| 摘要 |
PURPOSE: An LED drive device for improving a power factor is provided to steadily run an LED by being fed back with the change of an LED output quantity and converting a switching frequency in a controlling unit. CONSTITUTION: A switching unit(400) switches a rectified power source according to an external control signal. A transformer(500) outputs the applied power source according to the switching of the switching unit to both ends. A combining unit(700) rectifies the currents of both ends which are outputted in the transformer and runs LED. A controlling unit(600) controls the switching unit so that the current provided to an LED unit is constant. The controlling unit is fed back with the output current of the LED unit and changes a switching frequency on a resonance curve.
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