| 摘要 |
Apparatus for detecting certain load fault conditions of gaseous luminous tube loads connected to high voltage, high frequency power supplies including open-circuit, broken tube and other balanced load fault conditions. The detector includes a filter for emphasizing the harmonic content of the power supply output, an attenuator, a comparator or other detector/threshold device, and a delay circuit. A power supply shut-down switch may be included or the present fault detector may be interconnected to shut-down switch of a conventional ground fault interrupter. In one embodiment the filter and attenuator and, in another, the filter, attenuator, and delay circuit employ common components and may include a filter/attenuator capacitor defined by placement of metalization on the high frequency power supply transformer adjacent a high voltage output lead.
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