoming this kind of test safely in order to avoid killing more diodes in the future. (sorry for any mistakes in my english)

P.S.: I would use this opportunity to thank DTR for the awesome service, the whole module whas carefully packaged with a lot of bubble wrap and it arrived without a scratch, here in Chile packages usually arrive with some sort of damage.

What current was the driver set at?

Did you have the power supply set to a max of 5V or did you only set a max for the current? I know if you feed a higher voltage to a boost driver than the diode requires, the driver can fail. I accidentally killed an X-Boost driver this way when experimenting with a test load a while back. Boost drivers are designed to step UP the voltage, not down.

That's a fast reply :yh:

I didn't touch the driver setting so it should be at 600mA (DTR's default for this pack).
And the power supply is set at constant 5V.

If you had the wires hooked up and then turn the power supply on, it could send a voltage spike to the diode and kill it, I killed one that way. Always turn the power supply on or off before the wires are connected, or after disconnecting them, never while the wires are connected to it.

I thought about the connecting and power on/off order before making the tests, if I connect the driver to the PS with the voltage already in 5V it will still receive some spikes due to the connection bounce.

I suppose it could, if you don't have a driver in series, but I've never lost a diode doing it yet. Where I have killed them is when the power supply swings far above the voltage it is set to when initially powering up. Best to have a soft start circuit between the diode and the power supply, I guess. I'm somewhat new to the hobby, maybe someone can comment with better info. To test your power supply, set it at lets say, for example 5 volts, hook up a peak reading DMM or volt meter which can store short transient voltage spikes and turn the power supply on, if your power supply is much like one of mine, even though the last setting you had the supply at was at low voltage, you will see the supply actually spikes at a much higher voltage when first turned on and its built in meters won't show any indication of it. Maybe your power supply doesn't do that, but the precaution of never turning the supply on when something is hooked to it is a good one with any power supply, I think. You could still have a problem if the commercial power flickers!

Comparing the two approaches I think I'll start powering on/off before conecting, even if it gets some bounce it would still be in the 5V range keeping the input below the boost's output voltage.

Tomorrow I'll desolder the diode and make a test load to check if the driver is still alive.

I had the same laser diode die on me in the same kind of module too, but don't know why, it was running off of batteries. I have not investigated if it was the driver or diode that failed yet, but I suspect I was running it at too high of a voltage using two Li-ion batteries in my laser pointer, need to confirm if that is the problem or not, just haven't contacted DTR to ask yet. However, being you are a student I have a possible solution for you, I have several of those diodes I'm not using as pulls from sleds and am willing to send you one, if you did indeed blow the diode, I also have a simple driver I can send set at 650ma, but it isn't nearly the quality driver you would get from DTR.

These 800-900mw output single mode laser diodes at 405nm are some awesome burners which can be focused at a distance to burn stuff, but the amount of light you can see is very low at only 1 percent as bright as a green 532nm laser diode of the same power output.

I paid 118$ + shipping (don't remember exactly how much) for the whole pack.

I aprecciate the intention :thanks: it's hard to find kind people in the internet, but since I'm in Chile the shipping (asuming the guy you know lives in Alaska) might be as costy as purchasing another diode from DTR.

P.S.: Tried to +Rep you but it didn't seem to work, i think it's still to soon for me to do that. Still trying to get the hang of how the forum work.

No problem, I've worked with some SATCOM tech's from your country, all awesome people... glad to help you... I edited my post some to explain I am the person who can help you and will send at no cost to you, my contribution to help you, I know how difficult it was when I was a student, I had less than ten bucks a week to eat with in 1982, ate lots of oatmeal!

Thanks for the try, but until you have some reps, it won't work.

I don't belive beeing a student today is as hard as in 1982, instead of oatmeal I have tons of noodles

I can't thank you enough for that help, it really made my day (or night considering it's around 00:40 here).

Tomorrow after I check if the driver is still alive I'll PM you all the details.

Peche said:

I'm not sure about what killed the diode so i would aprecciate any help to figure this out, also any tips for perfoming this kind of test safely in order to avoid killing more diodes in the future. (sorry for any mistakes in my english)

P.S.: I would use this opportunity to thank DTR for the awesome service, the whole module whas carefully packaged with a lot of bubble wrap and it arrived without a scratch, here in Chile packages usually arrive with some sort of damage.

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Yea not sure it does not sound like you went over 5.5V so it should have been fine as long as it did not overheat. Send it back to me before trying to take it apart and let me see what I can figure out and do for it to get you back up and running.:beer:

Alaskan said:

I had the same laser diode die on me in the same kind of module too, but don't know why, it was running off of batteries. I have not investigated if it was the driver or diode that failed yet, but I suspect I was running it at too high of a voltage using two Li-ion batteries in my laser pointer, need to confirm if that is the problem or not, just haven't contacted DTR to ask yet.

Click to expand...

Yep if you used two Li-ions in series that will do it. Max input for the driver is 5.5V.

those V spikes can be a bit** I've killed a few diodes forgetting to do something so simple as waiting to connecting the leads

Well it lasted a year and probably 200 uses at 8+ VDC, lucky it lasted that long.

Alaskan said:

Well it lasted a year and probably 200 uses at 8+ VDC, lucky it lasted that long.

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An X-Boost lasted that long at over 8 volts? Mine died almost instantly when the input voltage exceeded the voltage drop of the load by only 1 to 2 volts. That was with only one li-ion. I just accidentally had the jumper one diode too low on my test load.

my power supply looks similar to yours OP. I've found that I have troubles using it to power boost drivers.

I set voltage to zero, then turn current all the way up then hook up my driver, then slowly ramp up voltage.

Michael.