Another BEC question
 

OK, after reading ad nauseum about BEC wiring, and reading wiring diagrams, etc, I have a couple questions. First, from what I'm reading, there are basically two different camps on how to do this. This is for a dual ESC setup in an XR with a Futaba 4PL, btw.

1. (from Harley's diagram, among others). Power from battery to both ESCs and the BEC, power to the RX from the BEC, then run the servo off the RX. I know about removing the power wires from the ESCs to the RX.

My question here is how much power can the RX handle? I will be using a 7950 that can run @ 7.4V, so should I set the BEC for 7.4 or run it at 6? How much power does the RX use? Is it minimal or is it enough to make a difference at the servo?

2. Wire it like you do with a single ESC. In the Honcho, I have power run normally through the ESC and into the RX, with the BEC wired directly into the servo. The only wire from the servo to the RX is the signal wire.

My question here is, where does the power to the RX come from? Do you run one power lead from one of the ESCs and not from the other? If so, does this affect the LVC at all, or make them "non synchronized"?

I guess my main question is what is the disadvantage of running the RX off the BEC rather than bypassing it and running it directly to the servo? I'm assuming its loss of voltage, but how much?

you mention lvc (low voltage cutoff?) assuming you have lipo battery, then why not use an external cutoff. use one esc to power the receiver, disconnect the power wire from the other esc. then use a bec to supply the servo directly. I had some glitching when I used a bec, so spliced in an extra ground wire from the bec to the receiver.

if the receiver will handle 7.4 though just run the servo off that. it would be a lot simpler and doubt if there would be much voltage drop. disconnect power wires from both esc's though

I believe in Harley's thread there is the voltage info for the rx. That exact question was asked by numerous people. I know it is a crazy big thread to read, but it is in there.

He actually put the links to the posts in that thread in the very first post, I just never went back and reread it. :roll: Should have known he would have had it taken care of. It says the RX range is from 4.8V to 7.4V, so I should be fine setting the BEC at 7.4 if I run the RX off that then.