| 摘要 |
PURPOSE:To change load currents into constant by detecting load currents from a generating section for a power supply device using a piezoelectric ceramic transformer as a voltage value and controlling the intensity of oscillation of a driving section by a differential signal obtained by comparing load currents with reference voltage. CONSTITUTION:A diode D3 and a resistor R2 are connected to the electrode 19 side of a generating section 12 for a piezoelectric ceramic transformer 31, a resistor R3 and a capacitor C3 for smoothing are connected between electrodes 18, 19, and a resistor R4 detecting load currents is mounted. The voltage value of load currents detected by the resistor R4 is inputted to a differential amplifier 37, and compared with reference voltage, a differential signal between load currents and reference voltage is introduced to the resistance variable element 39 side, and outputs from a differential amplifier 33 and a power amplifier 17 are changed, thus controlling the intensity of oscillation of a driving section 11, then changing load currents into constant currents. |
