Powering pixhawk1

Can I power the servo rail with an additional 7.4 volt battery and zener diode. Would this reduce the voltage to 5 volts?
I want to output to 4 motors and 2 small servos.

Good day, the best voltage for power the servo rails is 5.32v…with this voltage you will not risk to damage or burn the voltage regulator.
Use a Zener diode without the right configuration will not work properly…you have more options for reduce the voltage…

I must say I am pretty confused as to what to do.
I have 4 motors plugged into pins 1 to 4 on the main out and 2 small servos plugged into pins 1 and 2 on the aux out.
Do I need two 5 volt power supplies, one for the main out and one for the aux out? and where do I plug the Zener?
If I need 2 power supplies can I use two from the esc’s bec?
If I need one power supply can I just use an esc bec, alternatively use a ubec from another battery and where do I plug it in? on the main out or the aux out.

Also I can’t see why its necessary to have the 2 servos connected to the aux out. When using the apm 2.6 they are all powered on the outputs rail.

If you want power the servo rails and at the same time provide redundancy, you can use an 3A ubec with a Vout of 5.30v and on it you can solder a capacitor and a Zener diode.
you can do the same using a different battery instead of use the one you are using for power your fc

Do you mean, in addition to the main power for the FC, I also supply power to the main out rail via an esc, and supply power to the aux rail via a 3A ubec via a different battery with Zener and capacitor.

Is the aux rail connected to the main rail? It seems it is sometimes when the voltage is 5 volts and not it above 5 volts?
Sorry for not understanding this.

in addition to your main battery, you can supply your fc with another battery with an ubec adding a capacitor with Zener.
pixhawk don’t supply power to the servo rails that’s why you can do it with an ubec…

Thank you, I think I have it now.