RC Servo kicking at start up

Robotics and electronics discussion Mechanical design and actuators
1

Hi,

Has anyone had their RC servo kick when turning on their orangutan SVP324 controller.

I have a pan & tilt servo which is kicking when the orangutan is switched on. The tilt servo jumps
to one end of its range everytime the power button is pushed to turn ON.
It is a metal mesh, high speed, high power RC servo. The
pan servo doesn’t jump as it is a parallax continuous rotation servo from Pololu.I am guessing
that is because the continuous rotation servo has had its feedback potentiometer removed.

Currently servos are receiving VCC through the jumper setting on the regulated power side of the board.
If I use the adjustable power feature to say 6V (via the designated trimpot) it jumps just the same.

What is required to stop this tilt servo from jumping. Capacitor?

Any advise would be appreciated.

Carl.

2

Carl,

I don’t think there’s much you can do about that. What happens when you just apply power to the servo? Most servos I’ve seen twitch when you connect power.

- Jan

3

Jan,

When I apply power directly to the servo, it twitches, but no where near as much
as what I have noticed when connected through the SVP.

Its not a major problem, it just means I will have to compensate for it in the software.

Thank you.

Carl.

4

Carl,

Which servo port are you using for this twichy servo? Do you see the same behavior if you plug it into a different port?

- Ben

5

Ben,

Currently using servo ports and 0-1 and also tried 6-7. Same initial kick.

Using Vadj regulated supply and adjusted the trimpot to give me 6V (checked with multimeter).

I dont think it makes much of a difference, but I should point out that I am currently using a Lab DC power supply (rated to 2.5A) which
is currently supply the SVP at about 9.6 Volts. From the power supply, the LCD current consumed is about 110-120mA. Connected are the
board, MCU, two servos, a sharp IR and EZ0 sonar sensor. RP5 motors are disconnected.

Even when using the Maestro 6 channel servo controller, I noticed that servos also twitch in the same way.

Carl

6

It sounds to me like you’re just seeing the way your servos react when power is applied.

- Ben