RU2778143C1 - Secondary power source - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering, namely to pulse DC voltage converters, and is intended for generating output (galvanically separated) constant voltages from each other and can be used as a secondary power source (SPS) of automation systems and electronic equipment. The SPS contains a square-wave generator, a block of buffer elements, a power amplifier, the first input of which is the output of the first external power source, the first output transformer, the outputs of which are connected to the inputs of the first rectification and filtering unit, the output of which is the first output of the device. A control signal generator, a control transformer, a current limiter unit, a second third and fourth output transformers are introduced, the outputs of which are connected to the corresponding inputs of the second, third and fourth, additionally introduced rectification and filtering units, the outputs of which are the second, third and fourth output of the device. The first, second, third and fourth outputs of the current limiter block are connected to the first inputs of all output transformers, the second and third inputs of which are interconnected and connected to the outputs of the power amplifier. The input of the current limiting block is the output of the first external power supply. The input of the square-wave generator, the second input of the control signal generator and the third input of the block of buffer elements are interconnected and are the output of the second external power supply. The output of the rectangular voltage generator is connected to the control signal generator, the outputs of which are connected to the first and second inputs of the block of buffer elements. The outputs of the control transformer are connected to the second and third inputs of the power amplifier.

EFFECT: obtaining galvanically isolated voltages, the possibility of increasing their number, protection against high (overload) currents and overloading of the SPS outputs.

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Description

The invention relates to electrical engineering, namely, to pulse DC voltage converters and is intended for generating output, galvanically isolated from each other, constant voltages, and can be used as a secondary power source (SPS) of automation systems and electronic equipment.

Known "Stabilized voltage converter with digital microcircuits" (see patent RU No. 2014713 priority dated 07/08/1991, published 06/15/1994 B.I. No. 20), containing a rectangular voltage generator with antiphase outputs, a push-pull power amplifier with the first and second transistors , a node for eliminating through currents, a stabilization device, a power supply for microcircuits and an output transformer, the beginning and end of the primary winding of which are connected to the collectors of the first and second transistors of the power amplifier, respectively, the secondary winding is connected through a rectifier to the output of the converter, and the additional winding of the transformer with an average output connected to the node by extreme terminals to exclude through currents. The first and second buffer elements with an open collector are introduced, the inputs of these elements are connected to the outputs of a rectangular voltage generator, and the outputs through the first and second current-limiting resistors are connected to the bases, respectively, of the first and second p-n-p transistors of the power amplifier, the node for eliminating through currents is made on the third and fourth p-n-p transistors, the emitters of all four transistors are connected to the middle terminal of the additional winding of the output transformer and to the output terminal of the positive polarity of the source for powering microcircuits, the base of the third transistor through the third and fourth resistors is connected, respectively, to the beginning of the additional winding of the output transformer and to the output of the second buffer element, the base of the fourth transistor through the fifth and sixth resistors - respectively to the end of the additional winding and to the output of the first buffer element, the collectors of the third and fourth transistors are connected to the bases of the first and second transistors of the amplifier power, the output of the stabilization device, which is made in the form of an adjustable voltage driver of negative polarity, is connected to the middle terminal of the primary winding of the output transformer, and the secondary winding of this transformer is equipped with taps connected to the rectifiers in accordance with the number of required output voltages, the output of one of the rectifiers through the feedback circuit connected to the control input of the stabilization device.

The disadvantages of the above device are:

- insufficient number of output voltages, and with different ratings;

- lack of galvanic isolation between output voltages;

- the regulating driver regulates the output voltages in the analog mode, which reduces the efficiency (efficiency factor) of the device.

This device is the closest in technical essence to the claimed device and therefore selected as a prototype.

The problem to be solved is the creation of a secondary power source that is resistant to external influencing factors (VVF), has several output voltages with galvanic isolation, has high efficiency, reliability and operates in a wide temperature range.

The achieved technical result is to obtain galvanically isolated voltages, the possibility of increasing their number, obtaining a high efficiency of the VTS, providing protection against high (overload) currents during exposure to VVF and when overloading the VTS outputs, maintaining the functioning of the VTS in a wide range of operating temperatures.

To achieve a technical result in a secondary power source containing a square-wave generator, a block of buffer elements, a power amplifier, the first input of which is the output of the first external power source, the first output transformer, the outputs of which are connected to the inputs of the first rectification and filtering unit, the output of which is the first output of the device, the novelty is that a control signal generator, a control transformer, a current limiter unit, a second, third and fourth output transformers are additionally introduced, the outputs of which are connected to the corresponding inputs of the second, third and fourth additionally introduced rectification and filtering units, the outputs of which are the second , the third and fourth outputs of the device, the first, second, third and fourth outputs of the current limiter block are connected to the first inputs of all output transformers, the second and third inputs of which are combined and connected to the outputs of the amplifier of the power limiter, the input of the current limiting unit is the output of the first external power source, the output of the square-wave generator is connected to the first input of the control signal generator, the outputs of which are connected to the first and second inputs of the block of buffer elements, the outputs of which are connected to the inputs of the control transformer, the outputs of which are connected to the second and third inputs of the power amplifier, the input of the square-wave generator, the second input of the control signal generator and the third input of the block of buffer elements are interconnected and are the output of the second external power supply.

