I'm amazed at how cheap these are.. Either that or I expected a Porsche type price on them... Anyway, which ones did you use for the doors and overhead lights? 6 or 9 leds? and do you recall what size they are? (Length in mm I mean)... I'm guessing 39 or 42mm. Might be cool to have red interior lights. At $1.95 each you really can't go wrong.

TIA

 

I used the 39mm LED's but they are slightly too short. I would recommend the 42mm, both have 6 LED's inside and the same level of brightness.
If you use 39mm you need to bend the contacts slightly, that's all.
I also changed the light in the glove box and behind the glove box (passenger footwell). They are different, but I can't remember the size. So measure these before you buy...

 

LEDs are unaffected by dimmers....they are either on or off.

 

Shock,

That looks awesome!
Looks like it's time to upgrade the interior lights as well!

 

The best part of this conversion is, that you can detail your car all day without draining the battery!

 

Any feedback on my previous question, Schocki?

Looks like you may still need to replace the bulb that illuminates the HVAC controls - in your pics it appears to not be illuminated.

 

Just ordered a set to replace my interior lights. Red for the footwells (door lights) and light in the hatch, and white for the two overheads.

 

http://news.thomasnet.com/fullstory/468658/rss

Dimmers for LEDs. 5-36VDC source, up to 1A output. Don't know if that's 100% duty cycle or not. Prolly is.

Doc

 

Actually LED's can be dimmed quite effectivley by changing the current through them with a series resistance. These builb replacement LED's are actually an array of LED's and a built in series resistance designed for ~12-14v operation. Changing the voltage across this combined unit does still change its current & brightness...

The problem is that this LED bulb voltage to brightness response is very different to incandescent bulb responses. So the dimming circuit in the car changes the voltage only a small amount for a relatively major change in incandescent luminous output. For the same voltage change the LED luminous output changes more linearly and just a little...

While an alternate voltage based control or a PWM (pulse width modulation) control could give you effective seperate LED dimming, what's really needed here is a circuit that takes the dashboard illumination voltage and dynamically changes the voltage variation to a larger range... very possible but more difficult to do...

If you are just worried that the brightness - while ~fixed is just too high - you can modify that with a fixed additional series resistance. If you get to the right levels you may find that the LED appears to dim more due to the human eyes sensitivity to different brightness levels - which is also non-linear.

Alan

 

I was thinking that you wanted to put the light strip directly under the white plastic. But the way you described it, it shouldn't be a factor.

My HVAC light is OK the first picture was taken with doors open only. If you look through the right side of the steering wheel in picture #2 you see parts of the unit being illuminated.

 

Alan...
By "series resistance"...you mean a pot ??? can a potentiometer be spliced into the 12V supply to the LEDS...to allow "dimmer" capabilties ? As low as the current draw of LED lights is...would a small "fader" type potentiometer wired in series to the 12V supply source be an acceptable means of providing the series resistance ? Or do you need to vary the potential to ground ??

 

Would a variable resistor do the trick? I think I remember hearing something about those in Automotive Technology.


Hope that helps,

 

A variable resistor would be fine - in series - you need to limit the current - typical bright LED's consume ~20mA in bright mode so @ approx 13.5v you would likely already have (13.5v - 1.4v*)/(20mA x5) = ~120ohms in series (internally) for a 5 LED lamp.

You'd want an additional series resistor of say ~5x(+) that value for effective dimming (not down to Zero) So say ~600 ohms for the variable resistor.

You could use a variable resistor of 680ohm/720ohm that would work OK (common values). You would need a 1W resistor at least though and common variable resistors are less than this - you'd likely need a wire wound type and it would be bigger and more expensive than common carbon film types (of maybe .25 watt). If you just wanted to experiment to identify a good fixed brightness level - 1 watt fixed resistors in 10, 50, 100ohm values could be used in series to experiment to find a good fixed value. If you had multiple LED bulbs you'd need different values (lower) and higher power versions...

Alan

NB * LED's drop a forward voltage of approx 1.4v