SU1737658A1 - Device for control over thyristor - Google Patents

Abstract

SUMMARY OF THE INVENTION: The device comprises a power supply 1, resistors 2, 4, transistors 3, 7, capacitors 5, 6, diode 8, a source of control signal. The power source 1 supplies a pulsating voltage, causing a charge of capacitors 5 and 6. The capacity of the first capacitor is much less than the second. When the transistor 7 is closed, the charge time of the capacitor 5 through the resistor 4 determines the minimum control angle when the charged capacitor 5 causes the single-junction transistor 3 to turn on, which forms the output control pulse. Transistor 7 is used in a controlled resistor mode. When it is opened by a signal from the control signal source 9, the charging time increases due to the introduction of a capacitor 6. 1 sludge.

Description

The invention relates to electrical engineering and can be used in converter equipment.

The aim of the invention is to improve the linearity of the adjustment characteristic,

The drawing shows a diagram of the device.

The power supply 1 is connected via an output limiting resistor 2 to the second base of the unijunction transistor 3 and through the second resistor 4 to the emitter of this transistor 3 and the terminals of capacitors 5 and 6. The latter is connected to the collector of a bipolar transistor 7 by a second output by a counter diode 8. A control signal source 9 is connected to the input of transistor 7.

The device works as follows.

The input of the device is supplied from the thyristor voltage of the rectifier circuit. This voltage is rectified by source 1. Pulsating voltage is applied to the charge of capacitors 5 and 6, the capacity of the first capacitor 5 is 10-30 times less than the capacitance of capacitor 6. The rate of change of voltage on the capacitor 5 varies depending on the resistance value of the transistor 7

At zero resistance of the latter, the charge rate is low, since two capacitors are charged: capacitor 5 directly, and capacitor 6 through an open transistor 7. When the voltage across the capacitor 5 reaches 50-50% 70% of the voltage on the second base, the emitter of the transistor 3 discharges a capacitor 5 to the output (thyristor control transition not shown). Thus, a pulse is generated with a maximum lag time. Transistor 6 is also discharged through diode 8.

With a large resistance of the transistor 7, the capacitor 6 is practically not charged. Only one capacitor 5 is charged. Due to the small capacitance, the charge is fast. The voltage reaches the switching level faster. The pulse at the output of the first base of the transistor 3 is generated with a minimum delay, i.e. formed with a minimum angle. At an intermediate value of the resistance of the transistor 7, the pulse delay is regulated in a wide range (from 15 to 160 °).

Claims (1)

The invention of the device for controlling the thyristor, containing a power source, one output of which is connected to the free output of the resistor of the time setting of the RC chain and, via a limiting resistor, to the first base of the single junction transistor and the other output terminal connected to the common bus emitter , the control input of which is connected to the output of the control signal source, one output terminal and the time of the driving RC-chain to the free output of the capacitor, the midpoint of which is connected to It is a single junction transistor, the second base of which is connected to another output terminal, so that, in order to improve the linearity of the adjustment characteristic, it is equipped with a capacitor and a diode, the anode of which is connected to the common bus, and the cathode to the collector's junction point a bipolar transistor with one terminal of a capacitor, the other terminal of which is connected to the emitter of a single junction transistor.