A new set of essential features in the claimed device makes it possible to increase reliability due to the introduction of a block of current limiters, as well as through the use of a small number of VIP components on active elements (semiconductor, amplifying) and a minimum number of analog active ERI, and operating only in the key mode.

In FIG. 1 is a functional diagram of the secondary power supply. In FIG. 2 shows the diagrams of the operating signals of the VIP.

The secondary power source contains a square-wave generator 1, a block of buffer elements 4, a power amplifier 7, the first input of which is the output of the first external power source 6, the first output transformer 9, the outputs of which are connected to the inputs of the first rectification and filtering unit 13, the output of which is the first device output U1. A control signal generator 3, a control transformer 5, a current limiter block 8, a second 10, a third 11 and a fourth 12 output transformers are introduced, the outputs of which are connected to the corresponding inputs of the second 14, third 15 and fourth 16, additionally introduced rectification and filtering units, the outputs of which are the second U2, the third U3 and the fourth U4 output of the device. The first, second, third and fourth outputs of the current limiter block 8 are connected to the first inputs of all output transformers 9, 10, 11, 12, the second and third inputs of which are combined and connected to the outputs of the power amplifier 7, the input of the current limiter block 8 is the output of the first external power source, the output of the square-wave generator 1 is connected to the first input of the control signal generator 3, the outputs of which are connected to the first and second inputs of the block of buffer elements 4, the outputs of which are connected to the inputs of the control transformer 5, the outputs of which are connected to the second and third inputs of the amplifier power 7, the input of the square-wave generator 1, the second input of the control signal generator 3 and the third input of the block of buffer elements 4 are interconnected and are the output of the second external power source 2.

VIP works as follows.

With the power supply from external sources of constant voltages 2 and 6, the rectangular voltage generator 1 begins to form a periodic sequence of pulses with a period "T", a duration "t" and a pause "τ" (see Fig. 2a). The duration value "t" is selected depending on the inductance of the primary windings of the output transformers 9-12. The pause value "τ" is chosen as minimally as possible in such a way that the maximum efficiency of the VIP is ensured, provided that there are no through currents of the transistors of the power amplifier 7.

The sequence of pulses from the output of the square-wave generator 1 is fed to the input of the control signal generator 3, which generates two-phase pulse control signals at its output (see Fig. 2b, 2c), which are then pre-amplified by a block of buffer elements 4.

The signals from the buffer elements 4 are fed to the control transformer 5, which provides galvanic isolation between power supplies 2 and 6, and the coordinated transmission of control signals to the power amplifier 7. Next, the power amplifier 7 amplifies the power control signals that are fed to the output transformers 9-12, which carry out the transmission of signals from the power amplifier to the rectification and filtering units 13-16, providing galvanic isolation between the output signals. The signal at the output of the output transformer is shown in Fig. 2y.

The rectification and filtering units 13-16 convert the AC voltage signals coming from the output transformers into DC voltages U1-U4.

The current limiter block 8 protects the power amplifier through the primary windings of the output transformers by limiting the currents of its transistors during the exposure to the VVF and during overloads of the VIP outputs.

The performance of the proposed device is confirmed by testing its prototypes.

Claims (1)

A secondary power source containing a square-wave generator, a block of buffer elements, a power amplifier, the first input of which is the output of the first external power source, the first output transformer, the outputs of which are connected to the inputs of the first rectification and filtering unit, the output of which is the first output of the device, characterized in that that a control signal generator, a control transformer, a current limiter unit, a second, third and fourth output transformers are additionally introduced, the outputs of which are connected to the corresponding inputs of the second, third and fourth, additionally introduced rectification and filtering units, the outputs of which are the second, third and fourth outputs devices, the first, second, third and fourth outputs of the current limiter block are connected to the first inputs of all output transformers, the second and third inputs of which are interconnected and connected to the outputs of the power amplifier, the input of the current limiter is the output of the first external power source, the output of the square-wave generator is connected to the first input of the control signal generator, the outputs of which are connected to the first and second inputs of the block of buffer elements, the outputs of which are connected to the inputs of the control transformer, the outputs of which are connected to the second and third inputs of the power amplifier, the input of the square-wave generator, the second input of the control signal generator and the third input of the block of buffer elements are interconnected and are the output of the second external power source.

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