How to tell if a BEC is linear or switching?


BG has a couple BEC on sale. Switching is obviously better, but how can I tell based of the PCB whether it is switching or not? I assume the ones with more circuit may be switching or perhaps the ones with the large gray module?

These are the BEC I’m looking at:

Probably linear?

Possibly switching?

Advertised as switching.

From my limited knowledge, I assume the second option is the best, but I just want to double check before I buy it, since shipping from china is sooo slow.


Option 2 is your best bet. Switching is indeed what you want.
A switching regulator (“buck” regulator for lowering voltage, “boost” for raising it) will always have an inductor in the circuit.
In obscure circumstances (that you won’t find on a quad currently) that inductor may be part of a silicon die inside a chip, but there will always be something performing that function.

So if there’s no inductor, it’s linear.
If there’s a single big IC with 2-3 legs (and sometimes a metal tab) thats almost always a linear regulator even if it has an inductor, or it’s an ancient switching design you don’t want to use anyway.

Long story short: you’re right on the money!