| 摘要 |
PURPOSE:To reduce the size and to simplify the construction of a switching power source circuit by providing a magnetic flux controller at the secondary side of an insulating converter transformer. CONSTITUTION:A switching power source circuit has a converter 1, a DC main power source 2, an insulating converter transformer PIT and a magnetic flux controller 11, drives the switching transistor Q1 of the converter 1 by a self- exited oscillator to obtain the first - third voltage outputs E01-EAF from the secondary windings N12-N14 of the transformer PIT. In this case, the secondary winding N34 of a magnetic flux controlling saturable transformer PRT which forms the controller 11 is connected only with the secondary winding N12 side of the transformer PIT to control the current Ic of the primary winding N33 by an error signal generator 12. Thus, when the current IL of the output line is varied by the input voltage of load variation, the current Ic of the primary winding N33 is controlled by the generator 12 to stably control the value of the output voltage E01 at the prescribed value. |
