Switching power supply for generating a load voltage (U L) from the difference between a first and a second output voltage (Out1, Out2), wherein the switching power supply can be connected to an input DC voltage source which provides an input DC voltage (U B), and wherein the switching power supply comprises the following components: - a transducer (Tr), having a first winding, which is connected in series to a first clocked switch means, and having a second winding, which is connected in series to a second clocked switch means, - a first output capacitor which is connected to the first winding and from which the first output voltage can be tapped off, - a second output capacitor which is connected to the second winding and from which the second output voltage can be tapped off, - a control circuit (St) which is connected to the first and second clocked switch means (T1, T2), characterized in that the control circuit (St) is implemented such that either, - in order to increase the load voltage (U L), during a switch on phase of the first clocked switch means, energy from the first output capacitor and from the input DC voltage source can be stored in the transducer (Tr) and, during a switch off phase, the stored energy can be transferred to the second output capacitor, or - in order to reduce the load voltage (U L), during a switch on phase of the second clocked switch means, energy from the second output capacitor and from the input DC voltage source can be stored in the transducer (Tr) and, during a switch off phase, the stored energy can be transferred to the first output capacitor, and whereby the switching power supply further comprises - a first input rectifying element, connected in the forward direction with respect to the input DC voltage source (U B), which is connected to the first winding, and - a second input rectifying element, connected in the forward direction with respect to the input DC voltage (U B), which is connected to the second winding. - a transducer (Tr), having a first winding, which is connected in series to a first clocked switch means, and having a second winding, which is connected in series to a second clocked switch means, - a first output capacitor which is connected to the first winding and from which the first output voltage can be tapped off, - a second output capacitor which is connected to the second winding and from which the second output voltage can be tapped off, - a control circuit (St) which is connected to the first and second clocked switch means (T1, T2), - in order to increase the load voltage (U L), during a switch on phase of the first clocked switch means, energy from the first output capacitor and from the input DC voltage source can be stored in the transducer (Tr) and, during a switch off phase, the stored energy can be transferred to the second output capacitor, or - in order to reduce the load voltage (U L), during a switch on phase of the second clocked switch means, energy from the second output capacitor and from the input DC voltage source can be stored in the transducer (Tr) and, during a switch off phase, the stored energy can be transferred to the first output capacitor, and whereby the switching power supply further comprises - a first input rectifying element, connected in the forward direction with respect to the input DC voltage source (U B), which is connected to the first winding, and - a second input rectifying element, connected in the forward direction with respect to the input DC voltage (U B), which is connected to the second winding.