can a Digital LED driver be used as Laser Diode driver??

[supermario680]

Can a digital and adjustable LED current driver be used to control a laser diode?

What about voltages? say if output voltage is 15v with the driver set to 30mA? will it damage the diode? or just automatically adjust?

 

[djQUAN]

some LED drivers can be used, others not depending on how clean the turn on/off spikes are.

The output voltage will adjust depending on the diode Vf to reach the desired current but there are limits. especially if the driver is either a boost or buck topology.

 

[supermario680]

some LED drivers can be used, others not depending on how clean the turn on/off spikes are.

The output voltage will adjust depending on the diode Vf to reach the desired current but there are limits. especially if the driver is either a boost or buck topology.

Ok because the lower limit on the voltage for the relay out is like 7v. With typical forward voltages between 2-5 so that should work out I think.

 

[djQUAN]

what IC is the LED driver and what diode are you planning to use? so we have a better idea of the situation.

 

[Tomorrows System]

Do you have the photo of the driver maybe?

 

[supermario680]

what IC is the LED driver and what diode are you planning to use? so we have a better idea of the situation.

All just theory for now. It's a garadasoft PP610 controller. Adjustable current source with resolution down to a quarter milliamp. I figured it might be good for testing all sorts of diodes with current control that precise. Here's a link to the user manual http://www.ccsamerica.com/pdfs/Gardasoft-PP600_Manualv09a.pdf

 

[The Lightning Stalker]

It looks promouseing. The only way to know
for sure is to test with an oscilloscope.

 

[Tomorrows System]

I think TLS is right, especially that you need to know what is happening during "switch on".

 

[Cyparagon]

It's not a no-name chinese board, and it's a linear design, so without even testing it, I'd say it'll work fine. But you're a fool if you're going to spend $500 on a simple laser driver.

 

[supermario680]

It's not a no-name chinese board, and it's a linear design, so without even testing it, I'd say it'll work fine. But you're a fool if you're going to spend $500 on a simple laser driver.

Really? Wisconsin too? Cool. Anyways i already have the driver and did some testing with a random unknown diode.

Powered it with a 7.5v transformer, measured 7.5v across the load terminals both empty AND with the diode wired in. Also I had it set for 30 mA but measured only 17 with the meter. The diode did light up though.

 

[Cyparagon]

So you're saying the load dropped 7.5V at 17mA? What diode was this? Unless it was a green diode, you're measuring something wrong. If it was a green diode, you need more input voltage.

 

[supermario680]

So you're saying the load dropped 7.5V at 17mA? What diode was this? Unless it was a green diode, you're measuring something wrong. If it was a green diode, you need more input voltage.

A red diode. And no idea. No way to identify it. Very well might be junk but it did light up very dimply. And the point was it measured 7.5v (same as source voltage) at the load terminals regardless if the diode was connected or not. And yes I pulled a lead and measured with my meter in series and it said 17 mA

 

[Cyparagon]

You're reading the full 7.5V on the output without a load, because it's a constant current driver. It will attempt to push more current through the load by raising the voltage, but there is nothing drawing the current. For this reason, you should never connect a load when the driver is powered on. At least not a load you care about.

A laser diode will only light in forward bias, so your polarity is correct. A red diode will drop between 2 and 3.5V depending on the diode, the temp, and the drive current. A red diode will never drop 7.5V. Get a picture of your setup and indicate where you are taking the voltage measurements.

This is fine for goofing around and learning, but if I were you, I would ultimately sell that one and buy 40 laser drivers with the proceeds.

 

[blasterman]

I have 450nm blues running in projectors for a couple years now off of LuxDrive BuckPucks (1000mA) with zero problems. The greater problem is DC/DC LED drivers are are rather rare beyond 1000mA without resorting to more essoteric flashlight drivers, and most of us want to drive blues much higher than that.

AC to DC LED drivers are another matter. They typically have very high CAP discharge levels and tend to pass down unsteady surges as the connect to their load. In this respect I prefer to use a simple Xdrive and run that off a clean but high current 12volt supply. As long as the assembly has some airflow over it and the diode is kept on a beefy sink they run for hours at a time with zero problems. Lab supplies are obviously better for testing due to their adjustability, etc.

 

[LaserCo]

I have 450nm blues running in projectors for a couple years now off of LuxDrive BuckPucks (1000mA) with zero problems. The greater problem is DC/DC LED drivers are are rather rare beyond 1000mA without resorting to more essoteric flashlight drivers, and most of us want to drive blues much higher than that.

AC to DC LED drivers are another matter. They typically have very high CAP discharge levels and tend to pass down unsteady surges as the connect to their load. In this respect I prefer to use a simple Xdrive and run that off a clean but high current 12volt supply. As long as the assembly has some airflow over it and the diode is kept on a beefy sink they run for hours at a time with zero problems. Lab supplies are obviously better for testing due to their adjustability, etc.

On the LuxDrive which model are you using?
AC or DC input?
@ how many volts input?
How many 450nm Laser Diodes, their part #'s & wiring configuration?

and to save me from having to look it up for every 450.. (I assume you already know), is this version more or less robust than the others?

Have you ran the Luxdrives in parallel ?

Thanks for this tip!

Oh, @Supermario680, Yes Hello, WI too!
(Its time to edit my location today I guess)

 

[Things]

I've tried using luxdrive buckpucks for driving diodes too, if you can hook up an opamp to swing your modulation voltage from 0-10V you can feed it directly into the buckpuck for analog modulation.