Yea over 8W is way more than I would expect so it is probably right that more current was getting to the diode than it should. I set these to 4.5A unless asked for a different current. I would agree the best guess based on what you described without seeing is some type of issue with the driver. I can get you swapped out but please shoot it over before taking it apart so I can better troubleshoot it if you have not already.:beer:
It is too early to say that they are all getting stronger. If your LPM is calibrated then certainly yours is a higher than normal diode. ATM, I would say that you have a more efficient diode. But with testing, we may find that the diodes are more efficient now than they was. What current was yours set at? 8W from a single diode.
Haha actually, my girlfriend came home from work, i told her to stay away from the office without safety glasses, and in doing so I shook it off a little bit. No it was still cool and running fine, I just assumed it's only going to drop due to heat, and I was after a max mW for a customer.
After trying a few Ebay Drivers that I was not happy with I have decided to use a Blackbuck 8 to get this thing going again.
Some of the Ebay ones are very poor indeed. One rated at 5 amps would have melted if run at 5 amps for more than a few seconds. And it was unstable as hell at 5 amps. The output was drifting about 0.5 amp. It was able to run well at 3 Amps after I installed heatsinks on the switching transisitors. Doubt I will be using this one.
Another I ssumed was a switching regulator turned out to be an Analogue Regulator. It would have needed a Huge heatsink to run off a 3 Cell LiPo.
I wanted the driver to have a continuous rating so I have done some good heatsinking to it. I still have doubts this driver can actulay run at 8 Amps for very long. Even at 4.5 Amps the Driver chip and Inductor got quite hot. That was with a full copper heatsink on the bottom of the board. I ended up thermally bonding some copper straps from the Regulator IC and the Inductor back to the main heatsink. The heatsink is the heat Spreader from an old Pentium CPU I pulled appart.
Running for only a few minets the copper heatsink gets quite warm. At 4.5 Amps this driver does generate a lot of heat. I will thermally bond the copper heatsink to the Aluminium heatsink in the host which should then run nice.
I have added the 10k pot so I can adjust the diode current from 0 - 4.5 Amps. The Current regulation is VERY good on this driver. From cold its reading 4.50 Amps. After a couple of minets running it had drifted up to 4.53 Amps.
Some Pics of the driver before I assemble it into the host.