AW: [DML] LED Center Console Burnout

["Elvis Nocita" <elvisnocita@xxxxxx>]

Hey Robert,

what kind of LED's did you use ?
Are those non automotive LED's with integrated current source or
resistor ? Then your are breaking one of the basic electronics laws
that says - always use a resistor to limit the current thru a LED !

I know that some cheap LED flash light still do it without resistor,
but they work with batteries of about 3V that can't deliver much more
current than the LED would be able to handle. But on a 12V system you
definitely need the resistor ! A LED is not a bulb, it's a diode !

little example: if you drive a 12V bulb with 12V or 14V (with or without
engine running), the current will be around 15% higher at 14V.

LED: if you drive it with let's say 3.3V or 3.4V, the difference can be like
1000% !!!!!!!
This is why they burn very fast without resistors in series to it.
(again - only if it hasn't it already integrated !)


Elvis



> It is always the four top bulbs, never the three on the bottom. >
>

I'm no electrical engineer but I have wired LEDs before. I just installed
four, 3.5V white LEDs for my licsense plate ilummination and it looks
awesome. It sounds like the four bulbs that keep burning out are doing so
because of a slight over voltage to those lights.  LEDs are pretty sensitive
to power spikes as well. Their life-span will be cut drastically if the
voltage is constantly a couple of volts over wht the LED is rated for. Heat
will also cut into their lifetime.  What voltage are the white LEDs you're
using? Compare them to the red LEDs you have.  What's the difference in
voltage requirments? I use super whites that are rated at 3.5 volts each. I
can run four lights in 'series' conntected to a 12volt power source.  That
way I have a built in buffer of 2 volts for the four lights, running the
lights in an underpowered condition (they will practically last forever that
way).  I haven't installed any LEDs in my instrument cluster yet so I don't
know how they're wired.  You might need to install some resistors to cut
back the voltage going to those LEDs a little. Better break out the
multimeter.

Lingo #2034








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