sugest a driver for 3 x cree bike light

[aljsk8]

hi ive tried a little searching but i cant find what im after

i want to power 3 x cree or seoul to around 3/4 of the total potential
so mabee 750ma?

i need a driver that will do this from a bunch of aa cells (say 8) or a pack of 6 sub C cells

what driver do i need - as in a link to where i can get one eather in the uk off ebay or online

im on a tight budget so only the cheepest simplest drivers (unless theres one with modes that ar reasonable too

circuit size is not a huge issue but i need something i can put in a container to make it water proof

this is for homemade bike light

thanks

 

[zgurl]

Have a look at AndyTiedye collection of bike related threads here.

For your light, since your battery voltage is lower than the LED voltage, you should use a boost driver. I suggets George's Fatman, which is simple and cheap. You can add an external pot to dim the light. It is not really expensive(22$ I remember) by comparison to more "computerized" drivers with advanced modes.

Keep us posted of your buildings! :wave:

 

[aljsk8]

voltage lower???

8 x 1.2aa = at least 9.6v
6 x 1.2v sub c = at least 7.2v

are you talking lower than 3 in series?

i take it this means they have to be in series to get the correct current

let me know

Alex

 

[ghadlock]

The Shark driver is also good for this application and has an onboard potentiometer for dimming. You can order it here:

http://theledguy.chainreactionweb.com/product_info.php?products_id=721

 

[rivethead147]

this is what i used from a project, cheap, easy to get, stable, and tiny.


http://www.luxeonstar.com/item.php?id=415&link_str=240::241&partno=02009A

 

[zgurl]

voltage lower???

8 x 1.2aa = at least 9.6v
6 x 1.2v sub c = at least 7.2v

are you talking lower than 3 in series?

i take it this means they have to be in series to get the correct current

let me know

Alex

I am not EE but, if your LEDS are in series, you can fix the current, while if they are in parallel, you fix their voltage to be equal. But the problem is that different LED may have different resitance, so that for a fixed voltage, you will get a different current and thus different brightness... So I understand it is better to put them in serie. Maybe someone with higher skills may (or may not) confirm this.

 

[AndyTiedye]

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