minisystem
Newly Enlightened
- Joined
- Jul 12, 2011
- Messages
- 96
I got some advice from Kevin @ Lamdalights about putting a LED with a copper heat sink on a screw bulb base. I've used a couple of commercial drop-in replacements in a vintage bike light, but wasn't satisfied with the brightness (but the built-in driver was handy!).
Anyway, I've made a prototype and it seems to be working well. I worried that the thermal performance might not be that great, but it seems enough heat is transferred out of the bulb base and into the socket to keep the heat sink temperature reasonable. It might have been just as good to make this out of aluminum, but I really liked Kevin's method of soldering the LED's thermal pad directly to copper.
Here are a few pics:
Copper heat sink:
Finished bulb with Cree XP-G:
Crude performance data (lux @ 1M with no secondary optics over time starting at ambient temperature, final heat sink temperature in parentheses. TerraLux TLE-1S measured for comparison):
This, of course, will need a separate driver, which I'm still working on. The XP-G can take up to 1.5A, so I'm not going to be over-driving it. Also thinking about using an XML instead as it looks like the bigger package has better thermal characteristics and slightly more light output at equivalent currents.
Anyway, I've made a prototype and it seems to be working well. I worried that the thermal performance might not be that great, but it seems enough heat is transferred out of the bulb base and into the socket to keep the heat sink temperature reasonable. It might have been just as good to make this out of aluminum, but I really liked Kevin's method of soldering the LED's thermal pad directly to copper.
Here are a few pics:
Copper heat sink:
Finished bulb with Cree XP-G:
Crude performance data (lux @ 1M with no secondary optics over time starting at ambient temperature, final heat sink temperature in parentheses. TerraLux TLE-1S measured for comparison):
This, of course, will need a separate driver, which I'm still working on. The XP-G can take up to 1.5A, so I'm not going to be over-driving it. Also thinking about using an XML instead as it looks like the bigger package has better thermal characteristics and slightly more light output at equivalent currents.
