Brigther dash?

Post by **Multiphonikks** » Sun Nov 13, 2005 9:41 pm

Has anyone managed to use LED lights in place of the standard 12v 2.2w bulbs in the speedo to light the speedo up?

The ones in Carrie aren't quite as bright as Hebe's so I've been cooking up plans to get them upgraded

Nikki

P.S. I officially hate electrics.

Post by **Cam** » Sun Nov 13, 2005 9:47 pm

I've seen it done in Minis (similar speedo) and you can get different colours and intensites. I have to say though for my tastes the light looked a bit 'clinical'. Too white - a bit like BMW headlamps. Not really in-fitting with an old car.

Post by **Multiphonikks** » Sun Nov 13, 2005 9:49 pm

Hmmm.

Cam, I'm hoping to recreate the right colour and not too intense though... Any ideas to suitable LEDS to use? Carrie's Speedo is based on a Mini one

Post by **Cam** » Sun Nov 13, 2005 9:53 pm

Trouble is though re-creating the 'right' colour is very difficult with LEDs. Best bet is to try to find out why THIS speedo is dark and fix it with the appropriate bulbs. Sometimes the holders fall out from behind or a bulb goes. Take it out and have a gander...

Post by **Multiphonikks** » Sun Nov 13, 2005 9:55 pm

Aye... I'll do that tomorrow. I found the ignition warning light had taken a little trip somewhere behind the steering column!

Post by **bigginger** » Sun Nov 13, 2005 10:34 pm

You just can't trust the people who build them, can you. A real Friday afternoon car...

Post by **Cam** » Mon Nov 14, 2005 12:07 am

Post by **woo** » Mon Nov 14, 2005 1:16 pm

Nikki,

Contact RS Components. They sell 24 volt dc White LED's. They are cheap enough to experiment with and, being 24 volt, might not be too bright.

Maplin Electonics only sell a 3mm 12 volt LED's in Red Green and Yellow.

Robin

Post by **Cam** » Mon Nov 14, 2005 1:24 pm

woo, the trouble with those LEDs (and LEDs in general) is that the light is very white and not slightly yellow like the old bulbs, so it looks quite clinical in a Minor dash (well the Mini ones I saw do anyway).

Post by **paulk** » Mon Nov 14, 2005 1:41 pm

Cam et Al

On an old radio I had the LED's had little (for want of a better word) coloured condoms on them. These made the bright LED much subtler.

I'd imagine the material is special cos they get quite hot, but a possibility none the less.

Post by **Willie** » Mon Nov 14, 2005 5:25 pm

Almost every Minor I have come across has had panel lamps which were so
old that they had blackened glass which greatly reduced the available light.
If you are lucky you just need new bulbs.

Post by **MikeNash** » Wed Nov 16, 2005 7:06 am

Has anyone fitted LEDs? I'm interested 'cos I'm up to three extra instruments with another three to fit and each has its 2.2 watt bulb to power that my dynamo could do without. (And before you start on alternators, I like my dynamo amd my dynamo likes me. Loyalty among old friends is a virtue.) I've thought of connecting the bulbs more in series but the instruments' earthing through their cases makes that difficult.
I'm not too good at electronics, so any pointers will help. Has Mr Woo tried it with his RS Componet stuff? MikeN.

Post by **ColinP** » Wed Nov 16, 2005 8:47 am

Just a couple of thoughts:...
1)

Contact RS Components. They sell 24 volt dc White LED's. They are cheap enough to experiment with and, being 24 volt, might not be too bright

LED's aren't like filament bulbs - if you turn down the voltage they will just not work - they don't change colour. If I remember corectly, the LED works from about 3v, so there's a zener diode across the input/output to give a constant voltage to the LED (and a series resistor to limit the current through it). The only way is to change the colour of the led by either a coloured sleeve, or the chemistry of the device.

2) Is it possible (cheap!) to use a fibre optic?

3) Nikki, can you fit a small rheostat into the dash lighting circuit? Lots of more recent cars have that, and by altering the voltage it should change the colour of illumination..

Luck,

Colin

Post by **lowedb** » Wed Nov 16, 2005 1:19 pm

A few points about LEDS.
First there are two ways of making white ones. You can use three (or four) LED chips on one package, with red / green / blue. You can then in theory change the colour by varying the intensity of each colour just like on a telly. Trouble is these LEDs are not cheap and require a bit of work to drive.
You can change the intensity of LEDs. There is a minimum voltage below which they won't work, but they are basically current controlled evices. The more current, the brighter up until you drive them so hard they burn out. A better and more controllable way is to use PWM (pulse width modulation) where you turn the current on / off very quickly and vary the on to off ratio.
Finally a note on why white LEDs seem 'very' white. The majority of white only LEDs are in fact not white at all. They are Blue LEDs with a flourescent layer in front. The blue light shining on this causes the coating to glow white, but a bit of the blue always shows through giving that 'hi tech' bright white look. These LEDs are much cheaper than the RGB ones, but the colour can only be changed with a filter as someone else suggested.

Post by **ColinP** » Wed Nov 16, 2005 1:23 pm

Thanks - I knew I wasn't quite up to date on solidstates, but WOW ;-)

How about one of those old "Galaxy lamps" for fibre optic lighting? - Ever changing colours for the panel lights ( is this getting silly?)

Colin

Post by **Multiphonikks** » Wed Nov 16, 2005 1:24 pm

I'm finding it rather fun

After all, my car is erm.. *cough*

Post by **woo** » Wed Nov 16, 2005 4:08 pm

I have used 12 volt LEDs. I have a small plate under my dashboard with switches for Fog Lamps, Rear Screen Heater and Variable Speed Wipers. Each switch has a coloured 12 volt LED between the output side of the switch and the earth to show me when it is switched on. I have also used 'White' LEDs to illuminate this plate which are connected to the Side Light circuit. For this I experimented with different size resistors until I got the brightness I wanted. But I would still have thought that 24 volt LEDs run at 12 volt would be worth experimenting with.