Any major issues I should be careful about reflowing an LED? Is there a best way to reflow?
I have the h40 in hand. the above review said the bezel was easily removable by hand, but mine doesn’t seem to do so. i’ll try heating it up and loosening it
Before reflowing, be sure to remove the plastic centering ring around the old emitter. The best way to reflowing is to gradually bring the emitter up to temperature like with a cheap electric hot plate. Some have used small torches to rapidly heat the MCPCB up, but that’s not really ideal. Be sure you have liquid solder for the new emitter as well as new thermal paste when you go into removing and replacing the MCPCB, the board with the emitter on it.
It looks like you can get that emitter on a 10mm-16mm MCPCB, if you don’t feel comfortable with reflowing, you can buy on already on a board with the same dimensions as the old and do a straight forward swap.
Totally, my first successful reflow was pretty exciting to say the least. Forgot to mention, be sure to get the anode and the cathode side of the bottom of the LED lined up correctly. It’s not as big a deal in this case if you end up reflowing the the emitter with opposite polarity as you can simply reverse the neutral and live from the driver on the board.
Do you think the luminus cube 1800K could swap onto the acebeam h40 driver running off of 1.5V AA? I’m guessing it has a boost driver, with my very limited knowledge, since it takes lithium ion, NiMH, and alkaline?
I’m looking at the product datasheets for the LEDs, but I’m still too noob to tell. They don’t list a minimum forward voltage for the luminus cube. also the footprint of the SST20 looks like 3535 vs the 1616 of the cube.
I’m guessing it won’t since the 1616 probably won’t hit all the contact points on the driver?
The H40 is already pushing the 3.4 volts needed to drive a Luminus Cube. The Cube’s forward voltage should be nearly the same as the SST-20 in practice. Manufacturers sometime list forward voltage as V (f).
You could do the same mod mentioned in another thread that makes the center pad the negative while the old negative becomes a second positive. That mod, however, may make the driver go haywire as most of those DTP paths are not fully electrically isolated. Then there’s also the forward drive current. I’m running one Cube at a max of 700 milliamps. 4 Cubes should be able to handle 2.8—2800 milliamps— amps safely.
If you wanted the next closest thing that will also fit in a 3535 footprint without the use of a filter, you can use the Cree XP-E2 PC Amber. CRI is there in the 40s, and it doesn’t render blues. Or you could use the Lee daylight to tungsten series on the SST-20 to achieve a filtered warm white LED with better CRI then the PC Amber, but more of an amber tone.
You could also use the Epileds golden yellow LED. Djozz has 4 in a BLF Q8. That has a CRI in the 60s, but it needs a 5050 footprint to work.
to measure amps in a flashlight, do you just put a probe on the end of the battery while in the flashlight and the other probe on the battery tube exposed metal?
gotta figure out how to get a luminus cube to work! it looks so cool. although those other options might decent.
You have to make sure your voltameter can test current, amps. I found out that me cheapo Green-Lee can’t measure current. Ideally you would want a clamp style ammeter to test tailcap amps. Have you tried looking around at the spec. sheets for the H40 to find its forward drive current? That would be easier.
would be nice to have a spec sheet