[simpits-tech] Using pots for position sensing

[Gene Buckle]

>
> But.. and the big but is - how to physically operate the pot? With rotary
> pots it's hard to get a full sweep, impossible if you try to use a simple
> bell-crank setup. And linear pots are generally fairly fragile so you
> don't want to put any strain on either end of it's movement.
>

I've fought that particular monster myself recently.  Without using gears, 
or some other mechanical system, there's just no easy solution to it.

However, in doing research for an article I've ordered some VERY cheap 
hall effect sensors (about $1.50 each).  I found about them when I was 
checking to see how close Mike was getting to finishing his book. :)

Head over to http://www.mikesflightdeck.com and scroll down to the section 
titled "Position Sensors Chapter Revisions (3 September 2008)" and also 
the section marked "Control Yoke Chapter Progress and Hall Sensors (20 
June 2008)"  The second section goes into detail on how the bits go 
together.  The setup he illustrats is very simple and pretty much deletes 
a whole bunch of mechanical linkages required to turn a pot.  I've got a 
pile of .125" neodymium magnets that I'm going to try this with to see how 
well it works.  If they're not enough I can always hit the local hardware 
store for ones like he's using.

Digikey carries the Allegro A1301 parts in stock.  (you want the SIP 
version, not the surface mount of course)

g.



-- Proud owner of F-15C 80-0007
http://www.f15sim.com - The only one of its kind.