| 摘要 |
A lighting apparatus includes a full-wave rectifier circuit for rectifying an AC voltage from a commercial power source, a smoothing condenser connected is series with an inductor and a diode between output terminals of the full-wave rectifier circuit, a light source unit containing a series circuit of light emitting diodes and connected in parallel with the smoothing condenser, a MOSFET connected in series with the inductor between the output terminals of the full-wave rectifier circuit, and a control circuit for performing switching control of the MOSFET. In particular, the control circuit is constituted such that a voltage across the smoothing condenser is set higher than a peak of an input voltage input to the smoothing condenser through the diode and equal to a total sum of forward voltage drops of the light emitting diodes at a time of igniting the light source, under the switching control.
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