Citroen XM Forum

I can see now:
If you remove the bulbs, you can't push the new wires into place any more. You'd need to lift the connector flaps to do that and there is no room for that.

Back to the drawing board with the BX switch. The solution is not to remove the wires but to cut out the old bulb, then to use the remaining wires and solder the new parts is situ. A bit more complicated but the only way.

That's right, so I did remove the old bulbs, ...but then also managed to wedge the led legs in that area and used the left over wires to make contact with the led legs. I know it was fiddly.

Isn't there a conductive glue so you can glue the LEDs in place? Might be making that up!

This switch is definitely the worst to convert.

I can get my BX switch on Tuesday and I'll see then.

Even with soldering in situ (relatively hot iron but very quick soldering) this is one place where the through hole LED would be easier to use than the SMD solution. Could you add a link to your LED source? The web is full of LEDs but who knows whether the brightness figures are reliable or not... I'd prefer the same brightness of 350-400 mcd and green color that I have with the SMD LEDs now. If you have the brightness all right, I find that green is better than white, it gives a nicer, more vivid green color. The original switches with white LEDs inside are visibly yellowish-greenish compared to my new ones (see the first dark picture above, there is a marked colour difference between the seat switches and the centre console ones).

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Hi Gabor,

This is all looking rather good!
If you need to know the exact spec of almost any LED, look at Rapid Electronics UK site, or Conrad Electronics UK site. With almost every product offered, there's a manufacturer's data sheet available (hit the product, then Details/Downloads, and then the PDF for the data sheet).
Both companies despatch anywhere. Found them good.

No need to do that with Conrad, their Budapest store is, well, in Budapest. [emoji1] I normally only buy stuff from them that's exclusive to them, their prices are usually a bit exorbitant. I had a package delivered just a week ago, actually, with the first batch of LEDs and resistors I played with (I needed something else from them and added this to the delivery). Then I decided I needed more light and a wider selection of resistors to play with and simply went to another supplier en route while doing some errands. Guess what, same SMD resistors for 1/9th of the Conrad price... 5 resistors or 10 for a penny, I can't even calculate with such low a figure... [emoji1]

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But ay, there's the rub:

http://uk.farnell.com/kingbright/l-934g ... dp/2217964" onclick="window.open(this.href);return false;

https://www.lc-led.com/View/itemNumber/583" onclick="window.open(this.href);return false;

See that mcd at the first? Rubbish. And at the second? That's a theatre spotlight for sure. I tried Rapid's site, too, but nothing in the middle range so far.

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Quite right....it's all in the figures! That first LED must be one of the dimmest I've seen listed.

On the resistors front, several years ago I ordered a "complete range" pack of small resistors, which included 10 of each value (c 150 values) from 1R to 10M. Saves lots of scratching around and one-off shopping trips. Think it was from Maplin, and a tiny price. They did similar range-packs of capacitors of various types. (Had to buy a plastic drawer unit to put them in, though!)

Conventional resistors come in various physical sizes.
The larger the size the more power they can take so size is described in Watts.
For use with small LED's one eighth Watt is the smallest conventional size generally available.
An eighth Watt resistor is actually slightly smaller than the equivalent surface mount resistor.

I have some samples made up in dash bulb holders.
These white LED's are 6mm square and 2.5mm thick.
Will see if I can find the spec sheet for the LED's and colour range.

Now found the spec sheet for these LED's (type 5050).
Output from White ones can be varied between 5000 &6000mcd.
Output from Green ones can be varied between 2500 & 5000mcd.

If I was making up switch lights I might well try using 3528 type LED's.
These have a single LED on the 3.5mm by 2.8mm chip which is also thinner at 1.5mm thick.
That compares with the 3 LED's on the 5050 chip so the light output is a lot less.

John

Yep, I know the 5050 ones. Actually, my next plan would be to try a few T5 LEDs strictly in those places around the centre console (ashtray, ashtray and radio flap, maybe the suspension switch) where light distribution is not as critical as in dashboard and warning lights.

For conventional resistors, I don't need any shop, I still have shedloads of them from my radio amateur past but SMD is different.

1206 is 0.25 W and the actual power with the LEDs I used was 0.2 to 0.22 W. Conventional and conservative calculation says 60% of rated power, that's one of the reasons why I switched to parallel resistors that can handle 0.5 W now. And the fact that it's much easier to make the required resistance, you simply don't have standard resistance values close enough to what you need here.

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Basically, as I said, I'm very much satisfied with the switches I converted. Twice 360 mcd green is just fine for me. The only problem is with they one-touch switch because you do need a single 3 mm or smaller, 12 V LED there with no external resistor. Nothing else will fit. I tried to rig one with the 1206 LED stacked over the resistor and I simply don't trust it never to obstruct the switch operation. There isn't half a millimeter to spare there, it has to fit in the size of the original bulb.

That's why I'm looking for an appropriate LED, preferably green because I was grown to like that better, but will settle on white if necessary. Around 500 mcd seems to be enough because I don't want it to be too bright and, what's even more important, I don't want it to be significantly different from the neighbour switch already converted. But this is strictly for that single switch, nothing else.

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