[ale] More on LEDs...

[Neal Rhodes]

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-
> 
> 
> 
> --
> 
> Sent from my Android Acer A500 tablet with bluetooth keyboard and K-9 Mail.
> Please excuse my potential brevity if I'm typing on the touch screen.
> 
> (PS - If you email me and don't get a quick response, you might want to
> call on the phone.  I get about 300 emails per day from alternate energy
> mailing lists and such.  I don't always see new email messages very quickly.)
> 
> Ron Frazier
> 770-205-9422 (O)   Leave a message.
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