| 摘要 |
PURPOSE:To obtain low frequency output by switching a piezoelectric transformer at lower frequency than the intrinsic resonant frequency. CONSTITUTION:The first oscillator 5 generates a signal (a) having equal intrinsic resonant frequency to piezoelectric porcelain, and the second oscillator 6 generates a low frequency signal (b). A switching circuit 7 produces a burst signal (c) from both the signals (a) and (b), and applies it through an amplifier 8 to a piezoelectric transformer 9. thus, the amplifier 9 is driven by the resonant frequency components of the signal (c) and produces a signal (d). The signal (d) contains low frequency high voltage signal having approximately sine wave components on the envelope in harmonic waves of the intrinsic resonant frequency. This is fed through a rectifying circuit 10 and a smoothing circuit 11 to the load 12, thereby obtaining the low frequency high voltage signal having smoothed waveform (f). Thus, low frequency high voltage can be obtained by utilizing piezoelectric transformer. |
