Electrical switch and circuit breaker

1. An electrical switch comprising:

a graded resistance block comprising a first end having a first electrical resistivity and a second end having an electrical resistivity greater than the first electrical resistivity;

a fixed contact electrically coupled to the first end of the graded resistance block;

a sliding contact configured to slide over the graded resistance block; and

a forcing, mechanism configured to slide the sliding contact over the graded resistance block from the first end to the second end;

wherein the graded resistance block further comprises an arc shaped sliding surface, and the forcing mechanism comprises a rotary assembly configured to slide the sliding contact along the arc shaped sliding surface.

2. The electrical switch of claim 1 , wherein electrical resistivity of the graded resistance block varies by up to 12 orders of magnitude between the first end and the second end.

3. The electrical switch of claim 1 wherein electrical resistivity of the graded resistance block varies from 1-10 micro Ohm meter at the first end to 1-10 Ohm meter at the second end.

4. The electrical switch of claim 1 , wherein the graded resistance block comprises a plurality of resistance cassettes disposed end to end, wherein each of the plurality of resistance cassettes have a distinct electrical resistivity.

5. The electrical switch of claim 1 , wherein the graded resistance block comprises a ceramic monolithic cassette comprising aluminum oxide, zinc oxide, barium titanate, silver, molybdenum or combinations thereof.

6. The electrical switch of claim 1 , wherein the graded resistance block comprises a conjugated polymer cassette.

7. The electrical switch of claim 1 , wherein:

the graded resistance block comprises a planar sliding surface; and

the forcing mechanism comprises a translating assembly, to slide the sliding contact along the planar surface.

8. The electrical switch of claim 1 further comprising:

a spring, assembly mechanically coupled to the graded resistance block to exert a normal contact force against the sliding contact.

9. The electrical switch of claim 1 further comprising:

a spring assembly mechanically coupled to the sliding contact to exert a normal contact force against the graded resistance block.

10. An electrical switch comprising:

a first contact;

a graded resistance block slidably coupled to the first contact and comprising a first end having a first electrical resistivity and a second end having an electrical resistivity greater than the first electrical resistivity;

a second contact electrically coupled to the first end of the graded resistance block;

a forcing mechanism to slide the graded resistance block across the first contact such that a current path between the first and second contacts transitions from a conducting state to a non-conducting state.

11. The electrical switch of claim 10 , wherein electrical resistivity of the graded resistance block varies by up to 12 orders of magnitude between the first end and the second end.

12. The electrical switch of claim 10 , wherein electrical resistivity of the graded resistance block, varies from 1-10 micro Ohm meter at the first end to 1-10 Ohm meter at the second end.

13. The electrical switch of claim 10 , wherein the graded resistance block comprises a plurality of resistance cassettes disposed end to end, wherein each of the plurality of resistance cassettes have a distinct electrical resistivity.

14. The electrical switch of claim 10 , wherein the graded resistance block comprises a ceramic monolithic cassette comprising aluminum oxide, zinc oxide, barium titanate, silver, molybdenum or combinations thereof.

15. The electrical switch of claim 10 , wherein the graded resistance block comprises a conjugated polymer cassette.

16. The electrical switch of claim 10 , wherein:

the graded resistance block comprises an arc shaped sliding surface; and

the forcing mechanism comprises a rotary assembly configured to slide the arc shaped sliding surface over the first contact.

17. The electrical switch of claim 10 , wherein:

the graded resistance block comprises a planar sliding surface; and

the forcing mechanism comprises a translating assembly to slide the planar surface over the first contact.

18. The electrical switch of claim 10 further comprising:

a spring assembly mechanically coupled to the graded resistance block to exert a normal contact force against the first contact.

19. The electrical switch of claim 10 further comprising:

a spring assembly mechanically coupled to the first contact to exert a normal contact force against the graded resistance block.

20. An electrical switch comprising:

a graded resistance block comprising a first end having a first electrical resistivity and a second end having an electrical resistivity greater than the first electrical resistivity;

a first sliding contact configured to slide over the graded resistance block; and

a second sliding contact configured to slide over the graded resistance block, wherein the first sliding contact and the second sliding contact are configured to contact the graded resistance block at a predetermined separation measured in a direction of motion of the first sliding contact and the second sliding contact.

21. The electrical switch of claim 20 , wherein the predetermined separation is a fixed separation.

22. The electrical switch of claim 20 , wherein the predetermined separation is a continuously varying separation.

23. The electrical switch of claim 20 , wherein the graded resistance block comprises a ceramic monolithic cassette comprising aluminum oxide, zinc oxide, barium titanate, silver, molybdenum or combinations thereof.

24. The electrical switch of claim 20 , wherein the graded resistance block comprises a conjugated polymer cassette.