nib writes:

TOMJ:

I like what you did there. I should have my order of LED's 12 V direct replacements for the 2721 bulbs in tomorrow

So I can let you know- I hope if they work in the instrument stuff- ie. defroster, rear wiper, sunroof etc. I tried those with the 5mm 3.7V 20Ma 2600mcd Radio Shack LED - the view angle is supposed to be 30 deg. but as you say - really did not help much in those switches

But in the window switch they look really great so I would pay the extra $$ for the blue. I have to say that the red in the BMW was never my favorite color.

What size are the LED's you installed and what size are the resistors ?

I will try and borrow a digi cam so I can post what I get up with.

Peace

Hi,

I'm also thinking of replacing all the lamps in the switches around the gear shaft for blue ones. Will look nice in combination with my chrome shaftboard frame.

The thing about standard LED's is:
- Available in 3mm and in 5 mm sizes
- Forward current depends on type from 1 to 20 mA
- Voltage across LED, depends on color from 1.8 to 2.2 volt

The LEd's have different illumination strengths and view angles.
They are also available as low current LED's and as High Brite led's.
SMD (Surface Mount Device) led's are even smaller then 3 mm, but bit harder to solder the wires.

To connect a LED to a 12V source a resistor is required.
For 12V:
12V - 2V(appr. voltage across LED) = 10V to be dropped across resistor.

For a LED current of 20mA:
10V/0.02 = ~500 Ohms.

500 Ohm is not a standard E12 value, but we can use 470 Ohm resistors.

By connecting the LED's in series we can use smaller resistor values as the voltage across the LED is added up, so less has to be dissipated by the resistor.

Will try to find some blue ones at Farnell/RS and test it.
Didn't see any blue ones with integrated resistors though.
Other colors are also available with integrated resistors within the LED. So you can't see the difference.

Great, LMK if they will fit as soon as you get them.

Yes, would not have been my first choice either, but they were the brightest LED's that are available in the mini's. The price difference between the red and blue was too much for me and the blue were not that bright anyway (but probably brighter than the stock ones). $5 for blue (each) and $0.30 (each) for the bright red ones.

The LED's I used are the exact same size as the stock LED's. There is enough space between the rocker and the base to use a normal size LED though. Tried that and there's enough clearance.

Resistors (should have clarified - STOCK resistors) are 1k ohm (5%). You can get the mini's (like 1/4w?) and they will work fine, not talking a lot of current here.