Testing some Instrument LED

[Uwon]

Engelbert, nice web site. I'm sold-order going in today.
Like many of us, I am looking to also install LEDs for my parking/brake/turn signals-there is so much crap/horror stories out there and I have limited LED understanding, so a specific offering from someone such as yourself would be welcome (and a nice addition to your web site).
Cheers,
Johan

[spuggy]

Originally Posted by rothaus

These (and any LED's) cannot be dimmed as you describe with the dimmer in the light switch. I have not played around with a separate dimmer yet. However, if you like to keep the gauges dark or just very low on light, I would not install these LED's.

I too like to turn my instrument lights down; on country roads, I prefer to turn them down until they resemble watch dials

Etarga's LEDs are dimmable on the factory rheostat. They cut out completely about half-way through the range, but they do get dimmer (although not as dim as I'd like). In the city, I run them a little brighter - the big win is the even illumination...

I did research LED dimmers - e.g. to get 0-100% control - but it's not a high priority for me.

[PGG911]

I installed the Vintage White + 1 Green, 1 Blue set today in my 84 Carrera today. I could not be more pleased with the results. They look great.

[BrakeL8]

Picked my car up from the shop and they'd put in the vintage white/green/blue set.

While they didn't put in the green nor blue (WTF?!) the vintage white are fantastic.

No super duper white like my Mercedes however fantastic illumination. Aesthetically I'd describe it as changing the batteries out in the old lights. Same color - just super easy to read at night. Thanks for making these!

[ShakinJoe]

Nice work

[drleah]

Thanks for making these! I finally installed mine and love them!


Success is not final, failure is not fatal: it is the courage to continue that counts.

Winston Churchill

[911T70]

I received my LED bulbs last week and was very impressed with the quality. I was curious about the circuitry so I reverse-engineered them and tested them, measuring the current flow. Having designed and built numerous LED systems used in aerospace and photochemistry research for over 10 years, I was worried about power dissipation and over-heating. These bulbs are well designed, well within the specs of the components at 12 V. I'm not sure at what voltage my car's charging system regulates, but even at 13,8 V the limits aren't exceeded. I was planning on making my own LED bulbs but at this price, it's really not worth it. I like how they throw light to the sides - nice design! These are a great value and I can't wait to install them in my 911.

Here are two photos. The first one shows the total current flow (39 mA). A 2W bulb draws 167 mA and produces much less light!
The second photo shows the bulb as it's turning on, at low voltage. An image at 12 V would totally saturate the camera.

Thanks for these bulbs, Englebert!

[porwolf]

Good setup 911T70; As for dimming the lights what do you think about feeding all instrument lights with common pulse width modulated driving circuit that could be using the Porsche rheostat as control element?

[NYNick]

I too am interested in an easy fix for my turn signals. I can hardly see them!

[911T70]

Originally Posted by porwolf

Good setup 911T70; As for dimming the lights what do you think about feeding all instrument lights with common pulse width modulated driving circuit that could be using the Porsche rheostat as control element?

Using PWM is one way of doing it but it would require an additional circuit. I don't have any of my 911 manuals with me and a quick search on the internet came up with nothing useful - does anyone know what the dimmer is? A variable resistor? What value range?

The side LEDs start to come on at 5 V and the top ones at 7.5 V. I haven't installed my bulbs yet - does the dimmer not dim the bulbs? I'm sure there is an easy solution.

[porwolf]

I came across a rennlist thread dealing with an add-on PWM circuit that a member there built and is selling for 928 cars. Looks very good and it uses the original Porsche rheostat to control the dimming. That should work also for 911's. I cannot think of any reason why the 911 instrument lighting is much different:

PWM dimmer for instrument backlighting after upgrading to LEDs - Rennlist Discussion Forums

And here is where you can order the dimmer as a complete unit or parts kit for do your own:

http://www.protizmo.com/Product-Info/AILD-1/

[SpyderMike]

Go search "PWM controller" on Amazon and there are several for ~$10. I used one version on my niece's power wheels electric cars and they have really worked well.

[porwolf]

Originally Posted by SpyderMike

Go search "PWM controller" on Amazon and there are several for ~$10. I used one version on my niece's power wheels electric cars and they have really worked well.

But the trick is to be able to control The PWM controllers with the existing Porsche Rheostat. Not a simple feature because the total resistance is only a couple of ohms. The other challenge is to avoid any HF switching noise that can disturb the audio system. I read through the rennlist thread and the guy who described and developed his system there seemed to be on top of all the issues.

[Neilnaz]

PM sent to Rothaus.

Regards, Neil

['76 911S 3.0]

Just ordered a set off the site! Can't wait!

[911T70]

Originally Posted by porwolf

But the trick is to be able to control The PWM controllers with the existing Porsche Rheostat. Not a simple feature because the total resistance is only a couple of ohms. The other challenge is to avoid any HF switching noise that can disturb the audio system. I read through the rennlist thread and the guy who described and developed his system there seemed to be on top of all the issues.

I had a quick look at the Rennlist thread (didn't read all 15 pages) and that guy did good work. His solution seems a bit complicated but maybe I'm not aware of all the issues yet. I now know that a rheostat is used and that its resistance varies from 0 to 6 ohms (in a 928 - don't know what it is in an early 911). I only have access to my car on the weekends - I'll make measurements next Saturday.

Does anyone know how Englebert's LEDs behave when the dimmer is used? Wonder what voltage range is swept?

[SpyderMike]

Originally Posted by porwolf

But the trick is to be able to control The PWM controllers with the existing Porsche Rheostat. Not a simple feature because the total resistance is only a couple of ohms. The other challenge is to avoid any HF switching noise that can disturb the audio system. I read through the rennlist thread and the guy who described and developed his system there seemed to be on top of all the issues.

Understood. In my case I am stripping my car of all unnecessarily systems (audio, interior lighting, AC, power door locks, cruise control, etc.) and going bare bones. I will install LED lighting in the gauges and then add a pwm controller somewhere under the dash. In my mind it is a set and forget issue. I don't need to tweak it for different driving conditions.

[Pierre911SC]

What do you guys used for turn signal (green) ?

[rothaus]

I don't have the LED's for the turning signal indicator. These bulbs are different, and I have not done any testing myself.

However, there is another thread on that, together with the LED's in the turning signal lights.

Here are some links.

LED conversion -- highs, lows, and relay swapping

LED conversion


Cheers
Engelbert

[rothaus]

Originally Posted by 911T70

I had a quick look at the Rennlist thread (didn't read all 15 pages) and that guy did good work. His solution seems a bit complicated but maybe I'm not aware of all the issues yet. I now know that a rheostat is used and that its resistance varies from 0 to 6 ohms (in a 928 - don't know what it is in an early 911). I only have access to my car on the weekends - I'll make measurements next Saturday.

Does anyone know how Englebert's LEDs behave when the dimmer is used? Wonder what voltage range is swept?

I have not measured the voltage, however, I noticed that between the 71, the 82 SC, and the 87 Carrera the bulbs dim different. I think that these light switches getting old and therefore not consistent. They work may on the standard bulb OK, but not the same when the LED's are installed.

Looking forward to the option with the PMW. That would be a nice addition to the LED's, if complete dimming is needed.

Here is a video from the installed LED's in a 914 dash. It has a good range of dimming.



Cheers
Engelbert