Hello Everyone,
I just spent the afternoon with Brian at Meanwell USA tech support.
He was kind enough to let me go there and take my stuff to be analyzed. I guess I'm lucky 'cause I work a block away from their office.
Well, the result wasn't what I expected.
We found out that the flashing I was refering, happens on all ELN-XX-48 versions of drivers. It doesn't matter if it is 30W or 60W and even version "D" or "P". It's part of the driver design. There is a zener diode that was added only on the 48V version, which causes this issue.
The only solution is going with a different voltage of driver. For example, you could go with the 24V version and have no issues with flashing. You would still be able to drive 12 LEDs at 1000mA, but you would have to rearrange your string to be 2 string of 6 LEDs in series and connect them in parallel. In this case, you would want to go with the ELN-60-24. Just make sure your wire can handle 2A now.
The other thing I found out is that the arduino PWM by itself, cannot be used to control the dimming of the driver. You would have to add a new circuitry to up the output pin voltage to 10VDC. So, even though it is PWM dimming, it still requires 10VDC as the amplitude of the PWM.
I guess not many people knew about this one, huh?
I only found out, because I happended to be measuring the amperage of my string and I was getting only 600mA. When I took my stuff to his lab, he was too measuring only 600mA.
We ended up scoping it and he said that in the specs, even the PWM is 10VDC. I guess I misinterpreted when I read the specs. It is kinda misleading though: "1~10VDC(D type) or PWM controlled(P type)"
Anyway, just FYI for those planning on building PWM controllers with Arduino.
Ahhh....
Almost forgot....
The "D" version has a much lower dimming cutoff. I beleive he said it is about 0.5VDC, which is 5%. Much better than the 20-25% I'm getting with the "P" version. The spec says 1VDC, but he said in reality it is 0.5VDC.
I hope this can help you guys in the future and avoid lots of disapointments, headaches and lost hours trying to figure this out...
Thanks,
RI