Pioneer DVR112 laser diode voltage/current specs

Hi,

I'm not sure if this will be useful to anyone else, but I have removed a Pioneer DVR112 laser diode today and measured the current draw over a range of voltages. The diode is an open can version and I left it in its aluminium holder and heatsinked it to a large heatsink while testing. Results are below. By the time I got to the end it was dying and slowly dimming, as would be expected at those sorts of currents.

Re: Pioneer DVR112 laser diode voltage/current spe

Ok why aren't the voltage ratings the same while increasing current?  I would think that would be the best way to find the "knee" on this diode.   I mean if you increase both current and voltage your going to reach the dead curve quicker wont' ya?

Excellent info there though. Great job. it will come in very handy. If I don't blow the next one.

Re: Pioneer DVR112 laser diode voltage/current spe

As the current is increased does the forward Voltage drop also increase?

Re: Pioneer DVR112 laser diode voltage/current spe

Kenom said:

Ok why aren't the voltage ratings the same while increasing current? I would think that would be the best way to find the "knee" on this diode. I mean if you increase both current and voltage your going to reach the dead curve quicker wont' ya?

Excellent info there though. Great job. it will come in very handy. If I don't blow the next one.

Click to expand...

Whenever the voltage is increased going to the diode, the current will also increase...and visa versa...there is no way around this.

Re: Pioneer DVR112 laser diode voltage/current spe

What Gazoo said, the device will plot it's own curve.  If you vary one (current or voltage), the other will vary.  You cannnot choose to run them at x voltage AND y current - you get to choose only one, the device picks the other.  

In addition, if you choose to run the LD at regulated voltage x when the LD is cold it will have a current y.  As the LD heats up, the voltage will remain x but the current will increase to (y+zT).  That's why it is best not to supply LDs with a voltage source.

Kenom said:

Ok why aren't the voltage ratings the same while increasing current?  I would think that would be the best way to find the "knee" on this diode.   I mean if you increase both current and voltage your going to reach the dead curve quicker wont' ya?

Excellent info there though.  Great job.  it will come in very handy.  If I don't blow the next one.

Click to expand...

Re: Pioneer DVR112 laser diode voltage/current spe

As the guys above have said, the laser diodes are like LED's, they're current driven and will draw the current they require depending on the level of voltage available. It took me a while to understand it but after testing several LED's and laser diodes with power supplies that you can vary the voltage and current, it makes sense now

Also, the reason I did this test is because i've been looking at various LED drivers ranging from 300mA up to 1A. The cheaper versions of these are linear regs which drop a certain amount of voltage across the circuitry. I plan to run the circuit with a single Li-ion battery and wanted to see what the minimum voltage a 350mA linear reg needed to output to keep the diode at it's forward voltage. As you can see from the table, the LD needs at least 2.95v to draw 350mA, now I just need to test the 350mA driver at various input voltages to determine how what battery input voltage will keep the driver outputting higher than 2.95v.

The cheaper drivers come in 350mA and 700mA, but the more expensive non-linear drivers come in pretty much whatever current rating you want within reason. If the cheaper one works i'll give a more expensive 500mA one a go... I have a never ending supply of diodes anyway

Re: Pioneer DVR112 laser diode voltage/current spe

I will be testing an AMC 7135. Is this the same one you will be working with? I also have the same open can diode from the same drive.

Re: Pioneer DVR112 laser diode voltage/current spe

Yep, the drivers (from DX) with the AMC7135 regs. I already have several 1050mA versions but i'm awaiting the arrival of the lower current models. I might see if I can remove a couple of the 7135's from my current boards and do the testing today.

Re: Pioneer DVR112 laser diode voltage/current spe

I have one coming from Kenom..it should be here any day now. If you beat me to the testing it would be great..

