Both powerbus outputs at 5.9v but servo outputs at 7.4?

  • Hello,

    I have a small skymaster A10.

    I’m using the royal with a Pwm unit in the tail connected to output A.

    I’m using a splitter and a pwm unit in each wing.

    It is exactly the configuration here


    The tail unit is connected to output A.

    Is it possible to have both powerbus outputs at 5.9v BUT the output A servos fed by 7.4V from the powerbox servo outputs?

    I have three reasons to ask 1) I have a HV servo on the nose leg 2) I can run my lighting controller power supply from the powerbox and not directly from the battery and 3) my electron gear controller can then be fed from the powerbox rather than directly from a battery.

    Thanks in advance.

  • You will be able to set for handling both 5.9 and 7.4 volts; the PowerBus and direct outputs have an A side and a B side that will maintain the separate voltages.

    If you want to have all of your PowerBus connected servos at 5.9v you will need to use a single side of the PowerBus output with a splitter inline

    to send one output to the wing splitter and the other to the tail hub.

    This would free up the other bank to provide 7.4v to anything directly connected to this bank at the Royal servo outputs.

    For example:

    Bank A set to 5.9v for the PowerBus system

    -you would need 2 splitters and 3 hubs using only the PowerBus A output side

    Bank B set to 7.4v for directly connected HV servos, smoke, and lights.

  • Thanks guys.

    Two questions then.

    If one output is 5.9 and the other 7.4v, what voltage is supplied to each of the two Futaba receivers?

    (Reason I ask is the electron retract controller has a S-bus input. I plan to connect one of the Futaba receivers s-bus output to the electron retract controller which will  supply power to the HV steering servo.)

    Second question, if I do change and use an additional splitter, my set up would be

    Output A supplies

    1st splitter

    Which feeds another splitter which supplies two pwm units in each wing


    Connects to PWM splitter in the tail.

    Total setup from output A would be 2 splitters and 3 Pwm units.

    Except for the complexity of one additional splitter is there any disadvantage doing this?

    (For reference powerbus A would then supply 4 jr8411 servos, 2 jr 8711 2 jr 9411 and two midi size jr servos)

  • The PowerBus system was designed to support the daisy-chain type setup you would need; With 2 regulators per side you still have power redundancy so there is no real disadvantage.

    The receivers will take voltage from Bank B, so in my example they would be getting 7.4v from the RX1 and RX2 ports