A bit of a comment about these "Reisner SAM's".
The Contact Blade that protrudes from the back of the Sam,
is electrically in contact with the Frame, and care must be taken because, Both on and off magnet coils are also Connected to that same frame. As far as I know, this
cannot easily be done
if you are using a matrix scan system. !
In the past I have and bolted a small solder
terminal strip to the back of each Sam.
Then carefully soldered a small reed-switch to the inside of each terminal strip,
I then cemented tiny magnets on each of the moving armatures, placed so that the magnet actuates the reed-switch when the tablet is on !
This is the a perfect fix for
this Reisner Problem.
Most other brands of SAM's do not have this problem.
I welcome other comments on this subject,
Though I have done many hundreds of these this way!
But beware, the Coils and moving contact blade
"
are definitely" common to each other electrically !
Best wishes, Mel