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bomber315

Tue Sept 05 2017, 01:06PM

Registered Member #43257 Joined: Thu Feb 20 2014, 03:53PM
Location:
Posts: 33

Hey guys, this certainly isn't the typical kind of post for this forum but i figure if anyone is going to be able to explain my problem to my you guys will.

I have a yamaha warrior atv, i have installed 2 of these led lights on the front of it....

all is well with the stock incandescent tail light bulb. i have ran the machine quite a bit and never seen an issue.

But i attempted to get fancy and add a LED tail light also....

After very little run time one led head light popped and then very shortly after that the other also popped... The tail light remained fully functional, although i did turn the lights off quickly because i feared a short somewhere.

I returned home and replaced the blown headlights for the exact same set. one blew within 3 minutes of start up, while idling. I then remembered having issues with too many led lights on a friends atv and i switched out the led tail light for the original. (also switched the blown headlight for an original also) After this the 1 remaining led was fine.

My questions to the forum are... Can you please explain to me what causes this issue? and Can you tell me how to keep it from happening again?

I believe i am on the right track when i say i need to install a resistor somewhere... But im not sure where the correct place would be to protect the whole system from over current.

I plan on probably running the incandescent tail light, but i fear if the filament ever breaks, the led headlights will blow themselves up shortly after. I did do an autopsy on 2 of the 3 blown headlights and found when i put 12v to the leds after the little driver, they all lit. so apparently the on board driver just failed, but now that the water proof case has been cracked it is very little use to me. Also im not a real expert on anything so i am confused why there is a driver inside the lights when they seemed to be just fine with 12v directly to them.

thanks for the help!!!

Attached is a wiring diagram and the all the info i have on the rectifier/ regulator

The stock incandescent head lights are 12v 30w there are 2 of them
The stock incandescent tail light is 12x 3.8w
There are also 2 other small bulbs (neutral and reverse indicators) they are 12v 3.4w for both of them

1504616768 43257 FT0 Warrior Wiring Diagram Copy

Sulaiman

Tue Sept 05 2017, 03:20PM

Registered Member #162 Joined: Mon Feb 13 2006, 10:25AM
Location: United Kingdom
Posts: 3140

... Can you please explain to me what causes this issue? and Can you tell me how to keep it from happening again?
................................................. ...............
Unfortunately there are many possibilities;

Most likely is that there could be high voltage spikes/transients on the 12V supply damaging the electronics
- Put a TVS (Transient Voltage Suppresor) accross the 12V supply near the lamp
(e.g. 1.5KE24CA, or 1.5KE24A(observe polarity, band = +12V))

.... if there are small transients then the TVS will protect the lamp(s)
.... if there are large transients the TVS will fail short-circuit and you will know what the cause is.
Add a fuse (e.g. 5A) between the 12V supply and the TVS//Lamp so that when/if the TVS or Lamp fail, the rest of the electrics are not compromised.

At a guess, your LEDs are wired as three parallel strings of three series LEDs
based on their lighting with 12V direct.
The LED current during your test was limited to [ (Supply Voltage) - (LED Voltage) ] / (internal resistance of LEDs)
when direct-connected to 12V the LED voltages and internal resistances may give a suitable current, at 15V the current would be many many times greater.
So an inverter is built in to allow a wide input voltage range.

IF the ( fuse + TVS) does not help ... report back and maybe someone will have more ideas.

bomber315

Tue Sept 05 2017, 03:53PM

Registered Member #43257 Joined: Thu Feb 20 2014, 03:53PM
Location:
Posts: 33

the LED head lights ran fine for many many hours with an incandescent tail light bulb. it was only once i swapped out the stock tail light bulb for an LED tail light that the head lights blew... i feel if it were a voltage spike it would have been there all along and blown the headlights months ago. Unless the led tail light somehow introduced the voltage spikes/transients... i am certainly still learning this stuff so i could very well be wrong...

im not sure if this particular voltage regulator/ rectifier is "smart" enough, but my theory is that it sees the very low resistance in the led lights as a dead battery and attempts to charge it with max current... or possibly instead of charging the battery, all of the current is passing through the leds to ground thanks again

hen918

Tue Sept 05 2017, 04:18PM

Registered Member #11591 Joined: Wed Mar 20 2013, 08:20PM
Location: UK
Posts: 556

LEDs and incandescent lamps are very different. Your 12V LEDs have an electronic driver board built into them, as the actual LEDs need a constant current source, or at least current limiting. The bit that is sensitive to voltage spikes is the electronic driver. Even cheap 12V LED lamps using resistors to current limit are sensitive to voltage spikes (perhaps even more so) as the LED itself will be destroyed by significant deviation from its operating specifications, as opposed to a very hot bits of wire in a protective gases (essentially what an incandescent lamp is). They just get a bit hotter and a bit brighter and their life expectancy will go down slightly.

Anyway, your 12V feed to the lights probably has a horrible waveform with all kinds of fluctuations caused by the ignition system, which the LED driver really doesn't like. Over the course of several minutes the driver gets hotter and hotter trying to drive the LEDs with an unstable input voltage. As the driver gets hotter efficiency deceases as the resistance of the MOSFET switch in the driver increases with temperature. Eventually, it cannot keep it up (I've seen LED driver board get so hot the components have desoldered themselves!) and the driver IC (which usually houses the MOSFET) goes BANG, and that's that.

The above is speculation by the way. Interference from the ignition system could also affect the driver directly and as Sulaiman says it could be one of a number of things.

bomber315

Tue Sept 05 2017, 05:22PM

Registered Member #43257 Joined: Thu Feb 20 2014, 03:53PM
Location:
Posts: 33

hmmm ok so the led headlights ran fine for probably 100 hours with incandescent tail light bulb. But when the led tail light replaced the incandescent, 3 headlights blew within minutes. I saved the 4th led headlight buy ditching the led tail light and putting the incandescent back in.

You think that was merely coincidence or is the tail light's resistance providing some sort of protection to the headlights?

EDIT: i will try to get a minute to probe a head light lead tonight and checkout the waveform, it should be interesting to see what it looks like. i believe the ignition system (components 9, 10, 11, and 12 in the schematic) likely separate from the lighting/ charging system

bomber315

Wed Sept 06 2017, 12:30AM

Registered Member #43257 Joined: Thu Feb 20 2014, 03:53PM
Location:
Posts: 33

Here is a link to the waveform... I honestly don't know a heck of a lot about running a scope, I just came across a free one. Let me know if you would like to see something different. Thanks again

bomber315

Wed Sept 06 2017, 01:03AM

Registered Member #43257 Joined: Thu Feb 20 2014, 03:53PM
Location:
Posts: 33

.please delete

bomber315

Wed Sept 06 2017, 01:07AM

Registered Member #43257 Joined: Thu Feb 20 2014, 03:53PM
Location:
Posts: 33

1504660023 43257 FT180497 Img 20170905 205319763

attached is a picture of the board(s) they are 3 sets of 3 leds

johnf

Wed Sept 06 2017, 07:21PM

Registered Member #230 Joined: Tue Feb 21 2006, 08:01PM
Location: Gracefield lower Hutt
Posts: 284

Your scope trigger is set wrong
the switches int source coupling the int switch should be ch1 not vert mode.
The level control pot should be at 11 oclock not 6 oclock

bomber315

Wed Sept 06 2017, 08:15PM

Registered Member #43257 Joined: Thu Feb 20 2014, 03:53PM
Location:
Posts: 33

ok thanks... i will post another video in about 2 hours (6pm est)... maybe this winter when im not super busy with everything else ill actually take the time to learn how to use a scope properly... sorry for the inexperience

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