Ohms law, electronics math question

[Mathster]

What is the voltage rating on the LEDs?
What is your source voltage?

Typically, an LED has a 2 to 3 volt drop. You can get LEDs with different voltage ratings, they are usually either clusters or have a resistor in series with them.

The easiest method is to buy a potentiometer and dial in the brightness you desire.
Mathematically, measure the resistance on the LED (forward).
I=V/R (use this to find the theoretical current or your target current. R that you measured on your LED, V at its rated voltage)
RR=V/I - RL where RR is your resistor, V is your actual voltage, I is calculated above, and RL is the resistance of you LED.

[F1]

Try this page for your formula's, Caz......

http://www.angelfire.com/pa/baconbacon/page2.html

[cauzomb]

What is the voltage rating on the LEDs?
What is your source voltage?

Typically, an LED has a 2 to 3 volt drop. You can get LEDs with different voltage ratings, they are usually either clusters or have a resistor in series with them.

The easiest method is to buy a potentiometer and dial in the brightness you desire.
Mathematically, measure the resistance on the LED (forward).
I=V/R (use this to find the theoretical current or your target current. R that you measured on your LED, V at its rated voltage)
RR=V/I - RL where RR is your resistor, V is your actual voltage, I is calculated above, and RL is the resistance of you LED.

My supply voltage is 2.545v full charge and 2.47 low charge, not to worried about the brightness, but I do have a basic stamp pwm to fool around with.. I can't reprogram it "haven't done that b4" so I don't really know.. But I can hook it up as a pulser to be more noticable.

Supply voltage measured across the LED = .31, or a total vdrop of 2.235v

The led's are Vf 3.2-3.6, but I'm ignoring this for my application; I'm just worried about the current because that can kill the LED fast and the circuit "wireless 360 controller" runs off 2.5v at a higher current rating than the typical watch battery LED circuit.. Strange thing is, with the controller on, the draw on the controller battery seams to either drop the voltage a little too low for my LED's or there's a transistor inside the battery that switches it to another leg of the contact.

Oh a new twist to an old trick, sticking axial caps in the wall plug is fun!/noisy and dangerous... the new twist on this is the LED.. they go off like firecrackers and send out shards of polycarbonate or whatever the lense is cast out of. But you know... You always gotta see what stuff does when you plug it into home AC

:P blown up capacitors, LED's, potatoes, uhm oh one time I hooked a 9v battery into the wall outlet... NASTY!!!! red hot melted stuff.... What little I knew when I was a kid, didn't realise I could have burn the house down... now all these things get plugged into an isolated psu at relatively low volts, but higher current :O