Ive worked on alot of electrical things like lights, motors and RC stuff, but never messed with these tiny circuit ones, got one thats a good candidate, solid built light, but the output just isnt worth a hoot, and it was cheap, so i have it apart now trying to learn what i can, from my limited looking up i see the resistors are what needs messed with, Matt from Lumencraft did a video on a Maglite doubling the output by adding a resistor on top of another, i asked him about mine and he suggested i join the forum and post up..
Its a Vastfire with 3 l.e.d. glass lens, cast aluminum reflector, big heat sink fins and thick barrel, takes two 18650 batteries with an extension for one more, light output didnt change so i will stick with justtwo batteries, in the photo you can see the R200 and R100 resistors that i can only assume is whats needed working on, the jumper wire at the bottom right, whats that for ?
It’s bridging the connection where an MCU would typically be.
I’m assuming you only have 1 mode, On/Off?
A MCU would typically provide different modes like, Low/Med/High/Strobe but it would also provide LVP(Low Voltage Protection) and thermal management.
How warm/hot does the light get after you’ve run it for a while?
What batteries are you using with it?
Doesn’t get hardly warm at all after 30 minutes. And yes one mode..
I have the batteries that came with it in it now (1200mah non protected 18650) but tried Streamlight SL-B26 2600mah and Samsung 35E in it..
Its very comparable to my Streamlight TLR-1 but supposedly is 3800 lumens.. i knew that was gonna be a lie, but was disappointed at how low it was..
Now my Streamlight Protac 2.0 HP gets HOT on high just after a few min but lights up my whole property.
How is the cooling of the LEDs?
The head not getting warm can mean thee things, either, the cooling is very good, the LEDs are not driven too high, or the LEDs have near to none thermal contact to the case.
Cheap lamps usually have the latter. They only get warm on the outside because the air underneath the LED has heated up so much.
So before thinking about cranking up the current, make sure, the LEDs are cooled properly!
It had thermo glue, l.e.d. has a nice thick heat sink back, its just not putting out enough power to heat things up, if i had to guess its no more than 500 lumens at best.. that with a large heat sink head it never gets warm..
Like i said this is surprisingly well made, just low on power.
Its cheap enough id suggest you guys getting one to play with, for the price id highly recommend it, just know its low output..
If you replace the R200 with another R100 that should increase the current output by roughly 1/3.
I’m sorta guessing here but I think the sense resistors are 1210(3.2mm x 2.5mm)
Without an MCU you have no Thermal management nor do you have additional modes that you could switch to, if you felt the light getting too hot.
What size is the driver PCB in mm?
The MCPCB in your light is aluminum.
In enthusiasts lights we typically use Copper MCPCBs with DTP(Direct Thermal Path).
What that means is, the center pad on the bottom side of the led is soldered directly to the copper core of the MCPCB.
This allows the heat to be transferred quickly away from the led.
On an aluminum MCPCB the center pad of the led, is soldered to a thin copper trace that is electrically and thermally insulated from the Aluminum core of the MCPCB.
The heat will transfer to the aluminum but it does so much more slowly than it would on a Copper MCPCB with DTP.
That said your light has another potential major design difference from an enthusiast light.
In your picture I can see the Coil:
This leads me to believe that there is no thermal shelf(solid metal) below the MCPCB.
If that’s true, the MCPCB is only in direct contact with the light around the outside edge.
This will not provide good thermal transfer between the MCPCB and the body of the light.
All this said, if you provide more current to LEDs and the thermals can’t keep up, the LEDs will eventually burn up.
This is what we want it to look like under the MCPCB. Lots of bare metal to allow for quick heat transfer:
Driver is 1.025" and L.E.D. heat sink is 1.75"
Ill just see about replacing this stuff with better, these resistors are a bit small for me to try and deal with..
26mm is not a very common size, so options are limited.
I think this driver might be a good option for you:
I know the factory one was able to do it, but how hard is it to solder on a spring without damaging the driver ?
I think it would be pretty difficult to kill the driver soldering on the spring.
What soldering iron do you have? How many watts is it? Does it have different shaped tips?
Ive got a 60w and a 20w… both with the standard pointed tips.
Got another 20w with a chisel tip but thats for working with plastics only..
Non lead rosin core solder, small bottle of liquid flux of some sort, seems to work soldering leads on batteries. But i can just as easily do it without.
Thank you for the link, i will definitely make an account with them.
If you can solder a lead onto a battery you should be fine.
I will also be looking for a 1.75 or abouts copper disk to put on the back of the led heat sink, be nice to have the shelf lathed down the amount however thick the copper is.. like you said the more contact with the head and cooling fins the better..