SU907731A1 - Low voltage ac voltage-to-dc voltage converter - Google Patents

Description

(54) LOW-VOLTAGE VOLTAGE VOLTAGE CONVERTER TO CONSTANT

The invention relates to electrical engineering, in particular, to converters of alternating voltage to constant voltage and can be used in low-voltage power supplies of electronic equipment and computing equipment.

Converters of alternating voltage into constant voltage are known that contain a single-phase converter transformer, the valve winding of which is connected to a rectifying diode bridge I.

However, this converter is characterized by a short duration of transients when the load is switched on due to the acceleration of the load current due to the energy accumulated in the capacitor.

In addition, at an output voltage level of 2.0-6.0 V, the voltage drop across two series-connected diodes becomes commensurate with the output voltage, which drastically reduces the efficiency of the converter.

A low voltage AC / DC converter is also known, which contains a converter transformer and two rectifying diodes.

The ends of the valve winding are connected to rectifying diodes, one of the terminals of the electrodes of the same name are combined to form one output terminal, and the outlet from the midpoint of the valve winding forms 5 other output terminal.

In each half-cycle of the frequency of the supply current, a load current flows through a circuit formed by half of the winding from the midpoint and one of the rectifying diodes for which the positive half half-life of the EMF of half of the winding coincides with its direct conductivity. In this case, at each moment of time, only one rectifying diode is in the conducting state, which in the case of direct voltage drop, for example, on silicon diodes is 0.7–1.0 V and allows a significant increase in the efficiency of the converter at low output voltages x 2.

A disadvantage of the known device is that the transient process

Claims (3)

When a low-voltage converter is turned on for a load with an inductance (for example, an inductive-capacitive filter), it has a longer duration. The purpose of the invention is to improve the dynamic properties of the low-voltage converter. The goal is achieved by the fact that in a low-voltage AC-DC converter, containing a converter trans (| ormator and two rectifying diodes, one terminals of the same electrodes of which are combined and their common point forms one of the output terminals, the valve winding of the converter transformer is in the form three strips of twisted foil, with one ends of two foil strips connected to other corresponding output electrodes of the rectifying diodes, and one end of the third foil strip of the reverse There is another output pin. In addition, all the foil strips are made equal in width, the strips connected to the rectifying diodes are placed on both sides of the third stripe. Moreover, the two foil strips connected to the rectifying diodes are made in the same width with respect to the third band. Fig. 1 shows a diagram of a low-voltage AC-to-constant voltage converter with radial placement of the foil strips of the transformer's valve winding; in fig. 2 is a diagram with an axial arrangement of foil strips. The low voltage AC / DC voltage converter (Fig. 1) contains a converter transformer 1 and two rectifying diodes 2 and 3, the same terminals of the same electrodes of which are combined to form the first output terminal 4. The converter transformer 1 contains the primary winding 5 and the valve winding , made in the form of three strips 6 - 8 of twisted foil, with one ends of the foil strips b and 8 connected to the rectifier diodes 2 and 3, respectively, and one end of the third stripe 7 forms the second output terminal 9. All pho The lg strips 6–8 are of equal width, with the strips 6 and 8 placed on both sides of the third stripe 7. A dielectric film 10 is placed between the foil strips 6 and 7 and 7 and 8. An equivalent inductance is included in the load circuit. The low voltage AC / DC voltage converter (Fig. 2) contains a transformer 11 and two rectifying diodes 12 and 13, some of the same electrode terminals are combined to form the first output terminal 14. The converter transformer 11 contains the primary winding 15 and the valve winding, made in the form of three strips 16-18 of twisted foil, with one of the ends of the foil strips 16 and 18 connected to the rectifying diodes 12 and 13, respectively, and one end of the third stripe 17 forms the second output you od foil 19. Two strips 16 and 18 are of equal width and are arranged in one plane relative to the third strip 17. Between the strips 17 L and W 1B .i. 17, a dielectric film 20 is placed. An equivalent inductance is included in the load circuit. The operation of the low voltage converter is carried out as follows. When the primary winding of the converter transformer is turned on to the AC network, the alternating current is induced in the turns of the valve winding made of foil strips. Under the action of positive half-waves of the emf of the corresponding bands on the rectifying diodes, their alternating opening occurs, which ensures the full-wave conversion of the alternating voltage into a constant one. In this case, every moment of opening of the rectifying diodes is accompanied by a sharp increase in the load current due to the discharge of energy accumulated on the foil strips of the valve winding. At each time, only one diode is in the open conducting state, which causes a small loss of the converter on the rectifying diodes. Thus, the implementation of a valve winding of a converter transformer and foil strips separated by a dielectric is identical to the inclusion of a capacitor valve winding into the circuit, the accumulation of energy in which improves the dynamic properties of a low-voltage converter by forcing a rise in current when the load is switched on. Claim 1. A low-voltage AC-to-DC converter containing a converter transformer and two rectifying diodes, one terminals of the same electrodes of which are combined and their common point forms one of the output terminals, characterized in that, in order to improve the dynamic properties, the valve the winding of the converter transformer is hollowed out in the form of three strips of twisted foil, with one ends of the two foil strips connected to other relevant terminals of the straightening electrodes Yelnia diodes, and one end of the third foil strip forms another output terminal. 2. A low voltage converter according to Claim 1, characterized in that all the foil strips are made equal in width, the strips connected to the rectifying diodes being placed on both sides of the third stripe. 3. The low-voltage converter according to claim 1, characterized in that the two foil strips connected to the rectifying diodes are made equal in width and placed in the same plane with the third strip. Information sources, taken into account in the examination If-. UL 1. Alykumov G. A., et al. Calculation of transient processes in a bridge rectifier with a pre-connected capacity. “Electrical Engineering, 1979, No. 9, p. 14, fig. 1 a. 2. Kaganov I. L. Industrial electronics. M., “Higher School, 1968, p. 469, fig. 7.48 a.