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linear analog servo motor drive

ammar87

Jan 7, 2013
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Jan 7, 2013
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hello my friends
i am trying to build a linear analog servo drive for a servo motor and YES it is analog not a PWM for many reasons one of them :is that this drive is a part of control system i am working on and i want to reduce the noise to minimum.
so i dig the web and i found several power op amp: like L165,L2720, LM675,LM12
i am kid of confused because all i want is :
Class-AB linear power Amplifier with no distortion around zero
i am trying to use the power op-amp rather than power transistors to reduce the number of components and the issues related to them .
here is the motor specifications:
http://www.specamotor.com/en/Faulhaber/motors/2338-006S/datasheet_motor.html
i suppose to control the position in bi-direction.
the questions:
1-which power op-amp should i use?
2- is there a ready drive that i can buy ?
3-is this circuit correct to control the motor position in bi-direction?
cct.png

any help will be more than appreciated
 

duke37

Jan 9, 2011
5,364
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Jan 9, 2011
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5,364
That circuit looks OK. You will need a power supply of about +-7V to limit the motor voltage to 6V.

I have not looked up the data for the amps you mention but I have used a LA6500 (1A Maximum) for non audio purposes.

The DAC must be able to produce positive and negative outputs or you will need a level shifter.
 

ammar87

Jan 7, 2013
3
Joined
Jan 7, 2013
Messages
3
That circuit looks OK. You will need a power supply of about +-7V to limit the motor voltage to 6V.

I have not looked up the data for the amps you mention but I have used a LA6500 (1A Maximum) for non audio purposes.

The DAC must be able to produce positive and negative outputs or you will need a level shifter.
can this be useful?
OPA548_Servo_drive_f.png

i want to have position control
 

duke37

Jan 9, 2011
5,364
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If you want position control you will need some form of feedback to determine the position. Many years ago, model aircraft used potentiometers to indicate position. I do not know current technology in this area. A potentiometer can be used to provide a voltage to match that of the input when the position is correct.
 

ammar87

Jan 7, 2013
3
Joined
Jan 7, 2013
Messages
3
If you want position control you will need some form of feedback to determine the position. Many years ago, model aircraft used potentiometers to indicate position. I do not know current technology in this area. A potentiometer can be used to provide a voltage to match that of the input when the position is correct.
yes sure there is encoder involved to measure the angle and a computer with Data Acquisition Card used to implement the controller
 
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