Do I need a External uBec

[BrianG]

Thanks BitHed! I did some searching around and found there were a lot of explanations and diagrams, just nothing in one place. So, I came up with a single place to go to.

jhautz: Wow, that looks like it got quite hot indeed! Although, the regulator will get just as hot on a bench as it does running, probably more so since there is no airflow. Even at a 1A load, the regulator will have to dissipate 16w @5s. That's a lot. Now that you know where the IC is, you couldcut away that part of the plastic and mount a heatsink on it. :)

I'm wondering why these would actually burn up though. Most linear regulator ICs have a thermal and current overload sensor and simply shut down. Maybe it just happens too quickly for these circuits to respond.

Basically, if you even think you might need a UBEC, get one. At worst, it will be a waste of a few bucks. At best, it'll run much more efficiently.

I don't know if anyone noticed on my BEC calculator page, but a UBEC actually increases runtime over the built-in one. Since a UBEC is really a powerIn=powerOut device, the draw from the main batteries is lower than the BEC load current, especially at higher cell counts. While a built-in BEC pulls the same current from the main batteries as BEC load current. Just thought I'd point that out. :)