Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: redruff on May 21, 2010, 07:41:28 PM

Title: Servo Jitters
Post by: redruff on May 21, 2010, 07:41:28 PM
Hello,
I need to use a linear servo so I got a hold of this one
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10951 (http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10951)

The problem is..when I suppply 6V power from  a battery pack it jitters really bad.
I hooked it to a stamp and I get it to move but I can never get the jitters out of it.
Any ideas?
What is under the shrink tube? Is it a PWM conversion circuit and could that be causing the problems?
Thanks
Title: Re: Servo Jitters
Post by: Soeren on May 21, 2010, 08:49:01 PM
Hi,

The problem is..when I suppply 6V power from  a battery pack it jitters really bad.
I hooked it to a stamp and I get it to move but I can never get the jitters out of it.
Any ideas?
First thing that should spring to mind when having a defective device would be to contact the seller about it ASAP.


What is under the shrink tube? Is it a PWM conversion circuit and could that be causing the problems?
Again, the seller have a chance of knowing. How should others know, unless they have this very servo and want to possibly destroy it to tell you?
Contact the seller and ask for a correctly working device.
Title: Re: Servo Jitters
Post by: redruff on May 21, 2010, 08:52:42 PM
I don't think its defective...dude..

The circuit under the shrink tube is a common circuit..I've seen them on other servos...I believe it is a PWM filter or conversion circuit.
Thanks for the help!
Title: Re: Servo Jitters
Post by: Soeren on May 21, 2010, 09:16:00 PM
I don't think its defective...dude..
Well,... Dude... If it doesn't behave as it should, it's defective in my book, but if you think it's not, why do you ask?


The circuit under the shrink tube is a common circuit..I've seen them on other servos...I believe it is a PWM filter or conversion circuit.
You have a servo signal into the heat shrink and a DC motor and feedback pot hanging on the other end, so it isn't really rocket science to claim that it's not a PWM filter, but the servo controller proper, converting the servo signal to a servo position with position feedback from the (linear) pot under the slider.

No skin of my back, but if you don't wanna return it for a swap, you'll have to live with the jitter, if it's not your servo signal that is jittery.
Title: Re: Servo Jitters
Post by: redruff on May 21, 2010, 10:25:44 PM
problem solved,
thanks