Abstract: A switching type DC/DC converter wherein a switching control circuit is disposed at the primary winding thereof, and a detection signal, in a secondary winding, is insulated by a transformer and fed back to stabilize output voltages. Current consumption is reduced by using a transformer to act as an insulator, and the size of a stabilizing feedback circuit is reduced by using resistors and diodes so that the rate of production thereof is improved. A switching signal in a secondary winding of a main transformer is used as an excitation energy for an insulating transformer of the stabilizing feedback circuit, the excitation energy being supplied through an impedance device. The output voltage supplied to a load is supplied as a stabilizing signal to a primary winding of an insulating transformer by means of the stabilizing feedback circuit.