摘要 |
A ballast circuit (100) includes a ground fault detector (200). The ballast circuit is arranged for coupling to a power source (101) and a load (135, 137), the power source characterized by a source frequency, the ballast circuit including an electromagnetic interference ("EMI") filter (110) which includes a ground terminal (145). The ground fault detector (200) determines when the load is coupled to a ground fault (141) by detecting the presence of a high-frequency current at the ground terminal, the high-frequency current characterized by a frequency that is substantially greater than the source frequency. When the high-frequency current is detected, the ground fault detector provides an output signal (150) which may be used to disconnect the load from the ballast circuit.
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