300km

7.4V servo power

Posted by moglos on June 5, 2016 at 8:54pm

Hi, I'm a bit confused by the options to run servos at 7.4V on a Pixhawk.

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This warning appears on the page http://ardupilot.org/plane/docs/common-powering-the-pixhawk.html#powering-backup-off-the-servo-rail

and confirms you can do it, but doesn't offer any info on how. Do I just plug in a 7.4V BEC to the servo rail and it will power the servos at 7.4V but not offer any power for the Pixhawk? (I'm using the Pixhawk power module anyway).

Other suggestions I've seen suggest I shouldn't plug the BEC +ve lead into the Pixhawk servo rail. I should remove the servo +ve leads from the servo plugs and connect them straight to the BEC +ve output. The BEC -ve output should be connected to a -ve terminal on the Pixhawk servo rail. And the servo plugs (with only the signal and -ve wires left) should be plugged to the Pixhawk.

Any help appreciated.

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Replies

  • iskess June 5, 2016 at 10:26pm
    Just plug in the high voltage right into the servo rail. However you will lose the feature of a redundant power source for the Pixhawk if the power module somehow were to fail.
    There is no advantage to removing the BEC + wires from the servo rail unless you have some other 5v power source you want to use just for the redundancy feature.
    • 300km
      moglos > iskess June 6, 2016 at 4:41am

      Thanks, I'm pleased it's that simple.

      (It's a pity the setup details don't spell it out. I'd spent hours researching it before writing this post)

This reply was deleted.