Does anyone know of a sensor that determines position, feeds back a
signal
to both allow position and preselection of motion? I am trying to
fabricate
a flap handle that when put in a position (say 30 deg flaps)
actuates the
motor; the sensor senses when the motor (flap) is there and then
shuts off.
Seems to me cowl flap linear actuators might do that? But I already
have a
motor and a way to sense flap position. I just need to feed it back
and
control it at the flap handle.
Marc

Any potentiometer will work as a sensor.
http://parts.digikey.com/1/parts-kws/a-250k-potentiometer

Paul Lamar

Out put stage attached. The word I was looking for was voltage
divider for the flap position selector switch. You will need a pot
with as many turns as ball screw shaft (or proportional gearing).
C. Smith

Paul,

Here is a decidedly simple and low-tech way to accomplish it:  let
us define a "knife" type switch as consisting of female "contacts"
and a male "blade" which closes an electrical circuit when the blade
slides between the con- tacts.  The blade is directly attached to
the flap position indicator, visible through a slot on the panel.

Two sets of contacts are attached to the flap actuator handle...one
set above, and another set below, with a gap in bet- ween.  When the
flap actuator handle is moved, it engages the blade and the flaps
move until the blade reaches the end of the contacts and then stops.

The upper set of contacts make the flap go down, the lower set
makes the flap go up.  If you don't want to route the actual flap
motor current through the panel, you can use relays.  I am not sure
how this device will function when the blade is exactly at the end
of the contacts, whether there will be intermittent contact,
sparking etc.  but I am sure there are many ways to deal with these
issues.  For example, you could spring-load the blade so that once
it reaches the end of travel, it will tend to self-release even
further.  Hope this idea spurs us on to much better ones.

Gene Kahn

Try EFI throttle position or pedal position sensors, working through a
comparator. Output through an amp as per C. Smith. Parts are fairly
inexpensive and readily available. Just need to adapt them.

Dale Davies