I bought a 9 led off road light from Amazon a week ago. Curiosity got the best of me and I opened it up to see which LEDs it was using. It seems to be powered by outdated xb-d q-5 or r-2 bins. I plan to upgrade all 9 of them to xml-t6’s. I noticed when I opened this light, which is meant to run off a car battery with a 30 amp fuse and a relay, has some sort of driver/board. I know that each of the current emitters are meant to be driven at 3.5v, the same as the xml-t6’s i plan to upgrade them to run at the same voltage.
I’m not experienced with circuit boards, but can somebody with more experience tell me what exactly this board is doing? What the microprocessor looking chips and those 3 copper coils are doing? The driver seems to have 3 of each. What do these numbers mean? Is there a place where I can buy these same chips and make my own, similar board? I included a labeled/non-labeled picture. The light runs from a car battery source, and its default output is 1550 lumens (from the box).
Leds need regulation of current, a slight change in voltage will cause a big change in current, so just regulating voltage is tricky, that is what the electronics are for. Apart from a different way of mounting them (you will need individual support boards under them to mount them here), to make full use of XM-L's (say 9x~600=5400 lumens) you may need more current than this board will deliver. In other words: you might have a big project ahead (and 9 XM-L's are not cheap either)
Ah, so what you’re saying is that, without the proper board, it won’t amplify my xml-t6’s to it’s optimal lumen output?
I’m making a list of terms and things to read up on as I type this thread since I’m not that versed yet with the electrical terms, (not too sure what mA means, etc. etc.)
The box on the lamps say:
Wattage: 27W
Operating Volt: 10-30 Volt DC
Current Draw: 1.9A@12V, 0.8A@24V
Volts: 9-28
(not really sure if it’s possible to tell without having the board and a multi-meter at hand) Let’s say I were to remove the old bin and solder new xml-t6 emitters successfully, how many lumens would I be able to power each xm-l t6’s knowing the technical data I posted above having to do with wattage/amp draw?
It looks to me like you have three different individual circuits with each one powering three leds in series, probably a buck circuit. Input voltage around 13v and led vf around 10v (not sure about that leds vf) for 3 leds in series. That means from there specs the current would divide between each circuit from the suggested current draw. Each circuit is receiving 13v and 1/3 the total current, the three circuits are probably in parallel to the source. At 13v the current draw is probably closer to 2 amps. So divide that by 3 and you should have .666 amps per circuit and that’s what each led is seeing in the 3 series array. In series the current stays the same the voltage divides. In parallel the current divides the voltage stays the same. Just my guess, I could be wrong. You would have to test it with a DMM to be sure.
apt323, you are correct on the type of leds it’s using. i didn’t note any rectangles in the led, so i figured best bet was one of the cree q’s or r’s that don’t have the rectangles in them. at the 1500-2090 lumens these lights are rated at, you’re more than right. here’s is a link to the product i bought. http://www.amazon.com/Light-Power-Tractor-Round-Degree/dp/B007ZGBLNW/
moderator007, damn, I was really hoping to get the 600-900 lumens xm-l t6’s can be driven to. i was planning to buy nine 16mm t6 emitters from dx.com for $10 each and soldering them replacing the old ones. the led’s currently on, say they can be driven to 3w on the link apt323 provided. in my mind i was thinking that because 3w X 9Leds, being 28 watts, the 27 watt from the product description was providing each led 3w. and 3w to mA (using an online converter), being 3000mA, that i was going to be able to drive each t6 to it’s maximum output at 910-975 (cree wiki datasheet). the tech data on the box of the light reads;
Wattage: 27W
Operating Volt: 10-30 Volt DC
Current Draw: 1.9A@12V, 0.8A@24V
it doesn’t seem worth it spending $70 for 9 led’s for an extra 50 lumens per led, knowing the t6’s aren’t even gonna run at their optimal lumen output lol. i learned a lot from this thread about how some of the circuits work. i guess my next step is to learn more about circuits and hopefully one day, put something together to drive t6’s to their maximum output in this same array. the housing being die cast iron with heat sink patterns on the back, it sure seems like the perfect housing for a high powered diy project lamp. i’m not giving up yet, but i got a lot to learn and read up on.
I have no idea what your vf of those leds are, maybe around 3v at .666 amps.
P = Power(Watts)
V = Voltage
I = Current
V x I = P
3 x .666 amps = 1.998 watts to each led
.
If you want more Watts go with a new driver. George may have a one driver solution (Hyperboost).
You can contact him through his site. Hyperboost Technical
You could mod the sense resistors to get some more current. The PT4115’s can do 1.2A, but 1A is probably more realistic. PT4115’s are actually a fairly decent buck converter chip. I used PT4115 drivers in these and a couple of triple Nichia 219 wall wash floodlights:
The problem you will have adding XML’s is mounting and heat sinking. XML mod is probably not too practical.
Maybe you could just try and upgrade with bridgelux leds they are better then cheap chinse versions (if that is what is currently in the light) of that led.
I have to agree. This is probably the cheapest easiest solution. If those are 3 watt leds you could increase the current by changing the value of the sense resistor to give you more current at the led, more lumens.
I = .1/RS
RS being the current sense resistor. A R100 should give you 1 amp to the led.
PT4115 current is set to approx. 600mA, each driving string of 3 led’s (approx. 2W per led) With typical car voltage this setup is very efficient (over 90%) but those generic chinese leds are not so efficient and replacing them with something more decent will increase amount of light dramatically. Resistors marked R160 can be changed to increase current to led using 0.1/R formula but in order to keep decent efficiency I would use 0.12R resistors at most.
