초록 ▼

An electric machine or assembly 10 including a housing 12, a stationary stator 14, two substantially identical and opposed rotors 16, 18, and a pair stationary field coils 22, 24. Field coils 22, 24 are selectively energizable to controllably vary the flux generated by assembly 10, thereby allowing

An electric machine or assembly 10 including a housing 12, a stationary stator 14, two substantially identical and opposed rotors 16, 18, and a pair stationary field coils 22, 24. Field coils 22, 24 are selectively energizable to controllably vary the flux generated by assembly 10, thereby allowing assembly 10 to provide a relatively constant output torque, power, or voltage over a relatively wide range of operating speeds.

대표청구항 ▼

An electric machine or assembly 10 including a housing 12, a stationary stator 14, two substantially identical and opposed rotors 16, 18, and a pair stationary field coils 22, 24. Field coils 22, 24 are selectively energizable to controllably vary the flux generated by assembly 10, thereby allowing

An electric machine or assembly 10 including a housing 12, a stationary stator 14, two substantially identical and opposed rotors 16, 18, and a pair stationary field coils 22, 24. Field coils 22, 24 are selectively energizable to controllably vary the flux generated by assembly 10, thereby allowing assembly 10 to provide a relatively constant output torque, power, or voltage over a relatively wide range of operating speeds. series in a first connection state and supplying thereto an external power supply voltage to be charged thereby, and for coupling the N capacitors in parallel in a second connection state; and varying means for varying a duty ratio of a charging timing of the N capacitors in the first connection state, so as to output an internal power supply voltage which is variable, wherein said varying means of said DC-DC converter includes a comparator which generates an output pulse by comparing the internal power supply voltage and a reference voltage, and a switch having an ON/OFF state controlled by the output pulse and supplying the external power supply voltage to the N capacitors or to one of the N capacitors. 10. The storage apparatus as claimed in claim 9, wherein said storage section includes a head and a recording medium, and said DC-DC converter further comprises reference voltage generating means for generating a reference voltage which is different depending on a recording and/or reproducing position of the head on the recording medium. 11. The storage apparatus as claimed in claim 9, wherein said DC-DC converter further comprises reference voltage generating means for generating a reference voltage which is different depending on a data transfer rate of said internal circuit. 12. A storage apparatus comprising: an internal circuit; a storage section; and a DC-DC converter which supplies an internal power supply voltage to said internal circuit, said DC-DC converter comprising: switching means for coupling N first capacitors having identical capacitances in series, and coupling M second capacitors in parallel to each other and in parallel to the N first capacitors in a first connection state, and supplying thereto an external power supply voltage to be charged thereby, and for coupling the N first capacitors in parallel to each other and the M second capacitors in series to each other and in series to the N first capacitors in a second connection state; and varying means for varying a duty ratio of a charging timing of the N first capacitors and the M second capacitors in the first connection state, so as to output an internal power supply voltage which is variable, wherein said varying means of said DC-DC converter includes a comparator which generates an output pulse by comparing the internal power supply voltage and a reference voltage, and a switch having an ON/OFF state controlled by the output pulse and supplying the external power supply voltage to the N capacitors or to one of the N capacitors. 13. The storage apparatus as claimed in claim 12, wherein said storage section includes a head and a recording medium, and said DC-DC converter further comprises reference voltage generating means for generating a reference voltage which is different depending on a recording and/or reproducing position of the head on the recording medium. 14. The storage apparatus as claimed in claim 12, wherein said DC-DC converter further comprises reference voltage generating means for generating a reference voltage which is different depending on a data transfer rate of said internal circuit.