Abstract: The invention relates to a multi-layer planar inductance coil on a portion of a first plate-shaped support (10) which has a plurality of first conducting layers (14) which extend substantially parallel to each other and which is designed for holding and contacting further electronic components (32), wherein at least one conducting layer (14) of the first support, which forms a first electrical winding, is arranged for co-operation with a core (24) which is provided for guiding a magnetic flux and which is to be arranged in the portion, wherein at least one second plate-shaped support (20; 22; 44; 54) with a plurality of second conducting layers (16; 18) which extend substantially parallel to each other is so arranged in the portion parallel to the first support (10) that at least one conducting layer (16) of the second support, which provides a second electrical winding, can inductively co-operate with the core (24) and the first electrical winding.

Abstract: With direct current/direct current converters of modern construction, which can be operated at frequencies as high as 500 kHz, the number of secondary windings that are necessary decreases with simultaneously high currents, so the necessary voltage can be generated by a single winding, or even by less than one winding. A push-pull converter exhibits, for example, a transformer with a center limb (19) and two outer limbs, and that contains on the secondary side two coils (29, 30), each of which consists of a single, complete winding with one center tap (B, E) each. These coils are placed around the center limb (19) in such a way that the two center taps (B, E) come to be located opposite each other in two openings (18) between the outer limbs.

Abstract: In a synchronous rectifier having at least a transformer whose flow of current through the primary winding is periodically switched on and off and includes, as a controlled rectifier, a first and second MOSFET. A third and fourth MOSFET are provided whose source terminals are connected to the gate terminals of the first and second MOSFETs and to a second of two output terminals of the rectifier through a resistor. A Schottky diode is connected in parallel with the drain and source terminals of the first MOSFET with the cathode of the Schottky diode and the drain terminal of the first MOSFET being connected to a first of the two output terminals. A switching block circuit is connected between the parallel connection of the Schottky diode and the first MOSFET and the second output terminal of the rectifier. A capacitor is connected between the gate terminals of the third and fourth MOSFETs and the second output terminal of the rectifier. The output of a logic unit is connected in parallel with the capacitor.

Abstract: A switching amplifier including a plurality of switching stages, each having a drive transformer, the primary winding of which is separated from the secondary winding in a manner such that no conductive connection exists between them. The primary windings of each drive transformer is connected by means of controllable switching elements to a supply-voltage source in a push-pull circuit arrangement. The switching elements are controlled by means of a signal converter which converts an analog input signal into at least one pulse sequence which is applied to the control electrodes of the controllable switching elements by means of at least one control transformer having at least one primary winding coupled to the pulse sequence and plural secondary windings coupled to the control electrode of a respective switching element. The output terminals of the secondary winding of the drive transformer are connected to a full-wave rectifier.

Abstract: A method of amplifying an analog low-frequency signal, and a switching amplifier implementing the method, wherein the maximum amplifiable voltage of the analog input signal is divided up into as many voltage bands as there are switching stages provided in the switching amplifier, and one switching stage is associated with each voltage band. Thereby the number of switching stages actuated and their switched-on period may be modulated in dependence upon the amplitude. In this way it is possible to reduce considerably the total number of switching processes during one period of the low-frequency input signal and the losses connected with each switching process.

Abstract: A compact and inexpensive LF power amplifier is disclosed. A plurality of pulse trains which are phase shifted relative to each other are width-modulated by an input LF signal. The modulated pulse trains are individually amplified, preferably by means of a plurality of respective power transformers and switch elements. The switch elements include any suitable combination of electron tubes and semiconductor switches. The keying ratio of the amplifier is improved by associating the pulse trains in pairs, the two members of each pair being phase shifted 180.degree. relative to each other. The amplified pulse trains are superimposed to form a single combined amplified pulse train.