Position control feedback circuitry

Other Hardware Motors, Mechanics, Power and CNC
1

Hi guys. I'm going to be using 3 servo motors and 2 linear actuators for a project i am doing. would anyone be able to help me by providing an example of what kind of feedback circuitry I'll be needing to accomplish this? I'll probably be using a pot for the servo motors and an encoder for the linear actuators. I'll be using 12V motors.

Thanks in advance.

2

The easiest way to get feedback from a servo (which as you've obviously realised doesn't usually make that data public) is to use one like this from adafruit. I'm not sure how much of a range they have, or if other vendors have similar ones. The extra wire allows you to read the servo's actual position, it says.

3

JimboZA:
The easiest way to get feedback from a servo (which as you've obviously realised doesn't usually make that data public) is to use one like this from adafruit. I'm not sure how much of a range they have, or if other vendors have similar ones. The extra wire allows you to read the servo's actual position, it says.

OK , you just bought a custom made piece. But is there availablility of servo motors for online buy with the potentiometer wire coming out ???

4

Hi,

Can you post links to the specifications for your servos and actuators.

You usually don't need feedback for servos as they have it all biult in, you signal it to 90Deg and it turns to 90Deg, 10Deg and it turns to 10Deg.

Or are you getting mixed up with stepper motors.

Your actuator doesn't have a position feedback?

Tom... :slight_smile:

5

TomGeorge:
You usually don't need feedback for servos as they have it all biult in, you signal it to 90Deg and it turns to 90Deg, 10Deg and it turns to 10Deg.

That's not strictly true: if a servo is prevented from getting to the commanded position (say by being mechanically overloaded) it will know it didn't get there but you won't, unless the servo publicises its actual position ala the adafruit example.

6

Thanks for the help guys. I'm just asking basic questions as I go along with my project. Just trying to get a handle on what I'm getting myself into and what I'll exactly need. I'll update along the way.

Thanks again :slight_smile:

7

Servo motor or hobby servo?

8

Why do you need external feedback with a hobby servo? It should be at the position you told it to go to - unless it is undersized for the job.

...R