I ordered a few resistors that came today and they were 1/8 watt SMD’s and I need at least 1/4 watt. With a few through-hole style 1/2 watt resistors I’ve started a new chart. As is from the factory I get on three fully charged Keeppower 26650’s 5200 mah. It drew 3.04 amps off of full batteries and climbed to 4.54 amps when it shut down at 9.6 volts. With a 1 ohm 1/4 watt resistor I got the following chart. All voltage checks were done without load.
at 10.15 volts the fun starts in about one minutes running time the amps runs from 6 to 8.9 at that point the voltage sag hits about 9.5 volts est. and the low voltage safety kicks in. More to be posted as I get the resistors in.
I recieved a few more resistors today and added a 1.8 ohm 1/4 watt SMD in addition to the already added 1 ohm 1/2 watt resistor. Light was cooled between each measurement for the readings.
I’m happy at this level and will just wait to see what Mountain Electronics can come out with. She really starts to heat up faster as the voltage drops.
Thanks for the update. Those are some very respectable numbers you just cranked out. Congratulations on your results! :bigsmile:
Richard is putting together a FET driver for my TR-J20 by modding an SRK FET driver for the task. I will still need to shim the driver with copper to fit the driver cavity, rewire the emitters 3S4P with 22 AWG silicone wire and wire mod the tail spring. He really went overboard in answering all of my questions… just as any true lumen junkie would/should. What a great guy.
I considered stripping the TR-J20 driver for a contact plate but didnt want to waste a mediocre driver that I might be able to use for something else in the future.
Ive been inspecting my back yard with the “Chunkster”, just in case an intruder needs a good skull bashing. Id be afraid to crack the sidewalk if I ever dropped it.
If I had this wired to my car then I’d say 10-12 amps would be great. I’m a little concerned about the tail switch holding out and battery endurance. This light would have been much better as a 9-18650’s or even 6-18650’s as opposed to 3-26650’s or 3-32650’s. Justy a little switch change out, 9-18650’s tube and this would become a very do able 100-120 watt light. Maybe the Trustfire TR-J21 will hit these issues.
I’m already looking at taking the top half of the head and making an offroad light set up. Sorry guys those 50-100 led light bars look just hideous. 12 led 4” heads look much better and small enough to mount in front off instead of on top of the roll bars. Currently looking to design 6 of these heads attached to an Aluminum finned plate that molds over the front half of a 3”roll bar to bleed off all that heat through the heads, mount plate and steel roll bar. Lenses will be replaced with acrylic lenses if I can find them. But I degress, for now I’m trying to squeeze the most out of this light for a future project.
Nooooo! Dont turn that gorgeous beast into a car light. After the wire mod (and no other solder to reinforce traces, etc), Richard reports +15A at the clicky with no signs of failure. Its a true beast with those type of numbers. We discussed a forward e-switch solution but it would sit up far too high to be convenient and be placed on the lower sink fins… which is :Sp.
If you want to roll your own car LED light, go to the recycling yard and yank out a few large heat sinks from the bins to build on. You’ll find a huge variety of all shapes and sizes to spark your ideas.
You can also check my light bar thread for ideas and an automotive driver source.
Added two 1-ohm 1/2 watt resistors in parallel. Current hit 4.84 amps and as it went up slowly in the first few minutes the three MOSFETs became roasting hot. The upper limit of this board just got exceeded. Went back to 1-ohm and 1.8 ohm in parallel and everything went back to just toasty hot. Wish this board could take more and it probable would but “POOF” is just around the corner as it plunges to lower voltage/higher amps prior to low voltage cut off. The TR-0262 seems to be the board of choice for these Chinese made 12 LED lights. A fet driver looks nice but I would like to try a few other options like finding out if MOSFETs could be stacked like 7135’s. I really would prefer to keep the light as well regulated as it is now, just twice as bright. I’m not even sure the traces can handle the loads but hey that’s what it’s all about.
Input current isn't truly relevant until the driver efficiency is known - higher input could just be turning into heat, it's the output that really matters. Input current is useful only as a check that the driver is behaving well and not exceeding what the cells/springs/switch can safely handle. You could be getting a false picture of if the resistor changes are actually making an improvement or not.
In other words if you get the same light output with a resistor combo that gives you 6 amps at the tail and with resistors that give 4.5 amps at the tail, obviously it'd be silly to try to run it with the 6A combo.
What a great guy.
Id be afraid to crack the sidewalk if I ever dropped it.