Claims
- 1. A rotational speed control system including:
- an electric motor comprised of a cylindrical rotor disposed within a hollow cylindrical stator;
- motor control means electrically connected to the stator for sending an electrical current therethrough and producing a corresponding rotational movement of the rotor;
- reflective photoelectric means disposed within the stator for sensing rotational movement of the rotor and producing corresponding electrical output signals; and
- speed monitoring circuit means connected electrically to the photoelectric means and the motor control means for measuring the rotational speed of the rotor and sending regulatory electrical signals to the motor control means.
- 2. A motor speed control system as set forth in claim 1 wherein the photoelectric means includes an annular array of alternate light reflective spots and light absorbent areas circumferentially disposed on the rotor.
- 3. A motor speed control system as set forth in claim 2 wherein the photoelectric means includes a light source and a photosensitive device optically coupled to a common reference area of the array.
- 4. A motor speed control system as set forth in claim 3 wherein the light source and the photosensitive device are angularly disposed with respect to one another and are supported within the stator.
- 5. A motor speed control system as set forth in claim 4 wherein said stator includes a pole piece and the light source and the photoelectric device are supported within respective apertures in said pole piece.
- 6. A rotational speed control system including:
- an electric motor comprised of a cylindrical rotor and an electromagnetic field producing means surrounding a portion of the rotor for directing a field of magnetic flux through said portion and rotating said rotor correspondingly;
- motor control means electrically connected to said electromagnetic field producing means for energizing said field producing means to produce a corresponding field of magnetic flux;
- photoelectric means supported within said electromagnetic field producing means for sensing rotation of said rotor and producing corresponding electrical signals; and
- speed monitoring circuit means connected electrically to said photoelectric means and said motor control means for determining the speed of rotation of said rotor and sending regulatory electrical signals to said motor control means.
- 7. A rotational speed control system including:
- an electric motor comprised of a hollow cylindrical stator and a cylindrical rotor having a portion disposed within said stator;
- motor control means electrically connected to said stator for sending an electrical current therethrough and rotating said rotor correspondingly;
- light reflecting means disposed on said portion of the rotor for reflecting light in accordance with the rotation of said rotor;
- optical means embedded in said stator for receiving reflected light from said light reflecting means and producing electrical signals corresponding to the rotation of said rotor; and
- speed monitoring circuit means connected electrically to said optical means and said motor control means for determining the speed of rotation of said motor and sending regulatory electrical signals to said motor control means.
- 8. A rotational speed control system as set forth in claim 7 wherein said optical means includes light source means disposed for receiving directing light onto said light reflecting means.
- 9. A system including:
- an x-ray tube comprised of an envelope having therein a cylindrical rotor, an anode target mounted for rotation on said rotor, and a cathode disposed to direct electrons onto said anode target;
- light reflective means disposed on an annular portion of said rotor for reflecting light radially of the rotor in accordance with the speed of rotation of said target;
- stator means disposed externally of said envelope and surrounding said annular portion of the rotor for magnetically coupling to said rotor and producing rotation of said target;
- optical means disposed within the stator means for receiving said reflected light and producing corresponding electrical signals; and
- electrical control means connected electrically between said optical means and said stator means for receiving said electrical signals and sending regulatory electrical signals to said stator means.
- 10. A system as set forth in claim 9 wherein said stator means includes means for shielding said optical means from radiation extraneous to light reflected from said reflective means.
- 11. A system as set forth in claim 10 wherein said optical means includes light transmitting means disposed for directing light onto said light reflective means and light detector means disposed for receiving light reflected from said light reflective means.
- 12. A system as set forth in claim 11 wherein said shielding means includes respective apertures disposed in the stator means for supporting the light transmitting means and the light detector means in optical alignment with the light reflective means.
- 13. A system as set forth in claim 9 wherein said cathode is heatable to incandescence and a portion of said anode target is disposed between said cathode and said light receiving means.
- 14. A system as set forth in claim 13 wherein said anode target comprises an axially rotatable disc having an outer marginal portion disposed between said cathode and said light receiving means.
- 15. In combination:
- an envelope;
- a cylindrical rotor mounted for axial rotation with the envelope;
- an electrode mounted on said rotor for rotation therewith;
- a light reflective means disposed on an annular portion of said rotor for reflecting light radially thereof in accordance with the speed of rotation of said target;
- a stator disposed externally of the envelope and surrounding said annular portion of the rotor;
- light receiving means embedded in said stator and optically aligned with said light reflective means for receiving light reflected therefrom and producing corresponding electrical signals; and
- control means connected electrically between said light receiving means and said stator for receiving said electrical signals from the light receiving means and sending regulatory electrical signals to the stator.
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a division of application Ser. No. 847,877, filed Nov. 2, 1977, now U.S. Pat. No. 4,225,787.
US Referenced Citations (6)
Foreign Referenced Citations (2)
Number |
Date |
Country |
2110017 |
Sep 1972 |
DEX |
2245950 |
Apr 1975 |
FRX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
847877 |
Nov 1977 |
|