| 摘要 |
PROBLEM TO BE SOLVED: To provide a voltage sufficient for lighting a fluorescent lamp by stepping up pulse-like voltages generated by resonance. SOLUTION: Since a fluorescent lamp 2 is not lit up when a power source is turned on, an inverter output is open and a Q of a series oscillation circuit is high. Therefore, a peak voltage of a pulse-like waveform exceeds a starting voltage of the lamp 2 and is applied between electrodes 2a and 2b. Impedance of an inverter load decreases, the Q of the oscillation circuit decreases, and the inverter output decreases to be lower than that before starting. Here, since the peak voltage is higher than a discharge sustaining voltage, the lamp 2 is lit up by discharging. As a result, the energy stored in a step-up transformer 11 is almost completely consumed, and the voltage produced by resonance is lower than the initial value, the voltage applied to the lamp 2 does not reach the discharge sustaining voltage and therefore has nothing to do with the lighting of the lamp 2. |
