| 摘要 |
PURPOSE: A microwave power lamp capable of reliable detection of burned out light bulbs is provided to reduce an interference by optical sources in detecting a defective electrodeless bulb. CONSTITUTION: A microwave powered lamp includes a light reflective cavity(28), an electrodeless bulb(26), a magnetron(12), a waveguide tube, a housing(22), a detector, and a magnetron controller(300). The electrodeless bulb is embedded in the light reflective cavity and emits a light when excited by microwaves. The magnetron provides microwaves for exciting the electrodeless bulb. The waveguide tube couples the microwaves emitted by the magnetron to the light reflective cavity to excite the electrodeless bulb. The housing contains the magnetron and the waveguide tube. The detector is disposed within the housing or the waveguide and detects the microwaves, not coupled to the bulb during operation of the magnetron, and outputs a signal indicative of a level of received microwaves. The magnetron controller causes the magnetron to be turned off when a level of the signal indicating the level of received microwaves exceeds a threshold value.
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