| 摘要 |
A ballast (20) for powering a gas discharge lamp (70) comprises an inverter (200) and an arc protection circuit (600). Arc protection circuit (600) monitors an electrical signal within the ballast. In response to occurrence of a disturbance in the signal, such as what occurs during output arcing, arc protection circuit (600) disables the inverter (200) for a timed shutdown period. Arc protection circuit (600) provides a timed starting period for igniting t he lamp, during which time any disturbance in the electrical signal is essentially ignored and inverter (200) is allowed to continue to operate. Arc protection circuit (600) also provides a restart function for periodically attempting t o ignite and operate the lamp. Arc protection circuit (600) is preferably realized using a timer integrated circuit (U1) with associated discrete circuitry, and may be adapted for use with ballasts having self oscillating or driven type inverters.
|
