Stepper motor motion sensor

Claim 2

Apparatus for detecting operation of a stepper motor rotor in response to the energizing of the motor stator windings by excitation signals presented to the motor in each step interval from an excitation signal source, as characterized by: means responsive to said excitation signal source, for providing inactive winding signals in each present step interval in response to the excitation signals presented to the motor, said inactive winding signals identifying the motor stator windings which are not energized in either the present step interval or in the immediately preceding step interval; and voltage measuring means, responsive to each of the motor stator windings and responsive to said inactive winding signals, for providing a signal manifestation of stepper motor operation in dependence on the amplitude value of the voltage signal induced in one or more of said inactive stator windings in response to the energizing of the motor stator windings in each present step interval.

Claim 3

The apparatus of claim 1, wherein said voltage measuring means provides said signal manifestation of stepper motor operation in dependence, alternately, on the amplitude value of said induced voltage signal being greater than or less than a defined amplitude value.

Claim 4

The apparatus of claim 2, wherein said voltage measuring means provides said signal manifestation in response to an amplitude value of said induced voltage signal which is less than said defined amplitude value, said signal manifestation being indicative of the actual movement of the stepper motor rotor in response to the excitation signals presented to the motor in said present step interval.

Claim 5

The apparatus of claim 2, wherein said voltage measuring means provides said signal manifestation of stepper motor operation in dependence on an amplitude value of said induced voltage signal being greater than said defined amplitude value, said signal manifestation being indicative of the non-rotation of the stepper motor rotor in response to the excitation signals presented to the motor in said present step interval.

Claim 6

The apparatus of claim 1, wherein said means responsive to said excitation signal source, comprises: first means, for providing active winding signals in response to the excitation signals presented to the motor in each present step interval, said active winding signals identifying the motor stator windings to be energized in the present step interval together with the stator windings which have been energized in the immediately preceding step interval; and second means, responsive to said first means, for providing said inactive winding signals in the presence. of each of said active winding signals, said inactive winding signals identifying the stator windings not energized in either the immediately preceding interval or in the present step interval.

Claim 8

Apparatus for detecting operability of a four phase stepper motor having four stator windings, in response to the energizing of successive pairs of stator windings in successive step intervals by excitation signals presented to the motor from a source of excitation signals, each pair of stator windings energized in each present step interval including one of the pair of stator windings energized in an immediately preceding step interval, as characterized by: means responsive to the excitation signal source for providing, in each present step interval in response to the excitation signals presented to the motor, an inactive winding signal identifying the stator winding which is not energized in either the present step interval or in the immediately preceding step interval; and voltage measuring means, responsive to the four motor stator windings and responsive to said inactive winding signal, for monitoring, in each present step interval the inactive stator winding identified therein by said inactive winding signal, and for providing a signal manifestation of stepper motor operation in dependence on the amplitude value of the voltage signal induced in said monitored inactive winding in response to the energizing of the selected pair of motor stator windings by the excitation signals presented in said present step interval.

Claim 9

Apparatus for detecting operability of a four phase stepper motor having four stator windings, in response to the energizing of successive pairs of stator windings in successive step intervals by excitation signals presented to the motor from a source of excitation signals, each pair of stator windings energized in each present step interval including one of the pair of stator windings energized in an immediately preceding step interval, as characterized by: means responsive to the excitation signal source for providing, in each present step interval in response to the excitation signals presented to the motor, an inactive winding signal identifying the stator winding which is not energized in either the present step interval or in the immediately preceding step interval; and voltage measuring means, responsive to the four motor stator windings and responsive to said inactive winding signal, for monitoring, in each present step interval the inactive stator winding identified therein by said inactive winding signal, and for providing a signal manifestation of stepper motor operation in dependence on the amplitude value of the voltage signal induced in said monitored inactive winding in response to the energizing of the selected pair of motor stator windings by the excitation signals presented in said present step interval.

Claim 10

The apparatus of claim 7, wherein said voltage measuring means provides said signal manifestation as an indication of the actual rotation of the stepper motor rotor in response to the excitation signals presented in each present step interval, in dependence on an amplitude value for the induced voltage signal in said identified inactive stator winding which is less than that of a defined amplitude value.

Claim 11

The apparatus of claim 7, wherein said voltage measuring means provides said signal manifestation as an indication of the non-rotation of the stepper motor rotor in response to the excitation signals presented in each present step interval, in dependence on an amplitude value for the induced voltage signal in said identified inactive stator winding which is greater than that of a defined amplitude value.

Claim 14

The method of claim 10, wherein the step of providing comprises the steps of: monitoring, in each present step interval, at least one of said inactive stator windings identified therein, and measuring the amplitude value of said induced voltage signal; comparing the measured amplitude value in each present step interval with that of a defined amplitude value; and - determining the operation of the stepper motor in dependence on the relative value of said measured amplitude value with respect to said defined amplitude value, and providing said signal manifestation in representation of said determination.

Claim 15

The method of claim 11, wherein said step of determining includes providing said signal manifestation in response to the presence, in a present step interval, of a measured amplitude value less than that of said defined amplitude value, said signal manifestation being indicative of the actual rotation of the stepper motor rotor in said present step interval.

Claim 16

The method of claim 11, wherein said step of determining includes providing said signal manifestation in response to the presence, in each present step interval, of a measured amplitude value greater than that of said defined amplitude value, said signal manifestation being indicative of the non-rotation of the stepper motor rotor in said present step interval.