Cheap BEC mod

[BrianG]

Now that most of my ESCs have switching regulators built-in, I have several external BECs not doing anything. I modded one in a recent project, but thought others might have something similar.

I have a few $5 Chinese BECs I got from eBay a while back and they are supposedly switchable from 5v to 6v via a jumper. With the jumper in place, I do get pretty much exactly 5v, but without the jumper, I get something around 5.5v. Well, I want 6v dammit!

The untouched BEC. Note the voltage, which is on the 6v setting:



With the shrinkwrap off and the capacitor bent out of the way, you can see the components I will remove (circled in red):



With those parts removed:



A little trial and error later, I found a 2.2k ohm resistor gets me a little over 6v. Here is the resistor in place. I just reused the jumper pin holes:



The end result. All I need to do now is re-heatshrink it and I'm ready to go!



I also like to add a little heatsink to the back of the PCB to help cooling a little. These are efficient, but they do still dissipate heat. If you do add a heatsink, make sure it's only on the ground trace and do not bridge any other traces.

This is just one specific type of BEC, but most based on this main IC will be very similar. These BECs are not technically designed to be adjustable. So, don't try to get voltages that are too high because the inductor used is sized specifically for a certain voltage. According to the datasheet, they are good for a range, but I would change the voltage no more than ~20% max.