Beavis

My Feedback: (19)

Greetings,

Basic question: when a servo is not being used to move a flying surface and provided that it is not working against any drag in its resting position, is there any difference in the amount of current it drains depending on whether it is centered or trimmed? I understand that the receiver is always sending pulses to the servo to instruct it to stay where it is, even when it is centered. Hence, I'd assume that, independently of whether the servo is providing some trim, or whether it is centered, the resting current drain would be the same. Am I correct?

Thank you in advance.

jaka

Hi!
If the servo isn't working ...there is only idle current (5-10mA) flowing through it.

Beavis

My Feedback: (19)

Hello Jaka,

Thank you.

I understood from your answer that the idle current is the same, regardless of whether the servo is centered, or not. Correct?

Thank you again.

dirtybird

My Feedback: (5)

The current the servo draws depends on the load it is subjected to.
If the trim is needed to center the surface it would reduce the load and draw less current
If the trim is needed to offset some aerodynamic force then the load will increase and the servo will draw more current

jaka

Hi!
If the servo is not working (motor not turning ) there is just idle current drawn by the servo.
As soon as the electric motor inside the servo is working more current is floating through the servo.

dirtybird

My Feedback: (5)

In the stalled condition the servo is drawing the maximum current. The motor is not turning in the stalled condition.

Beavis

My Feedback: (19)

Thank you both.

jaka

Hi!
...But it tries to turn which means lots of current flowing through the motor.

JoeAirPort

My Feedback: (41)

I think I understand your question. The plane is just sitting in place on the ground...tx and rx are on. The servos are all holding position.

My answer is no. The servo does not have a magic center position that draws a different current than any other position. The only thing loading the servo is the aileron weight or elevator weight. So if you are a few clicks off center it makes no change in load on the servo. The center position is determined by the pulses sent from the rx which is determined by the tx. It's just a hypothetical position that happens to be the center of throw on your airplane. The servo center position can be anywhere on the range of motion of the servo.