Protection circuit for electronic ballasts at fluorescent lamp life-end

摘要

An approach is proposed to detect and protect the electronic ballasts from abnormal operations when fluorescent lamps are coming to their life-ends. A protection circuit is designed to identify the abnormal operation by detecting the dc component on the lamp voltage. A design example is used to illustrate the operations of the protection method. Experimental results demonstrate that the detection and protection can function effectively under various fault conditions.