GAPPED RESONANT CURRENT TRANSFORMER

Abstract

A gapped resonant current transformer that has a pre-determined gap in a split-core. The invention eliminates the need for a magnetic flux shunt between the primary and secondary windings. Further, the sensitivity to the clamping force holding the two halves of the split-core is reduced as well as temperature effects on the core. Finally, excess heat is removed from overload (saturation) by circulating power back into the line.

Claims

1. A resonant current transformer comprising: a toroid core cut into two substantially identical halves wherein said two halves are clamped together to form a pre-determined gapped split-core such that said pre-determined gapped split-core having an installation clamping force requirement wherein the sensitivity of the installation clamping force on the split-core on the power output is reduced and, wherein the effect of temperature on the core saturation point is also substantially reduced.

2. The resonant current transformer of claim 1 wherein said pre-determined gap of the split-core is filled with a nonmagnetic material.

3. The resonant current transformer of claim 2 wherein said nonmagnetic material placed within said gap is parylene.

4. The resonant current transformer of claim 2 wherein said nonmagnetic material placed within said gap is paint.

5. The resonant current transformer of claim 2 wherein said nonmagnetic material placed within said gap is tape.

6. The resonant current transformer of claim 2 wherein said nonmagnetic material placed within said gap protects the core interfaces from environmental corrosion.

7. The resonant current transformer of claim 2 further comprising a bus wire conducting a line current through said core causing a magnetic flux to be generated therein.

8. The resonant current transformer of claim 7 further comprising a first winding to said core that enables said magnetic flux to provide a voltage to a load.

9. The resonant current transformer of claim 8 further comprising a second winding on said core wherein said second winding has a capacitor to provide a resonate circuit at the line frequency.

10. The resonant current transformer of claim 9 further comprising at least one tap on said second winding permitting the best match between line frequency and the resonate circuit to provide the maximum output power.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG. 1 is an illustration of the prior art.

[0016] FIG. 2 is an illustration of resonant current transformer having a gapped split-core in accordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0017] Now referring to FIG. 1, this is an illustration of the prior art having a current transformer with a winding used to supply a small amount of power to a load. Toroid core 1 is cut into two halves 1 & 2 forming interfaces 4's. Bus wire 7 conducting line current 5 causes a magnetic flux to be generated in the core. Load winding 3 coupled to this magnetic flux provides voltage to output load 6.

[0018] As shown in FIG. 2, there is an illustration of the present invention. This invention uses toroid core 1 cut in two halves where a nonmagnetic material 11 (such as parylene, paint, tape, etc.) of known thickness is placed in the two gaps to protect the core interfaces from environmental corrosion. Bus wire 7 conducting line current 5 causing a magnetic flux to be generated in the core. Winding 3 coupled to this magnetic flux provides voltage to load 6. Added to this core and coupled to the magnetic flux is an auxiliary winding 10 of higher turn count. This winding is connected to a capacitor 9 to form a circuit resonate at the line frequency. FIG. 2 also shows taps 8 which allow selection during manufacturing of the best match between the line frequency and the circuit self-resonant frequency. This optimum match improves the maximum output power over the prior art.

[0019] High voltage spikes may be destructive to the output load with a prior art device. Voltage slow rate of change across the invention capacitor 9 of FIG. 2 suppresses the voltage spikes or peeks.

[0020] Although the present invention has been described with reference to certain preferred embodiments thereof, other versions are readily apparent to those of ordinary skill in the preferred embodiments contained herein.