TALP1000B hard stop

Hi Mike,

The TALP1000B does have mechanical rotation stops. These stops limit the maximum rotation angles to a value between 5 and 6 degrees.

Regards,

Arthur

Arthur,

do you have a drawing of the position and size of the these stops?

Thanks,

Mike

Hi Mike,

The rotation stops are an integral part of the design. The TALP1000B has 8 magnets which (in conjuction with the 4 drive coils) provide the torgue required for rotation. Four magnets are easily visible on the reflective mirror side and 4 additional magnets are attached to the underside of the Si mirror and gimbals. As the Si mirror or gimbals rotate these magnets move in and out of the quiescent mirror plane. Rotation is stoped when the underside magnets touch the ceramic circuit board below. We do not typically supply detail drawings of this portion of the assembly.

Regards,

Arthur

Hi Arthur,

thanks for the very informative answer.

Mike

Can the mirror hinges be damaged (any fatigue, cracking) after repeatedly touching the hardstop and going a bit over (applying 0.5-1% more current than needed to rotate miror to touch the hardstop?)

Also, during the rotation does the mirror sag? E.g. having not only rotattional, but also downward translational movement?

Hi Mike,

TI recommends that the TALP1000B be operated within the data sheet operational angle specification which is +/-5 degrees mechanical for both axis. All qualification and reliability testing was restricted to this angle range. The mirror hinges can be damaged if a current corresponding to large angle (beyond the stops) is applied as an abrupt  step. The damage mechanism is fracture rather than fatigue.

As part of product characterization, we did make contact with the roation stops on a reqular basis and found that it is possible to approach the hard stop in a controled current scan and touch without hinge damage but TI did not include this operation in any reliabillity test.ing Therefore, TI can not quantify how "repeatedly" this process can be performed.

Regards,

Arthur

Hi Mike,

The TALP1000B uses a push/pull type actuator. The coil winding and magnet polarities are arranged so that coil current pushes up on one magnet and pulls down on the other. There is no force on the rotation axis so there should be no sag. The previous statement is strictly true only for small angles. As the mirror rotates, the pull force is larger than the push force and a net force is produced on the mirror. The angles are small and the moment arm for the applied force is large so the displacement of the mirror in the z direction should be small. We have not measured this displacement.

Regards,

Arthur