put a light bar on my slash

[BrianG]

Regular LEDs typically need ~25mA to achieve full brightness. This is accomplished via a current-limiting resistor. Failure to use something to limit the current will result in them burning up, short life span, etc. I suspect the only reason they aren't burning up on you the way they are set up is because you have two in series, and each typically has a Vf of ~3.5v. Well, the BEC's 5.5v is not enough to fully turn them on, so that limits the current.

Here is a page I recently created for just this sort of thing. Be sure to read the help thingies because there is a lot of info there: http://scriptasylum.com/rc_speed/_led.html

[t-maxxracer32]

Originally Posted by Fast5sRevo88

T-Maxx; this is off topic, but can you tell me the dimensions of the battery tray on the slash?

roughly 1 11/12 inch by 6.5 inch

Originally Posted by BrianG

Regular LEDs typically need ~25mA to achieve full brightness. This is accomplished via a current-limiting resistor. Failure to use something to limit the current will result in them burning up, short life span, etc. I suspect the only reason they aren't burning up on you the way they are set up is because you have two in series, and each typically has a Vf of ~3.5v. Well, the BEC's 5.5v is not enough to fully turn them on, so that limits the current.

Here is a page I recently created for just this sort of thing. Be sure to read the help thingies because there is a lot of info there: http://scriptasylum.com/rc_speed/_led.html

thanks brian. Ill look more into that.

are you saying that i should put a resistor on it or with the 5.5 volts is it okay?

and how can i know or calculate if each is getting 25 ma?

thanks!