| 摘要 |
A ballast comprises an inverter having a transformer comprising a core, a primary winding, and a secondary winding for connecting to a lamp and providing voltage thereto. The ballast includes a fault condition detection circuit connected to the inverter for disabling the inverter to discontinue energization of the lamp when a fault condition occurs. The fault condition detection circuit comprises an other primary winding wound on the core of the transformer for receiving a voltage signal proportional to a voltage across the secondary winding, a voltage blocking circuit connected to the other primary winding for receiving the voltage signal from the other primary winding, and a capacitor connected between the voltage blocking circuit and ground potential. The voltage blocking circuit is configured to selectively conduct and block the received voltage signal as a function of the frequency of the received voltage signal. |
