SU1252885A1 - Voltage converter - Google Patents

Abstract

The invention relates to electrical engineering and is used in secondary power sources. The purpose of the invention is to increase reliability by reducing the voltage across the power transistor. When the converter starts, a control pulse arrives at the thyristor 11 and opens the transistor (T) 6. As the current increases in the primary winding of the transformer 5, its core begins to saturate and the locking process of the T 6 develops. As a result, the current in the thyristor I1 decreases and it turns off . After the thyristor 11 is turned off, the voltage at the closed transistor decreases abruptly and with further recharging of the capacitor (K) 7 is distributed between the series-connected switching elements in proportion to their resistance. Perezar q 7 is caused by an oscillatory circuit formed by the K 7 and the inductances of gdatok transformers 1, 4 and load 2, 3. The introduction of the thyristor If reduces the voltage to T 6. I Il. sl to ate Nd 00 00 ate

Description

The invention relates to converter technology and can be used in the design of secondary power sources, in particular high voltage AC sources.

The object of the invention is to increase reliability by decreasing the voltage across the power transistor.

The drawing shows an electrical circuit of a voltage converter.

The converter contains a series circuit including the primary windings of the output transformer 1, with active-inductive loads 2 and 3, the pulse transformer 4, controlled by a transformer 5 and the power transistor 6, an emitter connected to the negative terminal of the power supply, and parallel to the connection of the primary windings the output 1 and the pulse 4 transformers are connected to a capacitor 7, and a reverse diode 8 is connected to the control junction of the power transistor, as well as one secondary winding of the transducer anformator 4 through a diode 9 and a secondary winding controlled to a transformer 5 through an additional capacitor 10. A thyristor 11 with an anodome m connected to the positive output of the power source, a cathode to the specified serial circuit, and a control transition of the thyristor 11 through diode 12 are connected to the device other is the secondary winding of a pulse transformer 4.

The device may also contain diodes 13 and 14, shunt the power terminals of the transistor and the thyristor, to improve the quality of the transient process with an abrupt decrease in the voltage of the power source, as well as a resistor 15 and a trigger device (not shown) that ensures reliable start-up of the converter.

The device works as follows.

When a first triggering pulse is received from the triggering device on the thyristor 11 and the open transistor 6, through the base-emitter junction of which the initial bias current is created by the resistor 15, the capacitor 7 is charged with the polarity indicated in the circuit

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The supply source voltage and currents through the primary windings of transformers 1.4 and 5 are increasing. As the current increases in the primary winding of the transformer 5, its core begins to saturate and blocking develops the process of locking transistor 6. As a result of locking the transistor, the current in the thyristor circuit I1 becomes less than the holding current and it turns off. During the turn-off time of the thyristor, the voltage on the collector of the transistor increases during the recharge of capacitor 7 through the primary windings of Transformers 1 and 4. After turning off the thyristor, the voltage on the closed transistor abruptly decreases and subsequently the recharging of the capacitor 7 is distributed between the series-connected switching elements in proportion to them resistor m. Perezar d capacitor 7 due to the oscillatory process in the circuit formed by this capacitor, the inductances of the windings tr anformators "and 4, active-inductive loads 2 and 3.

The thyristor is switched on again by a signal coming from the winding of the pulse transformer 4 through diode 12 at the moment when after one cycle of oscillations the capacitor 7 is recharged to the voltage of the power supply and the polarity of the current in the primary windings of transformers 1 and 4 changes. the same moment from the transformer 4 through the diode 9 is supplied a synchronization pulse to the base of the transistor. After turning on the thyristor and the transistor, the process is repeated.

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Thus, the introduction of a thyristor provides a significant reduction in the voltage across the transistor, which increases the reliability of the entire device, especially when designing voltage converters with a high-voltage power source.

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Claims (1)

Invention Formula A voltage converter containing a series circuit including the primary windings 55 of the output, pulse, and control transformers and a power transistor connected by an emitter to the negative terminal of the power source 3J2528854 Nor, moreover, parallel to the primary, that, in order to ensure reliable output and pulse windings by reducing the voltage on the transformers, a co-voltage transistor is connected, a torus is inserted into it, and a thyristor is connected to the control transition, an anode connected to a second transistor — a reverse diode , 5 to the positive output of the source as well as the secondary winding of the pulse-powered cathodes to the serial transformer through the diode of another circuit, and to the control junction the secondary winding of the control trans-thyristor through the diode The reformer is supplied via an additional con-secondary secondary winding of a pulse-capacitor, which differs from the 10th transformer.