Hi,
I'm new to this forum, lots of great info here and a nice community. Maybe someone can help me understand the error in my ways that led to a dead LED (M140) and maybe spare some others from the same fate.
My first attempt to drive the M140 was using a home built circuit based around an LM350 set up to deliver ~1A constant current. That worked pretty well actually, but it wasn't overall a good fit for my application.
So next I tried using an off the shelf driver that looked good by the specs (PDF attached, LUXdrive A009 made by LEDdynamics). This seems perfect for my application, high current, high efficiency (i.e. less waste heat) and easily dimmable.
I used a 100K pot in parallel with a 15K resistor between the dimming inputs, and verified with an ammeter and dummy load that the max current was about 1.5A. Next I tried some high power white LEDs and finally the M140.
As I ramped up the current the M140 failed suddenly at about 1.1A. One person in the know suggested that this driver is for regular LEDs but not suitable for laser diodes (which are more sensitive) and that I post a question here.
So I'm wondering if anyone here has had similar experiences or any insights into why this combo failed when it looked good on paper. I'm not dead set on using this driver, but if there are some tricks to making it M140 compatible that'd be great to know too. Otherwise, I'd just be happy to understand what went wrong and hopefully avoid a repeat.
A little more info on my setup that might be helpful:
Power supply was 12VDC/1.8A wall wart with 6ft cable.
A009 driver was wired to power supply
Diode outputs wired to M140 with ammeter in series
Dimming was controlled by 100K pot w/15K parallel resistor (to set the max current)
One possible clue, the A009 doc says to use a 100uf bypass cap across the power supply if the power leads are several feet long. Also, the whole 'testbed' made liberal use of alligator leads, about 12" and the doc says that the driver and LED should be as close as possible.
It's tempting to try again using a bypass cap and shorter leads, but as these diodes don't exactly come cheap I'd feel better if I had more to go on than a hunch
Thanks in advance for any advice, caveats, explanations, theories and all that good stuff!
Cheers,
Joe
I'm new to this forum, lots of great info here and a nice community. Maybe someone can help me understand the error in my ways that led to a dead LED (M140) and maybe spare some others from the same fate.
My first attempt to drive the M140 was using a home built circuit based around an LM350 set up to deliver ~1A constant current. That worked pretty well actually, but it wasn't overall a good fit for my application.
So next I tried using an off the shelf driver that looked good by the specs (PDF attached, LUXdrive A009 made by LEDdynamics). This seems perfect for my application, high current, high efficiency (i.e. less waste heat) and easily dimmable.
I used a 100K pot in parallel with a 15K resistor between the dimming inputs, and verified with an ammeter and dummy load that the max current was about 1.5A. Next I tried some high power white LEDs and finally the M140.
As I ramped up the current the M140 failed suddenly at about 1.1A. One person in the know suggested that this driver is for regular LEDs but not suitable for laser diodes (which are more sensitive) and that I post a question here.
So I'm wondering if anyone here has had similar experiences or any insights into why this combo failed when it looked good on paper. I'm not dead set on using this driver, but if there are some tricks to making it M140 compatible that'd be great to know too. Otherwise, I'd just be happy to understand what went wrong and hopefully avoid a repeat.
A little more info on my setup that might be helpful:
Power supply was 12VDC/1.8A wall wart with 6ft cable.
A009 driver was wired to power supply
Diode outputs wired to M140 with ammeter in series
Dimming was controlled by 100K pot w/15K parallel resistor (to set the max current)
One possible clue, the A009 doc says to use a 100uf bypass cap across the power supply if the power leads are several feet long. Also, the whole 'testbed' made liberal use of alligator leads, about 12" and the doc says that the driver and LED should be as close as possible.
It's tempting to try again using a bypass cap and shorter leads, but as these diodes don't exactly come cheap I'd feel better if I had more to go on than a hunch
Thanks in advance for any advice, caveats, explanations, theories and all that good stuff!
Cheers,
Joe