Led replacement bulbs

Not much inductance comes into play on a DC circuit...

I replaced the high level brake light ones in my 9000.

Yes the filament failure is triggered but another set that i bought to replace the brake lights were supplied with load resistors to fool the filament sensor.

I have to say though that the ones advertised as brake lights are only as bright as normal 5W tail lights once behind the red lens. I bought the ones with the additional sideways LED's which do illuminate the reflector better but they're still not that bright and I haven't permanently fitted them.

David.

Oh... well I didn't know if SAAB had something watching it as it first comes on or something? Guess that would be more expensive and not needed vs. watching the resistance. Actually I was thinking about taking these little tiny (expensive) dashboard lights toward LED's

-meld

I too have been tempted (for a Volvo 440 of Aug 95 vintage). The major problem is I am inclined to have all the dash bulbs changed at the same time, to take advantage of the not-negligible cost of exposing the inner workings then putting everything back, yet how do I find out in advance exactly LEDs form a complete set? Bulbs in a dashboard are unlikely all to be the same type, surely? (Ok that was rhetorical; if I get serious I shall ask in a Volvo NG.)

-- Andrew Stephenson

Thanks. I did wonder about the brightness, i guess i'll just stick with filament bulbs for the present.

bought

If you're talking about exterior signal lamps, the LED replacements are crap. They're dim, have poor optical distribution and most certainly aren't certified for road use.

The only ones I kept were the four high level brake 501 replacements. I got some hyperbright ones comprising 6 LED's per 501 replacement and for an extra brake light, i figure that there's some benefit whilst not getting rid of the main filament bulbs.

David.

If I may tack on here, are there any replacements for the H7 headlight bulbs that have a reasonable lifetime? I seem to go through one every six months. I keep spares, but I had to change on in the rain on Saturday night. I *never* needed to replace a bulb on my Honda.

"Long life" types of H7 bulbs are available. The downside is less light output.

High output types are also available. The downside is shorter life.

More details about bulb lifetime are available on my homepage: <

>

One 0.33 ohm (50W) resistor used to drop the voltage to both H7 bulbs will lower the voltage enough to drastically increase the lifetime without lowering the output too much and still keep the halide cycle going.

On October 7:th, 2001, I replaced my H7 bulbs with high output, short lifetime, bulbs. They get full voltage with light switch in the right position (night time driving) and reduced voltage (with 0.33 ohm resistor) in the left position (daytime driving). I'm still using the same bulbs now, almost three years later.

Better than using a resistor would be a chopper circuit to reduce the duty cycle. You can make one with a power mosfet with sufficient current rating and a 555 timer chip. Lots of electronics info out there on the net.

Why is it better?

• The chopper solution requires more parts and more parts means less reliability.

• The power loss in the resistor (about 25W) is easily taken care of by attaching it to the large heatsink (the chassis of the car).

• The wasted power is power that would have been used had the resistor not been used, so the rest of the car sees no difference.

• Having a chopper pulsing 9 amps creates an low frequency AM transmitter that emits signals both through the air and through the 12V wires. What effect will that have to the electronics in the car?

I like high tech solutions, but for this application I find that the power resistor is a better solution.

Yes but a resistor is a pretty brain dead and reliable fix no?

I heard that during the space race the Americans spent millions developing a pen that could write in zero gravity..... the Russians used a pencil.... ;)

Actually, urban fairy tale. You can check it out here:

Disclaimer: This post should not be construed as a suggestion that the US Gov't would not do anything (everything) in the most wasteful and irrational style.

LOL. That myth was probably started by some liberal. I understand that the Fisher Pen Company

and takes exception to that piece ofhumor. They are very proud of the fact that they developed the pen that theastronauts used in space and development was done at no cost to the USgovernment. They also point out at the US astronauts used pencils before they had the Fisher Space Pen.

Sorry.. I stand corrected...forgot I was on the Saab newsgroup for a moment..

With all due respect to another Saaber, I don't believe that such stories are the source of one political type or another. FWIW, I heard that story first from a very conservative, ex-marine, classified military hardware engineer.

Pointing out the inefficiency of the US Gov'ts operations is an American pastime not associated with any specific party/leaning.

That was a very somber response to a lighthearted remark. So I might as well point out, with all due respect to another Saaber, that pointing out inefficiency of the US Govt. isn't just an American pastime, since the original comment in this NG was made by someone from the UK.