SU1663724A1 - Constant voltage converter - Google Patents

Abstract

The invention relates to converter equipment and can be used in secondary power sources of radio electronic equipment. The purpose of the invention is to increase efficiency. The converter is made by the push-pull circuit of the inverter on power transistors. The unlocking signal is not fed to the input of the next power transistor until the information about closing the locked power transistor comes. Negative bias is applied to the base of the locking power transistor, which allows for more efficient protection of the through-current protection. 1 il.

Description

The invention relates to converter equipment and can be used in secondary power sources of radioelectronic equipment.

The purpose of the invention is to increase efficiency.

The drawing shows a diagram of the device.

The voltage converter consists of an output transformer 1 connected to the collectors of the power transistors 2 and 3, the bases of which are connected to the emitters and collectors of the auxiliary transistors 4 and 5 of the respective arms. The winding 6 of the control transformer is connected to the bases of the power transistors 2 and 3 through the base resistors 7 and 8, in parallel with which reverse Diodes 9 and 10 are connected. The bases of the auxiliary transistors 4 and 5 are connected to the emitters of the power transistors 2 and 3 through resistors 11 and 12, as well as with collectors of transistors 2 and 3 opposite shoulders through resistors 13 and 14.

The Converter operates as follows.

From winding 6, control signals through resistors 7 and 8 and diodes 9 and 10 are fed to the bases of power transistors 2 and 3. Suppose that at the beginning of windings 6 of the transformer a negative is induced, and at the ends - plus, power transistor 2 is open, and transistor 3 is closed. The diode 9 is closed and the base current of the transistor 2 is determined by the resistor 7, the diode 10 is open and the resistor 8 is bridged. The transistor 3 is closed by the negative voltage on the winding 6 minus the voltage drop on the open diode 10. The auxiliary transistor 4 is then closed through the resistor 14 by the positive voltage on the collector of the transistor 3. When the polarity of the voltage on the winding 6 of the control transformer is reversed, the transistor 2 is closed by a negative voltage. At the same time, the closing process is forced, since diode 9 is open, which prevents falling

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the voltage across the resistor 7. This decreases the time during which the transistor 2 is in the open state due to the finite resorption time of the minority carriers in the base region. During this time, the voltage on the collector of the transistor 2 is low and the transistor 5 opens through a resistor 13. The base of the transistor 3 is connected through the open transistor 5 to the base of the transistor 2, to which negative voltages are applied through a diode. Transistor 3 is closed until transistor 2 is closed and the voltage across its collector does not increase. After increasing the voltage across the collector of transistor 2, transistor 5 is closed by the voltage supplied through resistor 13, the negative voltage supplied through the previously opened transistor 5 is removed from the base of transistor 3 by the positive voltage supplied through resistor 8.

When diodes are turned on in parallel with resistors in circuits without power transistors, the closing process of the transistors occurs through open diodes. Simultaneously, the control circuit of the power transistors is blocked by shunting the winding

controlling the auxiliary transistor and connecting the base (locking) of the power transistor to a negative voltage.

Claims (1)

Claims of a DC converter containing a push-pull inverter with an output transformer connected by the midpoint of the primary winding to the first input terminal, the ends of the primary winding are connected to collectors of the power transistors, the emitters of which are connected to the second input terminal, with the middle point of the control transformer winding and one of the terminals of the first resistors, the second terminals of which are connected to the bases of the auxiliary transistors and the first terminals of the second resistors, the second terminals of the cat ryh connected to the collectors of the power transistors of opposite shoulders, the base of which via base resistors connected to ends of a control coil of the transformer, characterized in that, in order to increase the efficiency of parallel base resistors included wheeling diodes and the collectors of the subsidiary transistors are connected to the bases of the power transistors of opposite shoulders.