| 摘要 |
PURPOSE:To enable the plus and minus power supplies to supply equal power to the load, in the power supply unit supplying power to the amplifying circuit of pulse width modulated signal of two power supply system. CONSTITUTION:The transistors Tr11a, 11b are alternately ON and OFF. Further, since the winding ratio of the primary winding 12a and the secondary winding 12b of the transformer 12 is 1:1, then the positive voltage of the smoothing capacitor 9a for positive DC voltage is fed to the primary winding 12a when Tr11a is ON and Tr11b is OFF, equal negative voltage is produced to the secondary winding 12b, and the negative voltage of the smoothing capacitor 9b for negative DC voltage is fed to the primary winding 12a when Tr11b is ON and Tr11a is OFF, and equal positive voltage is produced to the secondary winding 12b. Further, since this is repeated sequentially, when either of positive or negative potential of the smoothing capacitors 9a,9b is increased than another potential, current flows from the higher potential to lower side through the transformer 12 to keep equal the potential of each capacitor. |
