| 摘要 |
A fluorescent illuminating apparatus includes an inductive-resistive structure that induces fluorescence in a fluorescent lamp when an electric current is passed through the inductive-resistive structure while an electric potential is applied across the fluorescent lamp A source of rippled/pulsed direct current is responsive to a control sub-circuit, which outputs a lamp voltage signal representative of the electric potential to be applied to the fluorescent lamp. A power supply sub-circuit is responsive to the control sub-circuit and imposes the electric potential at the value indicated by the lamp voltage signal. A method of inducing fluorescence includes passing a current through an inductive structure adjacent to a fluorescent lamp. An alternating current drive circuit for illuminating the fluorescent lamp includes a source of rippled/pulsed DC voltage, a polarity-reversing circuit and a controller connected to the polarity-reversing circuit, which periodically generates a signal to reverse the polarity of the voltage applied to the lamp. The electric potential applied to the fluorescent lamp is delayed for a first time period until the fluorescent lamp heats to a first temperature. The electric potential is then applied to the fluorescent lamp at a first level, and delays to allow the value of the rippled/pulsed direct current to stabilize. The direct current is then measured, and the electric potential is applied to the fluorescent lamp at a second level. The value of the dimming voltage is measured, and the electric potential applied to the lamp is adjusted accordingly by varying its duty cycle.
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