Looking for information on driver boards

[Charon]

I seem to be unable to find a thread or information on everything that driver boards are about.

Different types, setups they are using in, how to use them, terminology ... etc.

Basically I am interested in adding drivers to U-Bin P4 LED's to operate them with constant output. So trying to educate myself on them to figure out what I need and so I can do more in the future.

 

[TorchBoy]

:welcome:

Have you stumbled across the Welcome Mat? It has information about what all sorts of words mean. http://www.candlepowerforums.com/vb/showthread.php?t=172991

For details on specific drivers, you could do worse than to start with http://www.candlepowerforums.com/vb/showthread.php?t=188227

 

[Charon]

Thanks, I've only been here a short time and have plunged much too deep into lights then any sane person would.....

Reading parts out of that helped some. Now perhaps if I explain what I am thinking of doing.

I want to replace the interior light of my car with a much brighter solution. I figure this could be had with 4 Luxeon III led's. I picked this led as I believe it has the best flood. Now each running 3.7V and 700mA. Vehicle voltage should be from 12.6V to 14.4(possibly a little higher) I am looking at running the LED's directly in series 4 * 3.7V = 14.8.
The LED's on dealextreme list a driving voltage of 3.0~3.27V which means 13.08 max voltage recommended ?

Im trying to figure out if I need a driver(s) or I can run this directly if I put a few in series. Or will I start to see magic smoke ? Im really in the thinking phase of this project as I am quite new to electronics design. Am I on the right track with any of this or am I a sandwich short of a flashlight(picnic) ?

 

[TorchBoy]

I dare say a couple of Crees will work much better than four Lux IIIs. They certainly have the efficiency to do so, and the beam angle of the Cree is more than adequate. Crees are also cheaper. However, if you absolutely want a wide flood - unnecessary in a car, I believe - you could try a SSC.

There are problems with using four LEDs in that situation. One is that the total Vf of the four needs to be high enough to cope with the peak charging voltage. If not, it's lights out, literally.

The other main problem is the variability of the voltage, as you indicated. With the car turned off it might be as low as 12.0 V, and with the car turned on as high as 14.5 V or so, just a turn of the key later. That's 3.0 to 3.625 volts per LED, which would work out at 50 mA to 1100 mA for Lux III figures I've seen - a huge variation in brightness, and IMO not desireable even if you wanted to run your Lux IIIs at 1100 mA.

Am I on the right track with any of this or am I a sandwich short of a flashlight(picnic) ?

I'm not sure if you know that's an obscure and clever pun. (A sandwich being a type of driver board.) :thumbsup:

How about you try this drop-in? (Or one of its brighter and more expensive siblings.) It comes with a driver that will work fine with the variation in voltage, and you will be able to expand it simply by adding an extra LED or two when you want to upgrade. With the minimum voltage available the driver can cope with up to three LEDs in series. It should be a good first project, and will give you a decent sense of modifying. Heatsink the LED well and save the reflector for a later project.

You might find this thread interesting. Note that the Kennan driver is not actually available at present, even though KD says it's in stock. However the driver in the drop-in I mentioned is almost identical (which is why I suggested it).

 

[Charon]

Thanks for the direction. Looked through that other thread and your links. Looks like a Subaru forester in your pictures?

I am thinking of trying the following
http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=2982
With one or two Crees in series and more if I want to upgrade for the cabin. And then another with 4 for the boot.

I have 4 Seoul U bin P4 I could use these as well, but Im afraid they may be too bright for the application in the cabin.

The drop in you recommend looks rather large(in height) I want to try to fit something under the stock dome plastic. I have enough gear to build an aluminum heatsink for the LEDs for mounting.

Thanks for the help

p.s. I did realize the pun when typing it

 

[TorchBoy]

Looks like a Subaru forester in your pictures

Hey, you're good! It is.

The drop in you recommend looks rather large(in height) I want to try to fit something under the stock dome plastic.

You wouldn't use the reflector, just the driver and LED from it, which are around 14-16 mm diameter from memory, and a few mm thick. I suggested it because even though KD says they have the Kennan is stock, it isn't, and the driver from that drop-in does the same job using the same regulator chip. But let me know if you order any Kennans and they actually send them.

You can use the Seouls no trouble, just add one or two in series with the Cree from the drop-in. That boot of yours will certainly be bright with four LEDs.

 

[Bones]

...
Looks like a Subaru forester in your pictures?
...

Hey, you're good! It is.
...

And here I thought you must have used the optional vehicle adapter to power up your latest version of the MH-C9000 ...

Hi Bill, you've inspired me to post before and after shots of the car cabin light I fitted yesterday, fashioned from a couple of Cree P4s and a Kennan from KD. It runs at about 6W, a bit less than the original bulb.

NOT a Luxeon dome light. :tinfoil: (Nah, it's not really that bright, but it might be a tad too much for map reading - night vision it's not.)

Do you think it would have been more or less bright had you actually done so ...

 

[TorchBoy]

Ha ha. The car doesn't seem too bad, so maybe I've got used to it now, or maybe I didn't use enough heatsinking and the LEDs have faded. I was doing some beam comparisons with various optics and reflectors earlier today and the star on the Cree certainly got hot quickly at one amp. Make sure you heat sink it well, Charon, or reduce the current put out by the regulator board.

Anyway Bones, I think you saw the beamshots I made of my charger. (Only on CPF!) I can't remember what thread that was in.

 

[Charon]

Hey, you're good! It is.

I suggested it because even though KD says they have the Kennan is stock, it isn't, and the driver from that drop-in does the same job using the same regulator chip. But let me know if you order any Kennans and they actually send them.

I received four of them in the mail and have five more on order. Just letting you know that they did send them. (well at least four of them)