[ale] More on LEDs...

[Ron Frazier (ALE)]

Hi Neal,

I didn't know that.  Very interesting.  Sounds like faulty lamp driver design to me, although they obviously want to prevent massive overloads.  However, leds should only pull about 1/5 the wattage of a standard bulb, so hopefully the ecu will be happy.

Sincerely,

Ron



Neal Rhodes <neal at mnopltd.com> wrote:

>Attempting to steer the off-topic at least back to the concept of
>computers.........
>
>Actually one should be somewhat careful regarding messing with
>tail-lights - it could stop your engine.    No, I kid you not. 
>
>If you go the other direction - bulbs which draw MORE power - you can
>risk a scenario where you are pulling more amperage and you drop the
>ECU
>(there, I said computer) voltage below what is expected to run the
>engine. 
>
>Classic example is hooking up a trailer with lights to your car.  
>
>Stock Sprinters are known to quit running when this is done.
>Winnebago actually puts a relay on the brake light circuit, and runs
>the
>rear brake lights (and trailer lights if connected) off the relay,
>rather than risk sucking too much draw off the ECU circuits. 
>
>Moral: you mess with the fragile compooooter in your car at your own
>peril. 
>
>
>On Fri, 2013-08-16 at 15:10 -0400, Ron Frazier (ALE) wrote:
>
>> Hi all,
>> 
>> I'm learning more about what you can, and cannot do with leds.  I
>discovered the tail light in my car was out.  The car is a Hyundai
>Santa Fe compact suv.  It has a combined brake light and tail light
>which uses a dual filament bulb, an 1157.  I found the 1157R led bulb
>at autozone and put it in the car.  The bulb was barely visible at all
>when the brake pedal was pushed, although it did turn on.
>> 
>> It just so happens that this car has a very complex reflector
>mechanism that's designed to take light from all directions around the
>bulb and channel it to the rear.  It also had a shield in front of the
>bulb which prevents light from going directly to the rear, presumably
>for the benefit of other drivers.
>> 
>> So, the ONLY way the light can get out is to go to the side and
>bounce off the mirror.  The replacement bulb that autozone had
>essentially had 10 or so conventional leds in an array on a flat
>circuit board.  Almost all of its light output is directly to the rear
>and very little to the side.  So, with the new led bulb, my brake
>lights were almost invisible in the day time.
>> 
>> Oh well, I'm back to edison style bulbs, and, unfortunately, they
>work much better, they just don't last long.
>> 
>> Sincerely,
>> 
>> Ron
>> 
>> 
>> -snip-
>> 
>> 


--

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Ron Frazier
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