| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply device which enables reduction in switching noise, and specifically, a power supply device which enables the reduction of switching noise, even when the output of a miniature bulb is controlled in an audio-frequency band. SOLUTION: A power supply device comprises an AC power supply 1, a load (in this case, a discharge lamp) 5, a 2nd rectifier which is connected between both terminals of the AC power supply 1 and rectifies the AC power supply 1, a power supply circuit 4 which converts a DC voltage V1 outputted by the 2nd rectifier into a high-frequency voltage and supplies it to the discharge lamp 5, a 1st rectifier which is composed of diodes D5 and D6 and connected between both the terminals of the AC power supply 1, a power supply circuit which supplies a DC voltage outputted by the 1st rectifier to a miniature bulb 3 by the switching operation of the switching device Q1, and a noise-proof common filter 2 connected between the AC power supply 1 and the 1st rectifier. |
