| 摘要 |
<p>An emergency electronic ballast comprising a ballast circuit and an emergency device circuit is disclosed in the invention. The ballast circuit includes a rectifier bridge circuit, a power factor correction (PFC) circuit, a filtering capacitor, a driving circuit and a first inverting circuit. The emergency device circuit includes a control circuit, a charging circuit, a second inverting circuit and a switching circuit. The second inverting circuit boosts the voltage from a secondary battery to supply power, and the switching circuit selects one of the ballast circuit and the second inverting circuit to light a tube. A sampling circuit is arranged between the ballast circuit and the emergency device circuit, the sampling circuit samples the output information of the ballast circuit, and according to the received sampled signal and the condition of the mains supply, the control circuit controls the switching circuit to select one of the ballast circuit and the second inverting circuit. The integration of the emergency device and the electronic ballast in the invention ensures that the emergency device circuit is started only in the case of emergency, and the mutual interference between the ballast circuit and the emergency device circuit is avoided.</p> |