I have found supplying the open can with 350ma's makes it an awesome burner. The open can came from a LiteOn 20X DVD burner and I was cooling it with TEC. I accidentally spiked it with an amp of current and it turned into a very nice LED.
I harvested a 112D and put it into the module, and when I went to mount it on my TEC my peltier broke.. :'(

Anyway I think all of the open can diodes are the same..and the 7135 should be perfect to drive them with, although I will be trying to reduce the current to try to get it to work with the GB diodes.

Re: Pioneer DVR112 laser diode voltage/current spe

With the tests I did above, I was actually holding the diode in it's aluminium case to the larger heatsink. It didn't feel hot until I got above about 800mA, but even at 1.15A it wasn't too hot to hold. It was obviously slowly dying though.

Re: Pioneer DVR112 laser diode voltage/current spe

Do you mean 1 amp didnt kill it!? WOW! Im impressed!

Max

Re: Pioneer DVR112 laser diode voltage/current spe

I hooked my module back up with the open can and with some cooling from my TEC it runs very comfortable at 420ma's. I limited the circuit to 420ma's intentionally lol. I am beginning to think the combination of the Meredith module and the mounting block for it are enough to keep it cool even running at high currents.

Also I did not notice any difference in the open cans between the LiteOn 20X and Pioneer 18X burners. I believe the output is the same, and the diodes are exactly the same.

According to Hemlock Mike's graph, running it with 420ma's is producing appx. 225 mw's...pretty impressive.

Re: Pioneer DVR112 laser diode voltage/current spe

Gazoo said:

I have one coming from Kenom..it should be here any day now. If you beat me to the testing it would be great..

I have found supplying the open can with 350ma's makes it an awesome burner. The open can came from a LiteOn 20X DVD burner and I was cooling it with TEC. I accidentally spiked it with an amp of current and it turned into a very nice LED.
I harvested a 112D and put it into the module, and when I went to mount it on my TEC my peltier broke.. :'(

Anyway I think all of the open can diodes are the same..and the 7135 should be perfect to drive them with, although I will be trying to reduce the current to try to get it to work with the GB diodes.

Click to expand...

HEHE. He'll be getting one from kenom when he can get to the post office. Sadly my job keeps me durin the hours the post office is open and I don't get a lunch break. I promise I'll mail this off before next week! I will for sure get it out on sat. if not sooner.

Re: Pioneer DVR112 laser diode voltage/current spe

Oh and thanks everyone for the electronics education. I always though you could keep it at a specific voltage and just increase the current. Now I know different. Gazoo. I've just ordered some more circuits and I'll send ya one of these too when I get one!
http://dealextreme.com/details.dx/sku.4451 I'll ship ya more than one if you want.

Re: Pioneer DVR112 laser diode voltage/current spe

Kenom...Did you look at testing that was done on that circuit? It doesn't regulate very well and is terribly inefficient. Sorry to tell you this... :'(

Source Source Emitter
Voltage - Current - Current
1 volt - 530 ma - 110 ma
1.1 Volt - 670 ma - 140 ma
1.2 Volt - 950 ma - 200 ma
1.3 Volt - 1200 ma - 230 ma
1,4 Volt - 1400 ma - 260 ma
1,5 Volt - 1680 ma - 300 ma
1,6 Volt - 2000 ma - 330 ma
1,7 Volt - 2200 ma - 350 ma
1,8 Volt - 2440 ma - 380 ma
1,9 Volt - 2720 ma - 400 ma
2,0 Volt - 2870 ma - 420 ma
2,1 Volt - 3000 ma - 450 ma
2,2 Volt - 3330 ma - 460 ma
2,3 Volt - 3500 ma - 480 ma
2,4 Volt - 3700 ma - 500 ma
2,5 Volt - 4000 ma - 520 ma
2,6 Volt - 4230 ma - 525 ma
2,7 Volt - 4520 ma - 540 ma
2,8 Volt - 4720 ma - 550 ma

Re: Pioneer DVR112 laser diode voltage/current spe

yeah I did see that. I don't rightly care how effecient it is as long as it's stable.