| 摘要 |
<p>Disclosed are a piezoelectric transformer drive circuit and drive method that are able to yield any output voltage more easily than dividing a clock signal in cases where a piezoelectric transformer is driven by a digital oscillator. An output sensor (3) detects the current flowing in a cold-cathode tube (2) and converts the same to a voltage signal. A controller (4) determines the setting (n) for a digital oscillator (5) and outputs the signal therefor based on the voltage signal detected by the output sensor (3). The digital oscillator (5) produces a time variant voltage of a specified frequency based on the setting (n) signal sent by the controller (4). A voltage approximately equal to the output voltage (V1') of the piezoelectric transformer (1) is generated as this time variant voltage by alternately generating frequency (F1) and frequency (F2), which are before and after the resonance frequency (F1') corresponding to the output voltage (V1').</p> |
