| 摘要 |
PURPOSE:To generate a highly accurate constant voltage with a small sized device, by converting a high input voltage into a low output voltage at a switching circuit and driving the 2nd switching circuit converting the voltage into a low voltage of multioutput. CONSTITUTION:An AC input voltage AC is rectified D0 and smoothed C0, and applied to a switching TR and a pulse transformer 17 to obtain a high frequency voltage at secondary windings 11, 12. The output of the secondary windings is rectified D1, smoothed C1, amplified AMP1 and compared PWM1 with a triangle wave from an oscillator OSC1 to control the pulse width of the output of a transformer DT, allowing to keep an output voltage V1 constant. A voltage V2 with decreased regulation in interlocking with the voltage V1 drives a switching circuit consisting of a pulse transformer 18 and a switching TR19. The output of secondary wingings 13-16 of the pulse transformer 18 is rectified to apply voltages V3-V6 to each circuit, and the voltage V3 is amplified AMP2, the TR19 is controlled with an oscillator OSC2 and a comparator PWM2 to keep the voltage V3 constant. Thus, accurate constant voltage can be obtained with a small-sized device. |
