Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
262 words
A control system for an electric motor having a rotor including at least two poles forming a rotor pole pair, and a stator including at least two poles forming a stator pole pair, each stator pole having a first and a second bifilAr winding and power supply and control means for energizing said stator windings to provide magnetic polarization zones each including two adjacent field regions of opposite magnetic polarity, which zones are periodically reversed to form a rotating magnetic field for driving the rotor, characterized in that said power supply and control means comprises an alternating current source having a frequency of at least several multiples of the rate of zone reversal at maximum motor speed; switching means connecting said alternating current source to the first bifilar winding of each stator pole for energizing same with a plurality of half-cycle alternations of one sign when a reference point on the rotor arrives at the beginning of one zone of the stator; said switching means connecting said alternating current source to the second bifilar winding of each stator pole for energizing same with a plurality of half-cycle alternations of opposite sign when the said reference point on the rotor arrives at the beginning of the next, oppositely polarized zone of the stator; and torque control means controlling said switching mean to control the time of initiation of energization of the energized bifilar windings during each of said half-cycle alternations of said alternating current source, said energized windings being automatically deenergized by said switching means at the end of each said halfcycle alternations.
Claim 2
Dependent Claim
262 words
A control system for an electric motor having a rotor including at least two poles forming a rotor pole pair, and a stator including at least two poles forming a stator pole pair, each stator pole having a first and a second bifilAr winding and power supply and control means for energizing said stator windings to provide magnetic polarization zones each including two adjacent field regions of opposite magnetic polarity, which zones are periodically reversed to form a rotating magnetic field for driving the rotor, characterized in that said power supply and control means comprises an alternating current source having a frequency of at least several multiples of the rate of zone reversal at maximum motor speed; switching means connecting said alternating current source to the first bifilar winding of each stator pole for energizing same with a plurality of half-cycle alternations of one sign when a reference point on the rotor arrives at the beginning of one zone of the stator; said switching means connecting said alternating current source to the second bifilar winding of each stator pole for energizing same with a plurality of half-cycle alternations of opposite sign when the said reference point on the rotor arrives at the beginning of the next, oppositely polarized zone of the stator; and torque control means controlling said switching mean to control the time of initiation of energization of the energized bifilar windings during each of said half-cycle alternations of said alternating current source, said energized windings being automatically deenergized by said switching means at the end of each said halfcycle alternations.
Claim 3
Dependent Claim
140 words
A control system as defined in claim 1, wherein said system further includes a DC voltage source, said switching means effecting an electrical connection between said second bifilar winding of each stator pole and said DC voltage source during the time the rotor is disposed in said one polarization zone of the stator, and further, reflecting an electrical connection between said first bifilar winding of each stator pole and said DC voltage source during the time said rotor pole is disposed in said next, oppositely polarized zone of the stator; and unidirectional conducting devices connected between said bifilar windings and said DC voltage source, said device being poled to permit conduction from the bifilar windings to the DC voltage source only when the bifilar windings are not connected to said alternating current source to facilitate magnetic recovery of the windings.
Claim 4
Dependent Claim
17 words
A control system as defined in claim 2, wherein said DC voltage source is a rechargeable battery.
Claim 5
Dependent Claim
28 words
A control system as defined in claim 1, wherein said electric motor is a brushless permanent magnet motor including a permanent magnet rotor rotatable disposed within said stator.
Claim 6
Dependent Claim
38 words
A control system as defined in claim 1, including further means for selectively connecting together all said first bifilar windings in series or parallel, and for selectively connecting together all said second bifilar windings in series or parallel.
Claim 7
Dependent Claim
56 words
A control system as defined in claim 1, wherein said switching means includes silicon-controlled rectifiers supplied by said alternating current source so as to be conducting only during one half-cycle alternations thereof, and gating means controlled by said torque control means and controlling the initiation of conduction of said silicon controlled rectifiers during said half-cycle alternations.