Does anyone know what kind of BEC I need for a Pixhawk 5X? I want to power the servo rails but there is very little information I can find on how to do it. It also must be separate from the PDB, as all pinouts on it are already in use. Can I just use a 5V battery or something? I know next to nothing about BEC’s by the way. Thanks.
It is better to use a BEC to provide a more stable power supply. I know little about this FC, but seeing their website, it seems to be a cheap copy of cubepilot ones.
Saying by the cubes, avoid powering your devices via the rail, I have experienced some noise trouble doing so to power hungry power servos.
Buy a great quality BEC like those provide by Mauch Electronics to power servos, they have a great line of products, and avoid your current from getting inside your FC circuit:
If you do not have any load being controlled by the outputs that are present on rail, no need to power it, it is used as a backup for stable planes and can help you very little with a multi-rotor power failure, be sure you are using good quality power sources to primarily power your FC.
It’s for a school design project, we were given the 5X, the cube is way beyond what they were willing to spend I guess. Thank you for the suggestion. The servo rail will be used to control two servos in a dual payload dropping mechanism for a hex drone by the way, so they need to be powered.
Ok, just try to avoid high current passing by the servo rail, you can keep your power lines away from the FC.
What do you think is the max current allowed to pass through the servo rail? Can’t seem to find info on that either.
I really don’t know, it can be dependent on each manufacturer design, but I would avoid more than 0,5A, I don’t think it is designed to carry on high currents.
If in doubt don’t pass any thru the servo rail. Power the servo’s directly.
I read online that the servo rail is rated for 10A, but I haven’t gone digging for a definitive source for that statement.
Even if it is true, you can risk a thousand dollar FC in case of a short-circuit when you could make simply wiring mods that wouldn’t cost you some bucks, I don’t know if it is worthy. Also, in my experience, I had some interference problems with my system induced by noise and peak power in the servo rail.