<p>Disclosed a switching power supply for controlling an output voltage to a constant value with respect to fluctuations in input or in load. The switching power supply incorporates a DC power supply; two dividing capacitors connected in series to both ends of the DC power supply; two semiconductor switches connected in series to both ends of the DC power supply; a transformer having a primary winding one end of which is connected to a connecting point of the two dividing capacitors; and a T type circuit composed of two inductors connected in series between a connecting point of the two semiconductor switches and the other end of the primary winding of the transformer and a capacitor connected between a connecting point of the two inductors and the other end of the primary winding of the transformer. Control characteristics of the switching power supply are improved by reducing dependency of the output voltage on the fluctuations in load.</p>
