1. A system for controlling a remotely located electrical device comprising:
(a) a transmitter suitable to receive a first signal at a first voltage indicating the desired state of said electrical device and in response thereto provide an optical signal;
(b) an enclosure including a first device that selectively provides electrical power to said electrical device, wherein said electrical device is exterior to said enclosure, wherein said electrical power is approximately 120 volts or more;
(c) a receiver suitable to receive said optical signal and in response thereto selectively provide a second signal at a second voltage to said first device to provide said electrical power to said electrical device, wherein said transmitter and said receiver are maintained in a fixed relationship with respect to one another, wherein said transmitter is supported by said enclosure, wherein said transmitter is not located in said enclosure and
(d) wherein said optical signal passes from outside said enclosure to within said enclosure.
2. The system of claim 1 wherein said transmitter is located outside said enclosure.
3. The system of claim 1 wherein said receiver is located within said enclosure.
4. The system of claim 1 wherein said first signal is less than approximately 24 volts.
5. The system of claim 1 wherein the voltage of said first signal is less than the voltage of said second signal.
6. The system of claim 5 wherein the voltage of said first signal is approximately 24 volts and said second signal is approximately 120 volts.
7. The system of claim 1 wherein said transmitter and said receiver are free from including a mechanical switching mechanism.
8. The system of claim 1 wherein the optical path of said optical signal is free from receiving additional light from a source other than said transmitter.
9. The system of claim 1 wherein said optical signal is infra-red.
10. The system of claim 1 wherein said optical signal is at least one of modulated, includes a carrier signal, has different frequencies, pulsed.
11. The system of claim 1 wherein said optical signal is provided to a plurality of said receivers.
12. The system of claim 11 wherein each of said receivers is associated with a different electrical device to which power is selectively provided.
13. The system of claim 12 wherein each of said receivers determines if said optical signal is intended for its associated electrical device.
14. The system of claim 1 wherein said receiver is electrically connected to said first device in a manner free from a wire between a connector of said receiver and a connector of said first device.
15. The system of claim 1 wherein said receiver includes a line conductor, a load conductor, and is free from including a neutral conductor.
16. The system of claim 1 wherein said transmitter is proximate said enclosure.
17. The system of claim 16 wherein said receiver is proximate said enclosure.
18. A method for controlling a remotely located electrical device comprising:
(a) providing an enclosure including a first device that selectively provides electrical power to said electrical device;
(b) a transmitter receiving a first signal at a first voltage indicating the desired state of said electrical device and in response thereto providing an optical signal, wherein said electrical device is exterior to said enclosure;
(c) a receiver receiving said optical signal and in response thereto provides a signal at a second voltage to cause said first device to selectively provide said electrical power to said electrical device, wherein said electrical power is approximately 120 volts or more, wherein said transmitter and said receiver are maintained in a fixed relationship with respect to one another, wherein said transmitter is supported by said enclosure, wherein said transmitter is not located in said enclosure and said receiver is located in said enclosure; and
(d) wherein said optical signal passes from outside said enclosure to within said enclosure.
19. The method of claim 18 wherein said transmitter is located outside said enclosure.
20. The method of claim 18 wherein said receiver is located within said enclosure.
21. The system of claim 18 wherein said first signal is less than approximately 24 volts.
22. The method of claim 18 wherein the voltage of said first signal is less than the voltage of said second signal.
23. The method of claim 22 wherein the voltage of said first signal is approximately 24 volts and said second signal is approximately 120 volts.
24. The method of claim 22 wherein said transmitter and said receiver are free from including a mechanical switching mechanism.
25. The method of claim 18 wherein the optical path of said optical signal is free from receiving additional light from a source other than said transmitter.
26. The method of claim 18 wherein said optical signal is infra-red.
27. The method of claim 18 wherein said optical signal is at least one of modulated, includes a carrier signal, has different frequencies, pulsed.
28. The method of claim 18 wherein said optical signal is provided to a plurality of said receivers.
29. The method of claim 28 wherein each of said receivers is associated with a different electrical device to which power is selectively provided.
30. The method of claim 29 wherein each of said receivers determines if said optical signal is intended for its associated electrical device.
31. The method of claim 18 wherein said receiver includes a line conductor, a load conductor, and is free from including a neutral conductor.
32. The method of claim 18 wherein said transmitter is proximate said enclosure.
33. The method of claim 32 wherein said receiver is proximate said enclosure.
34. A system for controlling a remotely located electrical device comprising:
(a) a transmitter suitable to receive a first signal having a first voltage indicating the desired state of said electrical device and in response thereto provide an optical signal;
(b) an enclosure including a first device that selectively provides electrical power to said electrical device, wherein said electrical device is exterior to said enclosure;
(c) a receiver suitable to receive said optical signal and in response thereto selectively provide a second signal at a second voltage to said first device to provide said electrical power to said electrical device, wherein said electrical power is approximately 120 volts or more, wherein said transmitter and said receiver are maintained in a fixed relationship with respect to one another, wherein said transmitter is supported by said enclosure, wherein said transmitter is not located in said enclosure and is spaced apart from said receiver by a portion of said enclosure; and
(d) wherein said optical signal passes though at least a portion of the wall of said enclosure.
35. The system of claim 34 wherein said optical signal passes from outside said enclosure to within said enclosure.
36. The system of claim 34 wherein said transmitter is located outside said enclosure.
37. The system of claim 34 wherein said receiver is located within said enclosure.
38. The system of claim 34 wherein said first signal is less than approximately 24 volts.
39. The system of claim 34 wherein the voltage of said first signal is less than the voltage of said second signal.
40. The system of claim 39 wherein the voltage of said first signal is approximately 24 volts and said second signal is approximately 120 volts.
