SU389495A1 - PULSE STABILIZER OF PERMANENT VOLTAGE IN THE TERMINAL - ^ DK! ^? ^ 1 ';: ^ P'z ^ L ^ .. • ^: • ^ • ^^^ J Z'ti-i And ypv * i: ^: h /' '".! Fi-' Mi ' iE - Google Patents

Description

one

The invention relates to the IK field of power conversion equipment and serves to create voltage transformers that are protected from overloads and short circuits.

A known circuit of a pulse voltage constant-voltage regulator of the series type, consisting of a power control transistor and a pulse-width-modulator modulator, made on the basis of an asymmetrical converter. If the transformer winding of this asymmetrical converter In one-half-period applies a voltage of 6 in-Uon, (I - power supply voltage, UOTI - voltage of the reference source), ai to another Uon, then the output voltage

-out Won The disadvantage of this stabilizer is the lack of fast-acting protection against overloads and short-circuits at the output.

The proposed pulse voltage regulator circuit, while maintaining the advantages of the prototype circuit, provides protection against leverage and short circuits in the load circuit by the fact that one winding of an unbalanced converter is connected through a resistor in parallel and the other winding in series with the stabilizer load. Wherein

To provide an external stabilizer characteristic with a short-circuit current lower than the rated load current, a zener diode is switched on in series with the resistor and winding of the non-symmetric converter connected in parallel with the load. In addition, the reference source is made in the form of a parallel-connected capacitor and a low-power regulating transistor, the input of which is connected to the output of the voltage measuring element at the load.

FIG. 1 shows a pulse stabilizer circuit; in fig. 2 shows the connection of additional elements in the circuit.

The proposed stabilizer works as follows.

Let an asymmetrical transistor 1 be turned on, then a voltage is applied to the winding 2 of transformer 3 with the polarity shown in the diagram, which is equal to t / Bx-Uon-. This turns on the power transistor 5 using the winding 4 of transformer 3 flows along the circuit: plus the source of the power supply, transistor 5, choke 6, load 7, winding 8 of the transformer 3, minus the power supply. After the transformer 3 is saturated, transistors 1 and 5 are turned off. The transistor 9 is turned on, the transformer 3 is re-magnetized from the voltage Uon, ai the load current flows in a loop: choke 6, load 7, winding 8, diode 10. The reference source is created in parallel by the Zener diode II and the capacitance 12, which are connected to the power source through the resistor 13 The magnetizing forces of the windings / 4 and 8 of the transformer 3 are directed towards each other, and TOiK in the frame 14 is almost independent of the load, and the current in the winding 8 is equal to the load current. When selecting a resistor 15 of an appropriate size, so the discharge of the capacitor 12 (with the transistor 9 running) due to the flow of such a load through the winding 8 is less than the charging current of the capacitor 12 through the resistor 13. Therefore, the voltage at capacitance 12 is determined by a zener diode // (t / on ). As the load current rises to a certain permissible value / ndop, the discharge of the capacitor 12 along the circuit: capacitor 12, winding 2, transistor 9 exceeds its charge current through the resistor 13. The voltage Hai of the capacitor 12 decreases, and therefore the voltage across the load decreases 7. With a further increase in the load current, a monotonic decrease in the duty cycle of the transistor 5 occurs, and consequently, the voltage across the load. In the entire range of external characteristics up to a short circuit, all active elements of the stabilizer work in a key mode. If Zener diode 16 is turned on in series with resistor 15 and winding 14 (see Fig. 2), the current through it will be determined by the voltage t / out-Uou- Then, when the voltage at the stabilizer output decreases, the above current will decrease very sharply and the stabilizer characteristic will correspond to the external characteristic of the shunt generator. By selecting the resistance value 15 and the stabilization voltage of the Zener diode 16, it is possible to obtain any given form of the external characteristic of the stabilizer. When replacing the Zener diode 11 ((Fig. 1) with any control element and an element (for example, transistor 17), whose input is connected to the measuring organ 18 (Fig. 2), the stabilizer acquires a new important quality: the voltage at the stabilizer output does not depend on the current loads, and sudden changes in the supply voltage are handled by the stabilizer inertialess The subject of the invention 1. An impulse regulator of a constant voltage of the series type, consisting of a power control transistor and a pulse-width modulator made On the basis of an asymmetric converter, and a voltage measuring unit at the load, characterized in that, in order to provide protection against overloads and short circuits in the load circuit, one of the transformer windings of the asymmetric converter is connected via a resistor in parallel, and the other winding is in series with the stabilizer load 2. The stabilizer according to claim I, which is distinguished by the fact that, in order to provide a given shape of the external characteristics of the stabilizer, in series with the winding of an asymmetrical converter: a resistor connected parallel to the load, the zener diode is turned on. 3. Stabilizer according to claim 1, characterized in that, in order to increase the control accuracy while maintaining speed, the reference source of the asymmetric converter is made in the form of a parallel-connected capacitor and a low-power control transistor, the input of which is connected to the output of the voltage measuring component on the load.

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