| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power supply unit using a piezoelectric transformer capable of obtaining voltage from high voltage of approx. 3kV to low voltage of some dozens, obtaining variable width for electric power of approx. a hundred times, and capable of improving efficiency. <P>SOLUTION: This power supply device 10 has the piezoelectric transformer 20 which transforms and supplies applied driving voltage Vd and supplies to a load L as output voltage Vo, an output detection portion 12 which detects the output voltage Vo of the piezoelectric transformer 20, a driving voltage control portion 14 which simultaneously controls frequency F and a duty ratio Du of the driving voltage Vd so that the output voltage Vo detected by the output detection portion 12, hereinafter referred to as "detected output voltage Vo", may become equal to the set output detection voltage Vs, hereinafter referred to as "set output voltage Vs", and a driving portion 16 which applies the driving voltage Vd to the piezoelectric transformer 20 by the frequency F and the duty ratio Du controlled by the driving voltage control portion 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
