| 摘要 |
PURPOSE: To highly efficiently emit electroluminescence without producing noise by constituting a resonance circuit of an autotransformer and capacitive load. CONSTITUTION: A power source circuit is provided with a differential amplifier 11, a phase inverter 12, a push-pull drive circuit 13, an autotransformer 14, and a positive feedback circuit 15. Since the transformer 14 and an electroluminescent panel 16 constitute a parallel resonance circuit, the waveform of the AC voltage applied across the panel 16 becomes a sine wave and, accordingly, no much noise is produced and, at the same time, the luminous efficacy of the panel 16 is improved. The luminescence emitting luminance of the panel 16 is nearly fixed, because the frequency of the AC voltage becomes higher when the panel 16 is deteriorated and the capacity of the panel 16 becomes smaller. |
