I purchased a Magic Shine MJ-858 on closeout. It is the perfect size and weight for me to use as a helmet light for mountain biking, the tradeoff is I find it is not bright enough. I have other lights which are brighter, but they tend to make my helmet slip around and hurt my neck on longer rides.
It originally came with a diffuser reflector, which I replaced with a smooth one I found at Fasttech. It narrowed up the beam which is more to my liking for a helmet light.
I’m wondering if replacing the emitter star will make a significant difference? I’m not trying to over do it, I’d just like to get more out of it without melting my helmet or reducing run time to less than 1 hour.
I don’t think I’m going to find a direct swap for that driver. I’m not equipped for surface mount soldering so swapping out resistors and or ICs might not be a good option for me. I’d also like to retain the original switch if possible.
Any opinions on which emitter and what gains I might expect? Any other ideas?
Stick in an XML2 U3 on copper and you’ll see a slight increase, without current bumping you’ll keep pretty much the same runtime
Also swap out the emitter wires for 20 AWG Silicone wire
Should give you a slight brightness bump
But I do see an R150 which is just itching to be changed!
Yeah looks like XPG with 20AWG silicone wire and XML2 on copper you’ll see a massive increase.
I’m not the best person to ask about resistors, I tend to just bridge them and hope for the best! Maybe stack an R100 on top? I’m sure someone with better knowledge of that will pitch in
If you want to keep the similar runtime but with a brightness increase do what I said above, stacking/bridging the resistor will dramatically reduce runtime, unless you just slightly up the current
I’d say for what you want forget about the resistor mod though!
I have an XM-L2 U3 here, it’s not on a copper star though. I also don’t have any AWG 20 silicone wire. Any suggestions on a good source for that? What could I expect if I run the XML on the stock aluminum star? I guess I could just try it and see?
I can send you some silicone wire for free if you cover postage, and don’t mind waiting for it from the UK, I’ve got copper MCPCBS as well, otherwise I can think of mtn electronics for USA dealer
You should be ok using aluminium but I’d always recomended copper for the better thermal management
I agree with James3 XML2 will give you a nice increase. Appears you have a buck driver. Not sure increasing the thickness of the leads will boost output, but it will help increase efficiency. Thicker wires make more of a difference in situations where voltage overhead is close to load.
You should be fine with an aluminum base. It actually will probably help with output at stock current levels. Djozz did some mcpcb testing that you can look up to be sure. You say you are not set up to reflow. So that works out nicely for you (assuming your XML2 is already mounted on aluminum).
You can find thicker wires at most hardware stores and on old retired equipment like car stereos and such.
Thanks 4Wheeler, yes I can solder, but not reflow. I think James was suggesting specifically silicone 20 AWG I have PVC 20 AWG here already. I had a look in my parts bin and I think I have everything I need to make this into an XM-L on copper or an XM-L 2 on aluminum. I’m not sure which I’ll use yet. Seems like either one will work well.
