| 摘要 |
PURPOSE:To permit feedback of a voltage analogical to an output voltage thereby increasing stability by a method wherein harmonics component of a feedback signal is suppressed through a low-pass filter connected to the third winding of the transformer which is used for obtaining at feedback signal to be fed to a switching circuit. CONSTITUTION:A DC power supply 13 is connected to a switching circuit 14 and its output is given to a transformer 20 having the primary winding 20a, the secondary winding 20b and the third winding 20c. DC power from the secondary winding 20b is fed to a load 23. The third winding 20c is closely coupled to the primary winding 20a, thereby its output being fedback to the switching circuit 14 via a low- pass filter 26. Thus the feedback voltage input to a detector 17 is of sinusoidal wave-form without harmonics component, being analogical to the wave-form of a voltage generated in the secondary winding 20b. Therefore the output voltage stability can be ensured in correspondence to the voltage generated in the secondary winding 20b. |
