CS242153B1 - Interference suppression in pulse converters - Google Patents

Abstract

The solution relates to the field of electrical engineering and solves the connection for suppressing interference in pulse converters, in which a wide range of interference signals arise as a result of the switching mode of operation. The essence of the solution is that it consists of a switching element connected between the axes of the divided primary winding of a power transformer, while mutually connected shielding foils are placed between the secondary winding and the sections of the primary winding. Furthermore, the switching element and the power transformer are covered with a common shielding cover connected by an auxiliary capacitor to the electrodes of the switching element. The connection can be used in all devices operating in the pulse switching mode, in which it is possible to connect the switching element between two sections of a suitable divided load.

Description

242133

BACKGROUND OF THE INVENTION The invention relates to a circuit for suppressing impulsive transducers in which a wide range of high amplitude interfering signals is generated as a result of the switching mode of operation, and which are transmitted to other circuits even by relatively small capacitances. At present, the problem of suppressing the interference of impulsive transducers is solved by a suitable spatial distribution of the individual components of the transducer. It is being used to suppress the leakage of the disturbing power supply and the mains supply! input and output symmetric and unsymmetrical filters and screening foils between power transformer windings. Suppressing the interfering radiation of the pulse converter itself is achieved by consistent shielding using an earthing or neutral conductor. The disadvantages of these couplings are time-consuming experiments to obtain the optimum distribution of the pulse converter components, the weighting, the weight and the price due to the use of large filters, the need to use a ground or neutral conductor, and due to the large grounding the higher risk of magnetically inducing disturbing signals. Neither of these methods involves the possibility of reducing the amplitude of the source of the interfering signal.

The aforementioned drawbacks are eliminated by the interference suppression device in impulsive transducers consisting of a sensing element and a power transformer of the safety of the use of a grounding or zeroing conductor according to the invention, the principle of which is that the switching element is connected between two axially divided primary voltages. nutia. the power transformer, advantageously, the layers of the individual primary winding sections connected to the power supply are positioned so as to be spatially connected to the secondary winding, disposed between the individual primary windings. Furthermore, it is possible to use interconnecting screening foils located between the secondary winding and the primary winding sections, wherein the screening films are also conductively connected to the core of the power transformer and this connection is also a conductor or via a condenser connected to the ground or nu-lovacietnu drivers ,. Furthermore, the switching element and the power transformer are covered by a shielding shield, which is also an auxiliary capacitor connected to the electrodeposition element, the common shielding being also the driver or via a condenser connected galvanically to the grounding conductor. Advantages of engaging the interference suppressor 11a are that the source of the interference jamming source is subdivided with the opposite polarity and the amplitude of the jamming signal. Furthermore, the jamming signals are compensated for in the shielding foils not in the secondary transformer winding. Furthermore, it is achieved that the parasitic capacities between the shielding cap and the secondary circuits of the encoder, possibly with any external independent circuits, flow at least and with zero currents induced by the suppressing signal, without the need for a thorough grounding of the shielding cover and the use of complex and bulky ones. filtering circuits.

The accompanying drawings show examples of circuitry connections for suppressing the inventive circuitry. Fig. 1 shows the connection with the primary winding divided by the supply sections. FIG. 2 illustrates a preferred embodiment of the power transformer winding winding. FIG. 3 shows a connection using shielding films between the secondary winding and the primary winding sections and sections. Fig. 4 shows a connection with the use of a common shadow cover.

The connections in Figures 1, 2, 3, 4 consist of a switching element 4 connected to the primary winding intermediate section 7 of the power transformer 3 and to the core 6 and to the secondary winding 8, with the supply terminals 1 shown, which are connected to the primary winding sections 7 The primary capacitances 10 and the secondary capacitances 9 between the primary winding sections 7, the secondary winding 8 and the core 6 of the power transformer 5 are also indicated here.

Figures 1 and 2 show still bonding capacities 11 between the primary winding sections 7 and the secondary winding 8. In Fig. 3, shielding foils 12 are arranged, located between the secondary winding 8a and the primary winding sections 7, together with a representation of the primary windings 8a. the foil capacities 13 and the secondary foil capacities 14 of the shading foils 12 relative to the primary winding sections 7 and the secondary winding 8. At the same time, the connection of the shielding foils 12 to the conductor 15 or the condenser 18 to the earth or neutral conductor 3 is illustrated.

FIG. 4 illustrates a common shielding 20 showing electrode capacitances 19 of the capacitance 18, a transformer capacity 21 representing the power transformer substitute capacitance 5 relative to the common shielding housing 20 from the secondary circuitry 22 and the external circuitry 23. through the condenser 16 with the earth or neutral conductor.

