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-   -   8030 light kit failure? (http://www.rccrawler.com/forum/traxxas-trx-4/615646-8030-light-kit-failure.html)

jimyoung2 02-13-2020 11:09 PM

8030 light kit failure?
 
noticed out of the box the 8030 light kit didn't really dim via the switch on the light bar. Then tonight the lights went from bright to dim to bright to dimmer then to dimmest and then gone for ever over the course of 5 minutes. Multimeter'd the 3v traxxas transformer and got .56v dead consistent. did I waste 90 bucks or is this a fluke?

(battery fully charged, did not damage in any way, using hobby wing brushless system which was fine for about 30 minutes of run time before this failure)

JatoTheRipper 02-14-2020 07:30 AM

Re: 8030 light kit failure?
 
Contact Traxxas. They should replace them if they failed. They have good customer service.

amigaman 02-14-2020 02:14 PM

Re: 8030 light kit failure?
 
The power supply block is known to fail often.
Sometimes even with thermal effects. Most work, but the fail rate is way too high, far higher than anything industrial would accept.

If it weren't for the crappy design of having all LEDs without resistors on a 2.85V supply i'd say you'd be better off building your own resistor block and power the whole stuff from a BEC.
The light bar has like 30 LEDs all in parallel, so has around 2.9V @ some hundred milliamps, no way to do that with a resistor on 6V BEC.
All the other lamps have only a few LEDs in parallel if at all and work well with standard resistors.
The failure is the power supply having slightly above 2.85V, thus increasing the LED current because there are no resistors and you should never ever connect LEDs without resistors to a voltage regulated supply.

The only solution is to return at least the supply block and hope to get one that has a slightly low voltage.

jimyoung2 02-14-2020 06:13 PM

Re: 8030 light kit failure?
 
Quote:

Originally Posted by amigaman (Post 5998447)
The power supply block is known to fail often.
Sometimes even with thermal effects. Most work, but the fail rate is way too high, far higher than anything industrial would accept.

If it weren't for the crappy design of having all LEDs without resistors on a 2.85V supply i'd say you'd be better off building your own resistor block and power the whole stuff from a BEC.
The light bar has like 30 LEDs all in parallel, so has around 2.9V @ some hundred milliamps, no way to do that with a resistor on 6V BEC.
All the other lamps have only a few LEDs in parallel if at all and work well with standard resistors.
The failure is the power supply having slightly above 2.85V, thus increasing the LED current because there are no resistors and you should never ever connect LEDs without resistors to a voltage regulated supply.

The only solution is to return at least the supply block and hope to get one that has a slightly low voltage.

wow that's a lot of info, traxxas warrantied me the power supply but being that this one only lasted a week I'm wondering if this is going to be a problem, add a resistor some how?

amigaman 02-15-2020 02:00 AM

Re: 8030 light kit failure?
 
One single resistor won't do, especially if you plan to change brightness with the light bars switch.

With a bit of electronics knowledge you'll notice the lamps are almost all separately wired to the distribution box, and so a bunch of resistors (one per lamp) may give you better results, with the resistors replacing the distribution and power boxes.
Also, it opens up the possibility to use an rc switch to have the lights come up remotely controlled instead of always on.
But the lightbar has a bad circuit and a resistor on it will get hot because of the light bar having lowest possible voltage but very high current.


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