shoutchen's blog View Details
Archive for January, 2010
Posted by shoutchen | Jan 04, 2010 @ 06:39 PM | 16,702 Views
Here is my idea for a micro sized servo/actuator with optional feedback.
I think that of these can be built that would match the performance
of the available smallest servos, which at this time is a .65 gram
servo that has 6mm throw with 10 grams of force.

Here is a link to that servo..which is a work or art no doubt ...

My idea uses no motor, but a couple of magnetic coils, aided
by using iron cores to make the magnetic fields larger for each coil.

The coils push against a pair of magnets to move the arm.

The arm has a magnet on one end which moves across the linear
hall effect sensors in a slide by technique. The hall effect sensors
are really tiny

A couple of centering springs keep it centered so it could be used
without feedback.

It could possibly be modified to use one coil/core/spring/magnet...

The second image is a microcontroller circuit for it that uses
an cpu, hbridge, and 3 hall effect sensors. This is variant of
the other servo/actuator circuit I posted on another project.
the CPU could also be a PIC chip as well...
I posted a schematic for a PIC too, with a lot of slide by sensors..

Here is a link to some pre-wound small coils that are availble...

The weight of those is .07 grams each and each one comes with two
1.5mm x .5 mm magnets. The ID of the coils is 3 mm
I have a picture of it below.

This...Continue Reading