22awg wire good for 18v?

[tim.sanderson]

I've bought some LEDs and 22awg wire with the intent of doing a nifty mod to my Heli on R911. What I want to power them off of is 18v, with 6 or so LED's connected in series. It will only be powered up for 5 or 6 seconds every minute or two. Is this gauge OK for use in this situation, or should I have gotten something heavier?

 

[sylvain]

22 AWG gauge is plenty big enough for this application.
You would need a bigger wire size for higher current applications, not for LEDs.

Depending on the LEDs/types, typical current draw need is only 10-30 mA (e.g. 0.01 to 0.03A).
If you wire them in series the current across all will be the same, still 10-30mA.

Do not forget to add a dropping resistor in series, to limit the current flow through them.

An example how to calculate the resistor value and power dissipation for this application:
For LEDs having a forward voltage drop of 2.5V, for 20mA current, say 5 LEDs in series, at 18V supply:

R = V/I
R= (18-(5*2.5))/0.02
R= 5.5/0.02 = 275 ohms.

Power dissipated in the resistor:
P=V*V/R
P= 5.5*5.5/270 = 0.11W

So you would be OK with a 270 ohms, 1/4 or 1/2W resistor.

- Sylvain.

 

[tim.sanderson]

Thanks Sylvain!