The power supply must be able to supply the stall current of the servos, typically 1 Ampere or more. Servos draw that every time they start up, so budget 1 Ampere per moving servo to be safe.
USB generally can't do that, for even one servo.
The power supply must be able to supply the stall current of the servos, typically 1 Ampere or more. Servos draw that every time they start up, so budget 1 Ampere per moving servo to be safe.
USB generally can't do that, for even one servo.