LED bulbs

[marcus]

Good idea. I reckon that modifcations are best when they are reversible to original condition. Show Cars are best in original condition, but those that are driven regularly can be made far more pleasant and dependable with a few modern conveniences!

[AndrewG]

On the subject of running hot, some LED headlamp conversions now have a fan so that the heat sink on the power supply can be minimised.

But I think once we're talking LED power supplies, we are talking of the devil's work - indeed I put my chair is on a rubber mat just to look at photos like the one below.

[AndyL]

I went for passive heatsinks on mine, however obviously much lower wattage than the commercial units, plus I have quite a lot of room in the Isetta teardrop headlight housings for the larger area

Many installations can be quite tight, so an active heatsink is sometimes desirable.

Power supplies are relatively straightforward for LED's. If you have to drop a lot of voltage at high current then switch mode supplies are best, and cheap on ebay. For lower current linear regulators are inexpensive and rugged. Most of the LED units have current limiting built into them, so just plug and play.

The efi will all be pretty much bolt on, so the car can be put back to standard easily and quickly. The areas where a bit of modification is necessary, is increased wiring for the sensors, plus a bung has to be welded into the exhaust manifold for the lambda sensor. The sensor wiring can be run as an independent loom.

 I like to drive cars once they're roadworthy, so sitting round in a field polishing the underside of a floor pan does not throw my switch.

[plas man]

What you can't do is use them in standard indicator circuits with a bi metallic electro mechanical flasher. This is owing to low current the LED's draw from the supply not permitting the unit to work as it should. So you either need to use parallel resistors, which nixes the advantage of the low current draw, or fit an electronic flasher.

thanks for the vast number reply's guys , as for the flasher unit the one I fitted to my Bond in the 1960's is of mechanical operation ( clock work in other words ) so should have no problem with bi=metal strip warm up . instead there is a set of contact points like the Lucas type .

That aside I have forked out a couple of quid and going to do some experimenting - on the bench , whilst looking thru' the box's  for suitable ''scrap'' ( older ones that's still nice and shiny ) light's to play with .

[AndyL]

If it's relay based then should work fine.

[Big Al]

I know you have to make a bit of heat to make light, and vice versa. Ro much heat starts to sound inefficient. So when we are  talking about to much heat I assume that once you reach the sort of light needed as a headlight the heat produced is taking out the unit creating the light, unless its cooled.
I like the answer, add a motor, using extra power. It starts to not be a simple solution to a problem. Still its all interesting stuff and research continues. Can only be good.

[AndyL]

The best power LED's tend to be about 60% efficient. So for say a 6 watt LED, 3.6 watts is going to be produced in heat. This is much better efficiency than a few years ago, and it's improving gradually year on year. The cooler you can keep your LED the better the efficiency.

Now bear in mind most power LED dies are very small components, e.g 3-5mm across, then you require a fairly good heatsink to keep the component within its rated temperature spec.

The most difficult aspect is ensuring the heat spreads out adequately from such a small area to a much larger area.

[DaveMiller]

Back to the subject of home-made conversions:  do take the required colour into account.

The old-fashioned incandescent bulbs produced light in a broad range of colours, adding to "white".  This meant that there would be plenty of light left, when filtered by a red rear lamp lens, or an amber indicator lens.

A "white" LED, though, produces only a few particular frequencies, usually quite strongly blue.  If there's very little amber or red in there, not much light at all will get through the coloured lens.   For indicators and rear lamps, you need to start with amber and red LEDs.

[marcus]

Very good point Dave!

[plas man]

this topic is getting interesting , but tomorrow I will visit the local motor factor and see if they sell replacement bulb's in led format , will let you know the results , once again thanks for all information given .
the £ shop lights will fit nicely under the pelmet on the model railroad , and there is a 12 volt suppy at hand 

[DaveMiller]

tomorrow I will visit the local motor factor and see if they sell replacement bulb's in led format

I've found that most motor factors, Halfords, etc don't stock them (and I've wondered whether it's because all automotive lights are supposed to carry a European code, or something ...)

They're readily sold at classic car shows, though, and of course on eBay.

[AndrewG]

I've found that most motor factors, Halfords, etc don't stock them....

Well, it looks like they don't stock them.  If you gave yourself six good sprays from a can of aerosol acne,  lowered your trousers sufficiently to display your chosen brand of underwear and then asked to see the stock 'under the counter', you'd have them at once.

[DaveMiller]

I've found that most motor factors, Halfords, etc don't stock them....

Well, it looks like they don't stock them.  If you gave yourself six good sprays from a can of aerosol acne,  lowered your trousers sufficiently to display your chosen brand of underwear and then asked to see the stock 'under the counter', you'd have them at once.

Good heavens.  You mean I should go in without my monocle?

[AndyL]

Most of the customers I see at the local Halfrauds are middle aged men going their to get batteries, wipers or headlamp bulbs replaced. You see some little lass struggling out with a battery as big as herself, with some burly looking bloke standing by the side of his motor with his arms folded. Comical.

[plas man]

well no luck at the local motor factors , the high street shops selling numerous types of bulb , now maybe we should stock up on the present day bulb for our family car use just in case  , as the long livery of LED's  might make the humble bulb unobtainable ?