It would appear from feedback on the CPF and MTBR forums that the bastid light makers have listened to and addressed some of the issues in the early lights . and they are shipping with thermal paste and screws holding the led in place and other improvements suggested by some folks .
but here is a report from a guy Who makes the best led drivers out there
so knows what he is on about .
So, I received one of these lights to evaluate. Anyhow, here's my summary after an hour or so of running various measurements.
Cheap construction and incredibly poor thermal path from the LED/Driver to the body of the light.
The driver outputs around 2.4A on high and around 0.84A on low. Regulation appears stable over time and temperature.
The inductor just 'hangs' in space on its leads - that is NOT a good plan for long term reliability as the light bounces around. Those leads will eventually snap. At least pot that part of the circuit down.
The next thing is that the thermal path from the driver is pretty poor. I mounted the brass PCB 'holder' into a support to see how hot the driver electronics would get to versus the brass ring/support. After about 10 minutes the driver was at 75C with the brass ring at 30C. I'm guessing there would be an even higher temp differential with more time. This shows a poor thermal path from the driver to the brass ring.
Now, if we factor in ambient temperature in the housing due to the LED heating, then that poor driver is going to be up in 100C range in very short order. I hate to imagine what the junction temperature of the FET and switcher IC are at.
So, given that the driver shares the same thermal path as the LED that driver WILL cook over time - if the inductor doesn't snap off first...
Anyhow, I certainly wouldn't want to use the light long term and rely on it as it stands. Even beefing up the the thermal path from the LED heatsink to the body of the light will only address keeping the LED somewhat cooler - the driver board is still going to be cooking.
So, in summary, you get what you pay for. The light package is relatively inexpensive, but there's a bunch of thermal issues that haven't been well addressed and some electronics issues (floating inductor and PCB thermal path to the brass ring).
cheers,
george.
The whole thread is here
http://www.candlepowerforums.com/vb/showthread.php?t=232163
so you can be informed by the geekiest light people on the planet.
Its £50 for a light /battery / charger and works OK cheap enough to bin and buy another next year when it packs up .
you have got to go with your budget and wants / needs.
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