12-12-2016, 06:31 PM
Here's some info about scale's which I have been working on for some while.
The sensors are built out of a tube filled with ballbearing ball's and a set of induction and pick-up coils.
The theory which the sensors use is that of an LVDT.
By inducing a sine wave voltage in the induction coil, the pick-up coils generate an other sine wave which you can shift 360deg. per ball which they move over on.
The total cost for 3 sensors of +-1meter + board is approx. 100€ at this moment. This does not include the necessary tools (soldering iron, scope, ...).
The downside of this sensors is that at the moment every single sensorcoil needs a callibration file which takes houres to make. I'm hoping that by increasing the stability of the board I will be able to overcome this backdraw.
This weekend I was able to make my fist stable reading and calculation. This with a resolution of .008mm. By fine tuning the claculations in the mcu I should be able to get this up to .002mm.
Since I'm not an electronics engineer everything was based on trial and error, and a lot of searching and reading on the internet.
If there is anyone who can provide some feedback on how to increase stability of the board, simplify the schematics, ... etcetc I would be very grateful.
The sensors are built out of a tube filled with ballbearing ball's and a set of induction and pick-up coils.
The theory which the sensors use is that of an LVDT.
By inducing a sine wave voltage in the induction coil, the pick-up coils generate an other sine wave which you can shift 360deg. per ball which they move over on.
The total cost for 3 sensors of +-1meter + board is approx. 100€ at this moment. This does not include the necessary tools (soldering iron, scope, ...).
The downside of this sensors is that at the moment every single sensorcoil needs a callibration file which takes houres to make. I'm hoping that by increasing the stability of the board I will be able to overcome this backdraw.
This weekend I was able to make my fist stable reading and calculation. This with a resolution of .008mm. By fine tuning the claculations in the mcu I should be able to get this up to .002mm.
Since I'm not an electronics engineer everything was based on trial and error, and a lot of searching and reading on the internet.
If there is anyone who can provide some feedback on how to increase stability of the board, simplify the schematics, ... etcetc I would be very grateful.