SU1312700A1 - D.c.voltage converter - Google Patents

Abstract

The invention relates to electrical engineering and can be used to charge a storage capacitor and then discharge it through a switch to a load, as well as a controlled constant voltage source when operating at a constant load. The purpose of the invention is to increase the reliability and expansion of the frequency range of operation. The converter contains a power source 1, to the DC terminals of which two circuits are connected. The first circuit consists of a series-connected primary winding of a pulse transformer 2, thyristors 3,4 and a transistor 5. The second circuit consists of series-connected droplets 6, thyristor 7 and capacitor 8. Between the common points of connection of thyristors 3,4 and thyristor 7 with capacitor 8 is on a diode 9, shunted by a resistor 13. A load circuit is connected to the secondary winding of the transformer 2 through the rectifier I2. Due to the inclusion of the droplets 6, the inductance of which may be less than the inductance of the primary winding of the transformer 2, the time for pumping energy from the capacitor 8 to the power source 1 is reduced, which increases the conversion frequency and also eliminates the discharge of the capacitor 8 through the transistor 5 even when the thyristors start up 3.4. 1 il. a b (/)

Description

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The invention relates to electrical engineering and can be used to power a capacitive load.

The purpose of the invention is to increase reliability and expand the frequency range of work.

The drawing shows an electrical circuit of a DC converter.

The converter contains a power source 1, a circuit connected to it from a series-connected primary winding of a pulse transformer 2, thyristors 3 and 4, and transistor 5, as well as a chain of series-connected droplets 6, third thyristor 7 and capacitor 8. General connection point of thyristor 7 and capacitor 8 through diode 9 is connected to the common connection point of thyristors 3 and 4. The secondary winding of transformer 2 is connected to load 10 with filter P (storage capacitor) via rectifier 12. Diode 9 is bounded by a resistor 13.

The converter voltage is as follows.

When the thyristors 3 and 4 and the transistor 5 are simultaneously unlocked, the primary winding of the transformer 2 is connected to the power source 1. The polarity of switching on the windings of the transformer 2 is such that the transfer of energy to the load circuit does not occur. The increasing current of the primary winding of the transformer 2 provides for the accumulation of electromagnetic energy in it. When the control signal is removed from transistor 5, energy is accumulated in the primary winding of transformer 2 through the circuit thyristor 3 — diode 9 — capacitor 8 — power supply 1.

After reaching a capacitor 8 voltage equal to the voltage of the power source 1, the stored energy in the transformer 2 begins to flow into the load circuit 10 and partially into the capacitor 8 through the thyristor 3 and diode 9, the capacitor 8 allows turning off the transistor 5 at low instantaneous power and thereby reducing the total dynamic loss in the transistor. During the charging time of the capacitor 8, the thyristor 4 regains its control properties. After termination of charge of condenser B pre02

the current through the thyristor 3 increases, the control properties of which are also restored. At the time of the current termination through the thyristor 3, a control signal is sent to the thyristor 7, which opens it, and the energy of the capacitor 8 through the inductor 6 enters the power source I.

The output voltage is controlled by varying the duration of the conductive state of the thyristors 3 and 4 and the transistor 5, causing a change in the amount of energy recorded in transformer 2. The full cycle of operation consists of the time of energy storage in transformer 2, the time of energy transfer to the secondary circuit through straightener 12 to storage capacitor

11 and in the load and the time of energy pumping from the capacitor 8 to the power source I through the thyristor 7.

Increasing the conversion frequency is achieved by reducing the time for pumping energy from the capacitor 8 to

power source 1 due to the inclusion in the circuit of the drossel 6, whose inductance may be several times less than the inductance of the primary winding of the transformer 2. By converting the conversion frequency, the filter capacitance in the load circuit can be reduced or the pulsation value can be reduced at the same capacity when operating

constant load.

In addition, the inclusion of the droplets 6 eliminates the discharge of the capacitor energy through the transistor 5, even when spontaneous start of the main thyristors.

Claims (1)

Invention Formula five The DC / DC converter containing a pulse transformer, the primary winding of which is connected to the first input terminal with one output for connecting the power source and the other through two thyristors connected in series and the transistor to the second input output, is a common capacitor, with one plate connected to the common output and the other to the anode of the third thyristor and through a chain of parallel-connected diode and a resistor with a common connection point of these two thyristors, and t also load circuit5 313127004 ki connected via an oscillator in the width of the frequency range of operation, the secondary circuit of the transformer is additionally inserted into a choke, including that between the first input terminal in order to increase reliability and the cathode of the third thyristor.