electrical question

eurotrotter

hi guys
hope yer well
i have a scooter and want to fit extra lights out the front, there high power LEDS
i have a 12v dc supply, as you'd expect, but the high power LEDS can only take 4v's, i want to fit 2, how am i gonna do this?!
here is the link to the LEDs:
http://www.maplin.co.uk/Module.aspx?ModuleNo=35735&criteria=high%20power%20led%2012v&doy=23m11


replies greatly appreciated
ed

PDelux

Alot of this can be found on the web. Just googled and found this good example
http://www.theledlight.com/ledcircuits.html

If you need to bring down the 12V to some smaller voltage look up Voltage Regulators in Maplin. Make sure it accepts a 12V input though.

eurotrotter

i wanna just be abke to throw a resistor onto each LED to get it down to the 4v
thanks

greglo23

fit 3 and wire them in series. eg same as the first diagram in the LED circuitry page !!

Ghost Train

eurotrotter wrote:

hi guys
hope yer well
i have a scooter and want to fit extra lights out the front, there high power LEDS
i have a 12v dc supply, as you'd expect, but the high power LEDS can only take 4v's, i want to fit 2, how am i gonna do this?!
here is the link to the LEDs:
http://www.maplin.co.uk/Module.aspx?ModuleNo=35735&criteria=high%20power%20led%2012v&doy=23m11


replies greatly appreciated
ed

I think the spec sheet says the forward current for them is 30mA, so thats the current for the resistor

If you want 4v across the led, say you'll have 14v from the battery when it's charging, so there'll be 10v (14-4) across the resistor

voltage=current*resistance
so the resistance of the resistor will be voltage 10v divided by current 30mA

so the resistors should have a value of at least 330ohms, something around 400ohms or 500ohms would probably be fine, wired like the last diagram on the above page

The Doktor

here ya go...

http://home.cogeco.ca/~rpaisley4/LEDcalc.html

Do u want the leds on ur scoot too for the look, or to give u more light?

eurotrotter

so drivers can see me, but for teh look as well!
u drivin one?

The Doktor wrote:

here ya go...

http://home.cogeco.ca/~rpaisley4/LEDcalc.html

Do u want the leds on ur scoot too for the look, or to give u more light?

Tormentd

IMHO the best thing to use is a couple of spot lights. you can get some nice small ones and make it a real tidy job. Battery drain could be an issue, but if you use them only at night it should be okay. leds are too small to be seen by drivers. I had scooters and bikes, I know what they are like!! Although you can get LED clusters that should work directly off a 12v supply.

mathias

Here ya go ,

I think this would be more along the lines of what you want , and no need for any resistors or anything , cheap too !!

http://www.minimoddesigns.co.uk/Shop/section.php/20/0