Stepping motor drive method and apparatus

Claim 1

A method for exciting each phase winding in a stepping motor having an arbitrary number of phase windings, the method comprising the steps of: applying a DC source voltage of a DC source to a selected phase winding at a voltage level substantially higher than the intended operating voltage of said winding to rapidly increase inductive load current in said phase winding; thereafter pulse modulating the DC source voltage; thereafter removing the DC source voltage from said phase winding at a predetermined time; directing said inductive load current through the DC source in a sense opposing the source current to rapidly decrease said inductive load current; and repeating the applying, modulating, removing and directing steps for each said phase winding.

Claim 2

A method for exciting each phase winding in a stepping motor having an arbitrary number of phase windings, the method comprising the steps of: applying a DC source voltage of a DC source to a selected phase winding at a voltage level substantially higher than the intended operating voltage of said winding to rapidly increase inductive load current in said phase winding; thereafter pulse modulating the DC source voltage; thereafter removing the DC source voltage from said phase winding at a predetermined time; directing said inductive load current through the DC source in a sense opposing the source current to rapidly decrease said inductive load current; and repeating the applying, modulating, removing and directing steps for each said phase winding.

Claim 5

A method for sequentially exciting individual inductive windings of a polyphase stepping motor with a single DC power source comprising the repeated steps of: (a) establishing a first current path between a first terminal of a first winding and a first terminal of a DC power source which is characterized by a source voltage substantially higher than an intended operating voltage of said winding; (b) establishing a second current path between a second terminal of said first winding and a second terminal of the power source for a limited initial time interval to form a current-carrying circuit through said first winding, whereby the power source causes a rapid increase of current through said winding; (c) thereafter periodically interrupting the second current path according to a predetermined duty cycle proportional to the ratio of the intended operating voltage and the source voltage and directing current to the first power source terminal; and (d) simultaneously interrupting the first and second current paths after steps (a) and (b) and directing the current to the first power source terminal and from the second power source terminal.

Claim 6

A method for sequentially exciting individual inductive windings of a polyphase stepping motor with a single DC power source comprising the repeated steps of: (a) establishing a first current path between a first terminal of a first winding and a first terminal of a DC power source which is characterized by a source voltage substantially higher than an intended operating voltage of said winding; (b) establishing a second current path between a second terminal of said first winding and a second terminal of the power source for a limited initial time interval to form a current-carrying circuit through said first winding, whereby the power source causes a rapid increase of current through said winding; (c) thereafter periodically interrupting the second current path according to a predetermined duty cycle proportional to the ratio of the intended operating voltage and the source voltage and directing current to the first power source terminal; and (d) simultaneously interrupting the first and second current paths after steps (a) and (b) and directing the current to the first power source terminal and from the second power source terminal.

Claim 10

An apparatus for controlling the excitation of a stepping motor having an arbitrary number of phase windings, said apparatus comprising: means for establishing a first current path between a first terminal of a winding and a first terminal of a DC power source characterized by a voltage substantially higher than the intended operating voltage of said winding; means for establishing a second current path between a second terminal of said first winding and a second terminal of said power source to form a circuit for carrying current through said winding; means for periodically interrupting said second current path according to a predetermined duty cycle after said circuit has been formed and for directing said current to said first power source terminal; means for simultaneously interrupting said first and second current paths; and means for directing current in said winding to said first power source terminal and from second power source terminal.

Claim 11

An apparatus for controlling the excitation of a stepping motor having an arbitrary number of phase windings, said apparatus comprising: means for establishing a first current path between a first terminal of a winding and a first terminal of a DC power source characterized by a voltage substantially higher than the intended operating voltage of said winding; means for establishing a second current path between a second terminal of said first winding and a second terminal of said power source to form a circuit for carrying current through said winding; means for periodically interrupting said second current path according to a predetermined duty cycle after said circuit has been formed and for directing said current to said first power source terminal; means for simultaneously interrupting said first and second current paths; and means for directing current in said winding to said first power source terminal and from second power source terminal.