SU930520A2

SU930520A2 - Device for shaping control pulses of thyristors

Info

Publication number: SU930520A2
Application number: SU802983924A
Authority: SU
Inventors: Ярослав Иванович Явдошак; Владимир Тимофеевич Гращенков
Original assignee: Всесоюзный Научно-Исследовательский Институт Электромашиностроения
Priority date: 1980-09-19
Filing date: 1980-09-19
Publication date: 1982-05-23

Description

1one

Изобретение относитс к преобразовательной технике.The invention relates to a converter technique.

По основному авт. св. № 782132, известно устройство дл формировани импульсов управлени тиристором , .содержащее источник питани и выполненный на каскадно соединенных транзисторах усилитель, выход которого включен в цепь управлени тиристором, стабилитрон, резисторы и конденсатор и диод. Причем диод включен последовательно с конденсатором в провод щем дл тока разр да направлении между коллектором первого и базой второго транзисторов . Обща точка диода и кон енсатора через резистор соединена с зажимом источника питани l.According to the main author. St. No. 782132, a device for generating a thyristor control pulse, a power source and an amplifier connected to cascade transistors, the output of which is included in the thyristor control circuit, zener diode, resistors and a capacitor and a diode, is known. Moreover, the diode is connected in series with a capacitor in the conductive direction for the discharge current between the collector of the first and the base of the second transistors. The common point of the diode and capacitor is connected via a resistor to the power supply terminal l.

Это устройство позвол ет, получать импульсы специальной формы дл управлени тиристором.This device allows you to receive pulses of a special form to control the thyristor.

Однако при этом длительность импульса определ етс временем полного зар да конденсатора и не может бытьHowever, the duration of the pulse is determined by the full charge time of the capacitor and cannot be

уменьшена без ущерба дл формы импульса , а именно, без уменьшени длительности той части импульса, где ток превышает номинальное значение тока управлени тиристора. Это об сто тельство несколько снижает верхнюю границу диапазона частот следовани импульсов и понижает надежность устройства.reduced without prejudice to the pulse shape, namely, without reducing the duration of that part of the pulse where the current exceeds the rated value of the thyristor control current. This circumstance somewhat reduces the upper limit of the pulse frequency range and reduces the reliability of the device.

.Кроме того, с приходом помехи по цепи питани возможен подзар д конденсатора и прохождение ложного импульса через управл ющий переход тиристора.In addition, with the arrival of interference on the power supply circuit, capacitor charge may occur and a spurious pulse passes through the thyristor control junction.

Цель изобретени - повышение надежности .The purpose of the invention is to increase reliability.

Claims

This goal is achieved in that a threshold element is inserted into the device for generating pulses by a thyristor, which is connected to the charge circuit of the capacitor in a direction that conducts the charge current between the base of the second transistor and the capacitor plate. Fig, 1 shows a diagram of the proposed device; Fig.2format output pulses. A device for generating control pulses T1 by a resistor contains a source 1 of a power supply, any and performed on two cascade-connected transistors 2 and 3, resistors 4-6, a capacitor 7, a diode 8, a stabilizer 9 and a dynistor 10 whose output is connected to a thyristor control circuit 11. In the initial state, the cascade-connected transistors 2 and 3 of the amplifier are closed, and the capacitor 7 is charged at the voltage of the source 1 of the power supply. The input signal in the form of a narrow rectangular pulse of positive polarity arrives at the base of the transistor 2. ican 2 and 3 are opened and the leading edge is formed and shelf 3.rJ control pulse. At the same time, the condensate 7 is discharged through the transistor 2 and the diode 8, and due to the small time of the discharge circuit, it detects the discharge before the end of the input pulse. In this case, the transistor 3 operates as a nonlinear resistance, implemented in conjunction with the Zener diode 9 and the resistor b, the control current stabilization. At the moment of termination of the input pulse t, transistor 2 is closed. .and capacitor 7 starts to charge along the circuit: plus power supply 1 - resistor 5 - dynistor 10 -, ne base-emitter of transistor F 6 torus - minus power supply 1. As the capacitor charges, a back falling portion of the control pulse is formed: the duration of which Q is determined by a constant 4 times the 1deg of charge. Due to the presence of the dynistor 10, the falling portion of the control pulse terminates at the level of the SCR hold direction, as this closes, breaking the charge circuit of the capacitor 7. This allows a slight increase in the pulse frequency and also increases the reliability of the device. In addition, since the switching voltage of the dynistor is chosen slightly lower than the supply voltage of source 1, it will open until the capacitor is open. is discharged to an appropriate voltage, which provides protection both from interference, over the power supply circuit, and from short interference at the input of the transistor

2. Thus, the introduction of a threshold element into the device improves reliability by improving the noise immunity of the device. Claims An apparatus for generating a thyristor control pulse according to the author. St. No. 732132, characterized in that, in order to increase reliability, it is provided with a threshold element included in the charge circuit of the capacitor in the direction conducting for charge current between the base of the second transistor and the capacitor plate. Sources of information accepted in this review during examination 1. USSR Copyright Certificate No. 782132, cl. H 02 R 13/18, 1978.

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FIG. 2