With this construction in Fig. 1, the primary capacitances 10, secondary capacitance 9, of the interconnecting capacities 11 are obtained in a balanced manner in such a way that the interfering signals of opposite polarity occurring on the electrodes of the switching element 4 due to the switching mode they transmit to the secondary winding 8 with the same level and compensate for each other. 2, when the layers of the primary winding sections 7 connected to the electrode outlets 2 are located at the highest distances from the secondary winding 8, in the case of the lowest bonding capacity, further reducing the ambit of the interfering signals transmitted to the secondary winding 8.

By using the shielding films 12 in FIG. 3, the interference signals transmitted through the primary film capacities 13 and the primary capacities 10 are compensated for each other and the core of the shielding films 12 to be transmitted and the secondary capacities 9 and the secondary film capacities 14 are not transmitted to secondary winding 8 no interfering signals. In the case of a higher effect, it is possible to shorten the residual signals in the shielding foils 12 via a conductor 15 or via a condenser 16 with an earthing or neutral conductor 3. Switching element 4, power transformer 5 and other circuits electrically connected to the electrodes 4 is suitable for positioning in a common shield 20 in Fig. 4. A suitable space arrangement is a balanced system of electrode capacities 19, transformer capacity 21, capacitance 18, with auxiliary capacitor 17 in such a way that the parasitic capacitance 24, no interfering signal is transmitted to the secondary openings 22 or to any external circuits 23. To suppress residual signal residues in the common shielding cover 20, it may be shorted to conductor 15 or via capacitor 16 to ground or reset. driver 3.

By connecting the switching element 4 between the doors of a suitable split primary vortex 7, the source of the interfering signal is divided into two sources with half-amplitude of the interference signal with mutually polarity, FIGS. 2 and 3. It can be achieved that the interference voltage transmitted through the pa the resistive coupling capacities on the secondary output of the power transformer 5 are compensated in full or in part, it being preferable to locate the winding layers connected to the electrodes of the switching element 4, that is, the maximum amplitude of the interfering signal into the space with the smallest binder capacitance to the secondary j side of the power transformer 5, thereby making the interfering signals needed on the secondary side compensate are minimal amplitudes. It is possible to insert shielding films 12 connected to each other between the secondary winding 8 and the primary winding sections 7, whereby the interfering signals are compensated with the already embossed films 12 and not with the secondary winding of the power transformer 5.

In order to remove the remaining uncompensated signal in the shielding foils 12, these can be shorted by a conductor 15, via a capacitor 16 with an earth or reset conductor 3. To suppress interference caused by unsymmetrical radiation of the electrode surfaces of the switching element 4, the winding of the power transformer 5, or other circuits galvanically connected to the electrodes of the switching element 4, serves the electromagnetic shielding by a common shielding capsule 20, in which a suitable structure of the bonding capacities of the common shielding cap 20 is formed by a suitable design distribution, eventually by a condenser 17 against the switching element electrodes 4, the power transformer 5 with another circuit galvanically connected to the electrodes of the switching element 4 together with the capacitance of the auxiliary condenser 17. This shade can be a conductor 15 or via a capacitor 1S connected to the grounding conductor wires 3. Create By means of a balanced system of electrode transformer, feeder and auxiliary capacities, the minimum or zero currents flow through the parasitic capacitance of the intermediate shading shield 20 and the secondary circuits of the transducer, or any external, independent circuits. - induced by a disturbing signal without the need for a proper grounding of the common shielding 20 and the use of complex and large-scale filter circuits. In the case of the screening foils 12 and the common screening shield 20 with the resetting or grounding conductor 3, a reduction in the magnitude of the currents caused by the interference signal flowing through the resetting or grounding conductor 3 is achieved, thereby reducing interference by magnetic induction. This connection according to the invention can be used in all devices operating in a pulse switching mode in which it is possible to connect a switching element between two sections of a suitable split load.

Claims (2)

242153 PREDMET A circuit for suppressing interference in pulse converters consisting of a switching element and a power transformer, without the need for a grounding conductor, characterized in that the switching element (4) is connected between two primary split wave divisions (7) of the power transformer ( 5), preferably the layers of the individual primary winding sections (7) connected to the supply lines (1) are arranged so as to be adjacent to the secondary winding (8) placed between the individual sections of the primary winding (7), wherein preferably, between the secondary winding (8) and the primary winding sections (7), interconnected shielding foils (12), which are also connected to the core (6) of the power transformer (5), are located one above the other. and also connected by a conductor (15) or via a condenser (18) to an earth or reset conductor (3). An interference suppression circuit according to claim 1, characterized in that the switching element (4) and the power transformer (5) are covered by a shielding cover (20) which is connected to the electrodisplacement element (4) by an auxiliary capacitor (17) and which is also a conductor (15) or a capacitor (18) galvanically connected to the grounding or zeroing conductors (3). 2 sheets of drawings