Power delivery system for providing power to sensor head of paper machine or other system

1. An apparatus comprising:

a chassis configured to move back and forth along multiple rails;

rail contacts configured to touch the rails, wherein each rail contact comprises an outer race and an inner race;

electrical contacts configured to touch the rail contacts to form electrical connections to the rails and receive power from the rails via the rail contacts;

a power converter/conditioner configured to receive the power from the rails via the electrical contacts and to at least one of: convert the power into a different form and condition the power; and

one or more sensors configured to measure at least one characteristic of a material, the one or more sensors configured to operate using the power from the power converter/conditioner.

2. The apparatus of claim 1 , wherein the electrical contacts touch one of the inner races and the outer races of the rail contacts to receive the power from the rails.

3. The apparatus of claim 1 , wherein:

the outer race of each rail contact is configured to contact (i) one of the rails and (ii) one of the electrical contacts; and

bearings located between the outer and inner races of each rail contact are insulative.

4. The apparatus of claim 1 , wherein:

the outer race of each rail contact is configured to contact one of the rails; and

the inner race of each rail contact is configured to contact one of the electrical contacts.

5. The apparatus of claim 1 , wherein each rail contact further comprises a connector fixedly connecting the outer and inner races of that rail contact.

6. The apparatus of claim 5 , wherein each rail contact is configured to pass electrical current through the outer race and the connector of that rail contact.

7. The apparatus of claim 1 , wherein the electrical contacts are configured to touch the rail contacts to form the electrical connections such that current paths between the rails and the electrical contacts pass through at least the outer races of the rail contacts.

8. The apparatus of claim 1 , further comprising:

a wireless transceiver configured to wirelessly transmit sensor measurements from the one or more sensors.

9. The apparatus of claim 1 , further comprising:

a motor configured to move the chassis back and forth along the rails; and

a motor controller configured to control the motor.

10. The apparatus of claim 1 , wherein the chassis is configured to move back and forth on the rails.

11. The apparatus of claim 1 , wherein:

the chassis is configured to move back and forth on the rails; and

the electrical contacts are located on or in the chassis.

12. A system comprising:

a power supply configured to provide power over multiple rails; and

a sensor head comprising:

a chassis configured to move back and forth along the rails;

rail contacts configured to touch the rails, wherein each rail contact comprises an outer race and an inner race;

electrical contacts configured to touch the rail contacts to form electrical connections to the rails and receive power from the rails via the rail contacts;

a power converter/conditioner configured to receive the power from the rails via the electrical contacts and to at least one of: convert the power into a different form and condition the power; and

one or more sensors configured to measure at least one characteristic of a material, the one or more sensors configured to operate using the power from the power converter/conditioner.

13. The system of claim 12 , wherein:

the power supply is configured to provide the power over multiple sets of rails; and

the system includes multiple sensor heads configured to receive the power via different sets of rails.

14. The system of claim 13 , wherein the sensor heads are configured to measure the at least one characteristic of a web of the material on opposite sides of the web.

15. The system of claim 12 , wherein:

the outer race of each rail contact is configured to contact (i) one of the rails and (ii) one of the electrical contacts; and

bearings located between the outer and inner races of each rail contact are insulative.

16. The system of claim 12 , wherein:

the outer race of each rail contact is configured to contact one of the rails; and

the inner race of each rail contact is configured to contact one of the electrical contacts.

17. The system of claim 12 , wherein each rail contact further comprises a connector fixedly connecting the outer and inner races of that rail contact.

18. The system of claim 17 , wherein at least one of the connector and the inner race of each rail contact is insulative.

19. The system of claim 12 , wherein the sensor head further comprises a wireless transceiver configured to wirelessly transmit sensor measurements from the one or more sensors.

20. A method comprising:

moving a sensor head back and forth along multiple rails;

forming electrical connections to the rails at the sensor head using rail contacts that touch the rails and electrical contacts that touch the rail contacts;

receiving power from the rails via the electrical connections and at least one of: converting the power into a different form and conditioning the power; and

measuring at least one characteristic of a material using one or more sensors of the sensor head, the one or more sensors using the converted/conditioned power;

wherein the electrical contacts receive the power from the rails via the rail contacts; and

wherein each rail contact comprises an outer race and an inner race.

21. The method of claim 20 , wherein current paths between the rails and the electrical contacts pass through at least the outer races of the rail contacts.