Controlling an electronic dimming ballast during low temperature or low mercury conditions

摘要

An electronic dimming ballast or light emitting diode (LED) driver for driving a gas discharge lamp or LED lamp may be operable to control the lamp to avoid flickering and flashing of the lamp during low temperature or low mercury conditions. Such a ballast or driver may include a control circuit that is operable to adjust the intensity of the lamp. Adjusting the intensity of the lamp may include decreasing the intensity of the lamp. The control circuit may be operable to stop adjustment of the intensity of the lamp if a magnitude of the lamp voltage across the lamp is greater than an upper threshold, and subsequently begin to adjust the intensity of the lamp when the lamp voltage across the lamp is less than a lower threshold. Subsequently beginning to adjust the intensity of the lamp may include subsequently decreasing the intensity of the lamp.

主权项

1. A method for controlling an amount of power delivered to an electrical load, the method comprising:
adjusting a first magnitude of a first operating characteristic of the electrical load; measuring a second magnitude of a second operating characteristic of the electrical load, the second operating characteristic different than the first operating characteristic; stopping adjustment of the first magnitude of the first operating characteristic of the electrical load if the second magnitude of the second operating characteristic crosses a first threshold; and subsequently beginning to adjust the first magnitude of the first operating characteristic of the electrical load when the second magnitude of the second operating characteristic crosses a second threshold.