41. The system of claim 34 wherein said transmitter and said receiver are free from including a mechanical switching mechanism.
42. The system of claim 34 wherein the optical path of said optical signal is free from receiving additional light from a source other than said transmitter.
43. The system of claim 34 wherein said optical signal is infra-red.
44. The system of claim 34 wherein said optical signal is at least one of modulated, includes a carrier signal, has different frequencies, pulsed.
45. The system of claim 34 wherein said optical signal is provided to a plurality of said receivers.
46. The system of claim 45 wherein each of said receivers is associated with a different electrical device to which power is selectively provided.
47. The system of claim 46 wherein each of said receivers determines if said optical signal is intended for its associated electrical device.
48. The system of claim 34 wherein said receiver is electrically connected to said first device in a manner free from a wire between a connector of said receiver and a connector of said first device.
49. The system of claim 48 wherein said transmitter is located outside said enclosure.
50. The system of claim 48 wherein said receiver is located within said enclosure.
51. The system of claim 48 wherein said first signal is less than approximately 24 volts.
52. The system of claim 48 wherein the voltage of said first signal is less than the voltage of said second signal.
53. The system of claim 52 wherein the voltage of said first signal is approximately 24 volts and said second signal is approximately 120 volts.
54. The system of claim 48 wherein said transmitter and said receiver are free from including a mechanical switching mechanism.
55. The system of claim 48 wherein the optical path of said optical signal is free from receiving additional light from a source other than said transmitter.
56. The system of claim 48 wherein said optical signal is infra-red.
57. The system of claim 48 wherein said optical signal is at least one of modulated, includes a carrier signal, has different frequencies, pulsed.
58. The system of claim 48 wherein said optical signal is provided to a plurality of said receivers.
59. The system of claim 58 wherein each of said receivers is associated with a different electrical device to which power is selectively provided.
60. The system of claim 59 wherein each of said receivers determines if said optical signal is intended for its associated electrical device.
61. The system of claim 48 wherein said receiver includes a line conductor, a load conductor, and is free from including a neutral conductor.
62. The system of claim 48 wherein said transmitter is proximate said enclosure.
63. The system of claim 62 wherein said receiver is proximate said enclosure.
64. The system of claim 34 wherein said receiver includes a line conductor, a load conductor, and is free from including a neutral conductor.
65. The system of claim 34 wherein said transmitter is proximate said enclosure.
66. The system of claim 65 wherein said receiver is proximate said enclosure.
67. A system for controlling a remotely located electrical device comprising:
(a) a transmitter suitable to receive a first signal at a first voltage indicating the desired state of said electrical device and in response thereto provide an optical signal;
(b) an enclosure including a first device that selectively provides electrical power to said electrical device, wherein said electrical device is exterior to said enclosure;
(c) a receiver suitable to receive said optical signal and in response thereto selectively provide a second signal at a second voltage to said first device to provide said electrical power to said electrical device, wherein said electrical power is approximately 120 volts or more, wherein said transmitter and said receiver are maintained in a fixed relationship with respect to one another, wherein said transmitter is supported by said enclosure, wherein said receiver is located in said enclosure spaced apart from said transmitter by a portion of a wall of said enclosure; and
(d) wherein said optical signal electrically isolates said transmitter and said receiver.
68. The system of claim 67 wherein said optical signal passes from outside said enclosure to within said enclosure.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A magnetic head having a magnetoresistive film comprising an anti-ferromagnetic layer, a ferromagnetic -pinned layer, a non-magnetic intermediate layer, a soft magnetic free layer and an oxide layer of metal selected from Ta, Nb, Ti, Hf, W or an alloy thereof laminated in this order on a substrate.
2. A magnetic head as defined in claim 1, wherein the anti-ferromagnetic layer, the ferromagnetic pinned layer, the non-magnetic intermediate layer, and a non-magnetic and conductive film between the soft magnetic free layer and the oxide layer are laminated in this order on a substrate.
3. A magnetic head as defined in claim 1, wherein the thickness of the metal oxide layer is 1.0 nm or less.
4. A magnetic head as defined in claim 1, wherein the interlayer coupling field showing the magnitude of the ferromagnetic coupling between the ferromagnetic pinned layer and the soft magnetic free layer is substantially zero.
5. A magnetic head as defined in claim 2, wherein the thickness of the metal oxide layer is 1.0 nm or less.
6. A magnetic head as defined in claim 5, wherein the interlayer coupling field showing the magnitude of the ferromagnetic coupling between the ferromagnetic pinned layer and the soft magnetic free layer is substantially zero.
7. A magnetic head as defined in claim 4, wherein the thickness of the metal oxide layer is 1.0 nm or less.
8. A magnetic recording apparatus including a magnetic recording medium for recording information, a magnetic head having a magnetoresistive film comprising an anti-ferromagnetic layer, a ferromagnetic pinned layer, a non-magnetic intermediate layer, a soft magnetic free layer, a non-magnetic and conductive film, and an oxide layer of metal selected from Ta, Nb, Ti, Hf, W or an alloy thereof laminated in this order on a substrate, a head slider for holding the magnetic head, an actuator for guiding the head slider to a predetermined recording position of the recording position on the recording medium, a spindle motor rotating the recording medium and a signal processing system for processing information read out of the magnetic recording medium.