SU1377947A1 - Device for limited starting current of secondary power supply source - Google Patents

Abstract

This invention relates to electrical engineering, in particular, to relay protection. The purpose of the invention is to increase the reliability of the device. The presence of an RC circuit - a resistor 11 and a capacitor 12 - contributes to the fact that the voltage at the output of transistor switch 5 rises smoothly, which prevents a sharp increase in the load current 18. Time delay of time relay 16 is necessary so that voltage 3 did not occur avalanche-like transition of the transistor switch 5 to the on-line mode, which would lead to an unacceptable inrush of current in the load 18. 1 Il.

Description

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The invention does not relate to electrical engineering and can be used in direct current circuits for a smooth start-up of a secondary power source and protection against overloads.

The purpose of the invention is to increase the reliability of the device.

The drawing shows a circuit diagram of the device.

The device for limiting the starting current of the secondary power source 1, which includes the oscillator 2 and the voltage converter 3, contains a resistor current sensor 4, a transistor switch 5, a resistor 6 and a zener diode 7, control unit 8, which can be made in the form the DC amplifier 9 and the thyristor 10, the time driving the CS circuit - a resistor 11 and a capacitor 12, a control transistor 13 with a resistor 14 in the collector circuit, a recharge current rectifier 15, a time relay -16 with a closing contact 17, a load 18 is connected to the output pr educator 3.

The device works as follows.

When switched on in the start-up mode, the auto-generator 2 of the secondary power source 1, which pulses are fed to the input of the converter 3, is energized. At the same time, the current through the resistor current sensor 4 is fed to the inputs of the amplifier 9 of the constant current of the control unit 8, time defining the KS circuit. The capacitor 12 is charged before the voltage of the unlocking of the control transistor 13, which, when unlocked, opens the transistor switch 5 through the charging current rectifier 15, but does not go into saturation mode. In this case, the voltage converter 3, the time relay 16 and the load 18 are supplied with power. The presence of an RC circuit - a resistor 11 and a capacitor 12 - contributes to the fact that the voltage at the output of the transistor switch 5 is smooth, which prevents a sharp rise of the load path 18. The smoothness of the load current increase is determined by the constant time of the KS circuit.

The time relay starts counting the time delay. When a relay is triggered, 16 times its contact 17 closes and from the converter 3 voltage through the rectifier 15 of the feed current is fed to the base of the trans0

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a resistor key 5, which goes into saturation mode. The time lag is necessary so that when the charging current is supplied from the voltage converter 3, the avalanche-like transition of the transistor switch 5 to the saturation mode does not occur, which can lead to an unacceptable current surge in the load 18.

In the event of a short circuit in the load 18 or in the secondary power source 1, the voltage on the resistor current sensor 4 rises to the second and third inputs of the control unit 8, the first input of which already has a stabilized voltage from the power source. The voltage from the resistor current sensor 4, amplified by the DC amplifier 9, is applied to the control electrode of the thyristor 10, which is opened. In this case, the control transistor 13 and the transistor switch 5 are closed and the power supply to the converter 3 of the voltage of the secondary power source 1 and the load 18, which are disconnected from the network, is cut off.

The present invention allows to increase the reliability of the device in the start-up and short-circuit mode of the secondary power source.

Formula of Invention

Device to limit the starting current of the secondary power source - 1

No, which includes a series-connected auto generator and a voltage converter, containing a series-connected resistor current sensor and collector of a transistor switch connected to the first power supply terminal, the emitter of which is intended to be connected to the input terminal of the voltage converter, connected in parallel with the source input terminals power series-connected resistor and zener diode, the cathode of which is connected to the first input of the control unit, the second and third inputs to The first is connected to the first and second outputs of the resistor current sensor, respectively, while the first output of the resistor current sensor is designed to be connected to the input terminal of the autogenerator, characterized in that, in order to increase the reliability of operation, an RC time control circuit is added with a resistor in the collector circuit, a make-up current rectifier and a time relay with a 1-fold contact, while the time specifying the RC circuit is connected between the third input of the control unit and the common bus, its common point dinena yield control unit and control base n Oleg Zhegoyev

transistor, the collector of which is connected to the collector of the transistor switch, the base of which is connected to the transmitter terminal of the control transistor through a charge current rectifier, the first output of which is directly, and the second through the closing contacts of the time relay are intended to be connected to the first and second voltage converter outputs, A time relay is connected between the emitter of the transistor switch and the common bus.

Claims (1)

Claim A device for limiting the starting current of a secondary power source, which includes a serially connected oscillator and a voltage converter, containing a resistor current sensor and a transistor switch collector connected to the first terminal of the power source, the emitter of which is designed to connect to the input terminal of the voltage converter parallel to the input terminals of the power source, a resistor and a zener diode are connected in series, the cathode of which it is single with the first input of the control unit, the second and third inputs of which are connected to the first and second terminals of the resistor current sensor, respectively, while the first output of the resistor current sensor is designed to connect to the input terminal 3 of the oscillator, characterized in that, in order to increase the reliability of operation, additionally introduced a timing RC circuit, $ a control transistor with a resistor in the collector circuit, a make-up current rectifier and a time relay with a make contact, while between the third input of the control unit and A time-consuming RG-circuit is connected, its common point is connected to the output of the control unit and the base of the control transistor, the collector of which is connected to the collector of the transistor switch, the base of which is connected to the emitter of the control transistor through the charging current rectifier, the first output of which is directly and the second one, through the closing contacts of the time relay, is used to connect to the first and second outputs of the voltage converter, the time relay is connected between the emitter of the transistor switch and the common by bus.