Desperately seeking clarification

Finishing a new quad using Pixhawk with OPTO ESC's. Therefore, I'm using a seperate BEC(power control module for actual autopilot). I have no servos since it is a quadcopter. Do I still need to use a Zener Diode?

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  • I should probably add I have all wires from ESC's in rail. I was informed since OPTO I can do that. The quad is flying and well but I spent a fortune on it and too nervous to fly unless get this resolved.
    • Thanks for clarification and I have read the link about 50 times prior but there was no direct answer. I do understand if I have a spike the rail will lose power and I'll crash. I guess the question now is how likely is it I'll have a 5.7 volt spike? I am using the power control module to power the actual autopilot since I am only running 4s.
    • Developer

      That's ok as you have only one power source on the servo rail from the BEC Each Opto ESC is a sink for power. ESCs with built in BEC source multiple power, so can conflict, hence only one should have the power line connected (at most), the others should be all disconnected.

      As for the requirement for the Zener, read this

      What it's saying is that if the voltage spike on the servo rail above 5.7V it will disconnect power to the pixhawk. If you have both PowerModule and BEC connected, it will have redundancy. Solution would be to have the power module connected, or another 5V BEC connected to the Power Module port. (i'm guessing you need a PM that is more than 4S capable)

      Hope that helps:)

  • Since my ESC's are OPTO I have a BEC connected to rail BUT that's it. Just ESC's and a BEC.
  • MR60

    The answer, yes or no, depends on what you have connected on your servo rail. Did you connect a BEC on it or any other electronic components, apart from your ESCs signal+ground wires ?

  • Thank you and no doubt...this needs to be clarified. I'm not kidding when I tell you I've asked 50 people, 4 drone shops, and countless hours of research. Half the people said, "Yes!"
  • No
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