Asymmetrical ballast transformer

1. A system for coupling power to a plasma load, comprising:

an alternating current (AC) power source;

a ballast transformer having

a magnetic core,

a first primary winding on a primary side of the magnetic core and connected to the AC power source,

a secondary winding on a secondary side of the magnetic core, and

a second primary winding connected in series with the first primary winding and wound coaxial to the secondary winding on the secondary side of the magnetic core; and

a coaxial cable for connecting the secondary winding to the plasma load,

wherein the ballast transformer comprises a resonant transformer having a resonance associated with a) a capacitance of the coaxial cable connected to the secondary wining and b) a leakage inductance of the ballast transformer.

2. The system of claim 1 , wherein the ballast transformer comprises a step-up transformer or a step-down transformer.

3. The system of claim 2 , further comprising a plasma-generating region connected in series with the secondary winding via the coaxial cable.

4. The system of claim 3 , wherein the ballast transformer comprises a high Q circuit when no plasma exists in the plasma generating region and comprises a non-resonating, resistive circuit when a plasma exists in the plasma generating region.

5. The system of claim 4 , wherein a leakage inductance of the ballast transformer opposes current surges when the plasma is ignited in the plasma generating region.

6. The system of claim 5 , wherein the second primary winding is displaceable from the secondary winding to alter a coupling coefficient of the ballast transformer.

7. The system of claim 1 , wherein the plasma comprises an atmospheric pressure plasma.

8. The system of claim 1 , wherein the plasma comprises a non-thermal plasma used for the removal of organic contaminants, coatings, adhesives and sealants.

9. The system of claim 1 , wherein the second primary winding wraps around the secondary winding.

10. The system of claim 1 , wherein the second primary winding is offset axially from the secondary winding.

11. The system of claim 1 , wherein the second primary winding is displaceable from the secondary winding to alter a coupling coefficient of the transformer.

12. The system of claim 1 , further comprising respective bobbins for holding the first primary winding, the secondary winding, and the second primary windings in place around the magnetic core.

13. The system of claim 1 , wherein the respective bobbins have holes for air cooling.

14. The system of claim 1 , wherein annular gaps between bobbins supporting either the first primary winding, the second primary winding or the secondary winding provide cooling air.

15. The system of claim 1 , wherein at least one of the first primary winding and the secondary winding is disposed offset from the magnetic core.

16. The system of claim 11 , wherein the first primary winding is offset axially from the magnetic core.

17. The system of claim 1 , wherein the alternating current (AC) power source comprises a square wave inverter.

18. The system of claim 1 , further comprising a controller configured to at least one of:

control a gas flow through the plasma load, and

control an operational frequency of the AC power source.

19. The system of claim 18 , wherein the controller is configured to:

via the ballast transformer in claim 1 comprising an asymmetric ballast transformer having a sufficient leakage inductance to prevent current surges, control the AC power source such that a plasma is ignited and developed into a steady state atmospheric pressure plasma.

20. A method using any of the system statements above for providing power to a plasma, the method comprising:

providing power from an AC power source to a plasma load via the asymmetric ballast transformer in any of the statements above having a sufficient leakage inductance to prevent current surges; and

igniting and developing a steady state atmospheric pressure plasma.