SU1690142A1 - Dc voltage converter - Google Patents

Abstract

The invention relates to electrical engineering and may be used in the design of secondary power sources. The goal is to increase efficiency and reliability by improving startup conditions. The device contains a self-exciting inverter 1, the inputs of transistors 5, 6 of which are connected via current-limiting resistors 20, 21 to the capacitor 19. The master oscillator 13 produces start-up pulses. With the appearance of a clock pulse on the windings of the transformer 14, the process of resorption of the saturated transistor 5 begins, after locking it, the magnetizing current of the transformer 2 switches to the semi-winding 23 and dissolves the charge carriers from diode 25, After locking the diode 25, the magnetizing current switches to winding 4 and changes the floor the voltage on the windings of the transformer 2, resulting in the inclusion of transistors. 2 Il.

Description

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The invention relates to electrical engineering and can be used in secondary power sources.

The goal is to increase efficiency and reliability by improving startup conditions.

FIG. 1 shows an electrical circuit of a DC converter; in fig. 2 - shows time diagrams of voltages on elements.

The converter contains a self-excited inverter 1 with an output transformer 2, the primary half windings 3, 4 of which are included in the collector circuits of transistors 5, 6. The control half windings 7, 8 of the transformer 2 are connected by extreme terminals through resistors 9, 10 to control transitions of transistors 5, 6, which are shunted by diodes 11, 12. The pulse generator 13 is connected to the output of transformer 14. The additional winding 15 is shunted by diode 16, the cathode of which is connected to the minus, power bus, and the anode to the junction of control uobmotok 7 and 8. The winding 17 of the transformer 14 is connected through a diode 18 to a capacitor 19 which is connected to the control transitions of transistors 5, 6 through resistors 20, 21.

The device works as follows. The master oscillator 13 generates voltage pulses hl (Fig. 26), under the action of which the charge of the capacitor 19 occurs (Fig. 2c). At the same time, the voltage pulse removed from the winding 15 of the transformer 14 cuts off the currents that keep the transistors 5, 6 with the output voltage Ube (Fig. 2a) in the closed state. After the disappearance of the voltage pulse on the windings of the transformer 14, the discharge current of the capacitor 19 flowing through

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cut resistors 20, 21 and the base-emitter transitions of transistors 5, 6, slightly opening them. Due to the non-identical characteristics of these transistors, one of them, for example, 5, opens up more and becomes saturated due to the positive feedback between the collector and base windings, and transistor 6 is locked.

Under the action of the voltage applied to the semi-winding 3, 4 of the transformer 2, the magnetization tsz increases, flowing from the beginning to the end of the winding. At the same time, the output filter capacitors 22 are charged.

With the appearance of a clock pulse on the windings of the transformer 14, the minority charge carriers from the saturated transistor 5 are resorbed by the current flowing through the circuit: the winding 15 of the transformer 14 - emitter - base transition of the transistor 5 - resistor 9 - half winding 7 - winding 15. At the same time Circuits: winding 15 — diode 12 — resistor 10 — semi-winding 8 — winding 15 a current flows which keeps the transistor b in the closed state.

After the transistor 5 is locked, the magnetizing current of the transformer 2 flowing through the half-winding 3 and the transistor 5 switches to the half-winding 23 and, flowing from the beginning to the end of the half-winding, resolves the charge carriers from the previously conducted diode 24, the polarity of the voltage on the windings the transformer remains unchanged.

After locking the diode 24, the magnetizing current switches to the half-winding 4 and, from the beginning to the end of the half-winding,

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changes the polarity of the voltage U2 (Fig. 2d) on the windings of the transformer 2, as a result of which the transistor 6 is turned on by the current flowing through the circuit: the half winding 8 of the transformer 2 - the resistor 10 - the base-emitter junction of the transistor 6, the diode 11 - the resistor 9 - the half winding 7

Further processes in the converter proceed as described above.

Claims (1)

Claims of the Inverter A DC converter containing a self-excited inverter with an output transformer, the primary half windings of which, connected to the first input terminal, are connected to the collector circuits of the transistor, the control transitions of which are bridged by reverse diodes, the control half windings connected to the bases of their bases. through the base resistors, pulse generator with a pulse transformer, the first and second current-limiting resistors, two diodes and a capacitor differing from that, in order to increase efficiency and reliability by improving the starting conditions, the pulse transformer is equipped with two additional windings, the first of which is shunted by the first diode, the cathode connected to the second input terminal, and the anode to the connection point of the control half windings, the second additional winding through the second The diode is connected to a capacitor, which is connected to the control transitions of the transistors through the first and second current-limiting resistors. 1 and but at Ul9 / H / H / H N, FIG. 2