摘要 |
<p>An inverter power source apparatus using a piezoelectric transformer, has : variable oscillating device for oscillating a pulse signal; pulse-width changing device for changing a width of said pulse signal of said variable oscillating device; driving device for generating a driving signal on the basis of an output of said pulse-width changing device; a piezoelectric transformer which is driven by said driving signal, drives a predetermined load, and has input and output electrodes; detecting device for detecting a relationship between said driving signal and a resonance frequency of said piezoelectric transformer, and for, on the basis of a result of the detection, controlling a frequency of said oscillation signal of said variable oscillating device so that a difference between said resonance frequency and a frequency of said driving signal is substantially within a preset range; and pulse-width controlling device for, when a detection results of said detecting device shows that said difference between said resonance frequency and said frequency of said driving signal is substantially within said preset range, controlling said pulse-width changing device so that a current flowing through said load is substantially constant. <IMAGE></p> |