In article , To-Email-Use-
says...
..That is the first 4 of a number of hits.
If the info in the semi datasheets are insufficient, then try to find
out what stepper motors are used,and attack their datasheets.

What good are truncated links?

Do you know about http://tinyurl.com/ ?

...Jim Thompson



I've seen two types of iris motors..

1.
A two phase much like a stepper where one coil becomes the mover and
the other a sensor for move detection, then they alternate their jobs
where is the other coil then becomes the mover and the first one is now
the sensor. There is what looks like a spur ring gear and two little
coils off the side which are the A and B phase and sensors shared.

2.

The spring type. tension spring keeps the iris in one position when
power is off. There is a PM that is attached to the linkage of the iris
and a coil near by that pulls it. Position is proportional to magnetic
strength in the coil. Also, the second coil is the damper coil, this
coil has DC current proportional to the velocity of the shutter to
create drag so not to allow iris to over shoot or wobble at the stop
point.

I am sure there maybe constant DC in the damper coil to prevent it from
shaking with normal handling.

I am sure there are other types out there like a PM motor directly
driving the iris. A lot of these camera's use the image center to adjust
the iris, they just open/close as they see fit from the image sensor and
use over current detection for stops or jam detection, which may get
mistaken for iris limits.

You need to research which system you're interested in. Maybe you're
trying to do all of them in a single chip?



Jamie