| 摘要 |
A hot restrike protection circuit provides complete shut down protection for a self-oscillating high intensity discharge lamp ballast of the type comprising a pair of complementary switching devices in a bridge configuration with a gate drive inductor in series with a second inductor, i.e., a control inductor, at the junction between the switching devices. The hot restrike protection circuit effectively comprises a three-terminal device for coupling across the control inductor. In particular, the HRP circuit comprises a sensing network for sensing voltage across the control inductor, a breakdown network for providing a breakdown path upon reaching a predetermined restrike voltage threshold across the control inductor, and a shutdown network for shutting down operation of the ballast until the lamp is sufficiently cool for restarting, thereby protecting ballast components during hot restrike, or re-ignition, of the lamp.
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