SU1307517A1 - A.c.voltage-to-d.c.voltage converter - Google Patents

Abstract

The invention can be used in the power supply circuits of various electronic equipment. The purpose of the invention is to simplify the device. The converter contains a mains rectifier 3, a power amplifier 4 with a transformer 5, a wired generator 6. The device includes pulse distributor 11, sawtooth voltage generators 7 and 8, and comparators 9 and 10. Connecting the outputs of pulse distributor 11 to the inputs of additional power amplifiers 12, 13 with transformers 14, 15, the secondary windings of which are connected via rectifier 16 and filter 17 to output terminals 18 via error signal amplifier 19, provides for reducing the size of the converter by decreasing the number of elements while improving the quality of the output voltage. 3 3.p. f-ly, 3 ill. (L with O1

Description

113

The invention relates to converter equipment, in particular, to sources of secondary power supply of automation and communication systems and can be used to convert a variable voltage of an industrial network into a constant voltage,

The aim of the invention is to simplify the device by reducing the number of semiconductor elements in the cells.

FIG. 1 shows the electrical circuit of the converter; FIG. 2 is one of the embodiments of the pulse distributor; in fig. H - timing diagrams of the main nodes of the scheme.

The converter contains input terminals 1 and 2, through a mains rectifier 3 connected to the main cell of converter 4 with a transformer 5. The control inputs of the power amplifier are connected to the first output of the master oscillator 6, the second output of which is through voltage generators 7 and 8 and comparators 9 and 10, and the third output is directly connected to the inputs of the pulse distributor 11, the outputs connected to the inputs of additional conversion cells 12 and 13 with transformers 14 and 15. Secondary transformer windings 5, 14 and 15 are connected in series and an output connected to the input of the rectifier 16, a filter 17 connected to, the output terminal 18. The output terminals through error amplifier 19 with integrated reference voltage source connected to the second inputs of komparato trench 9 and 10.

The pulse distributor (Fig. 2) includes a counting trigger 20, the outputs of which are connected to four selectors 21-24, the second inputs of which are the control inputs of the pulse distributor and the outputs the outputs of the pulse distributor.

The device works as follows.

When applying the alternating voltage of the primary network to the input terminals 1 and 2 of the converter, it rectifies with the rectifier 3 (Diag5) amma A, fig. 3): n is supplied to the cell 4, assembled according to a half-bridge circuit and converts the input voltage into a sequence of two-pole pulses arriving at the transformer 5.

O

five

0

51

- 0

five

0

five

five

0

72

At the same time, the capacity of the half-bridge power amplifier eliminates the failure of the input voltage to zero. Cell 4 is controlled from the outputs of master oscillator 6 by two sequences of 180 pulses shifted galvanically from each other, one of which is shown in diagram B (Fig. 3).

The pulses of the master oscillator also arrive at the sawtooth voltage generators 7 and B, at the output of which two sawtooth voltage (GPN7 and GPN8) are formed, shown on the diagram B in Hbte (FIG. 3).

The sawtooth voltage is supplied to the first inputs of the comparators 9 and 10, to the second inputs: which is supplied by the voltage obtained by amplifying the error signal between the output voltage and the voltage of the reference source included in the error signal amplifier 19. Output voltage of the comparator 10 (diagram G, fig, C) through pulse distributor 11 is fed to an additional conversion cell 12 with transformer 14, and the output voltage of comparator 9 (diagram D, Fig. H) is fed to distributor 11 through A cell 13 with a transformer 15. The pulse distributor 11 carries out the distribution of pulses between the inputs of cells 2 and 13 in order to ensure their operation in a two-stroke mode.

At the input of the output rectifier 16, the output voltages of the secondary transformer windings are summed: 5, 14, and 15, and the phasing of the transformers 14 and 15 is performed so that the output voltage of the transformer 14 is summed up, and the voltage of the transformer 15 is subtracted from the voltage Transformer 5.

The voltages on the secondary windings of the | Transformers are selected as follows. The average rectified output voltage of the transformer 5 at the nominal value of the input voltage of the converter should be equal to the nominal value of the output voltage. The transformer ratio of transformers 14 and 15 should compensate for the deviation of the output voltage relative to the average value for any given change in the supply voltage. Output

313

the rectifier voltage is depicted in diagram E (Fig. 3). The rectified voltage, smoothed by the filter 17, goes to the output terminals 18.

Cells 12 and 13 are calculated only for a fraction of the output power, so low-power key elements can be used in them. Turning on their power circuits can be made both to the output of the rectifier 3 and to the output terminals 18. In the latter case, the cells 12 and 13 receive a stabilized supply voltage and it becomes possible to use low-voltage high-frequency transistors, which reduces losses of them. The disadvantage of this variant is the need to calculate the transformer 5 for the full output power of the converter. In the first case, the required power of the transformer 5 is obtained less, but the use of high-voltage transistors is necessary.

The use of such a technical solution in converters reduces the number of power transistors to six, which reduces the size of the converter, simplifies it, and improves the quality of the output voltage.

Claims (4)

1. AC to DC converter containing input terminals, through a mains rectifier connected to the main cell conversion with an output transformer, the control inputs of which are connected to the first output of the master oscillator, and two additional cells conversion from the output 174 By transformers, the secondary windings of all transformers are connected in series and through a rectifier and filter are connected to the output terminals and to the input of an error signal amplifier, which is different from the fact that, in order to simplify the device by reducing the number of semiconductor elements, a 5 impulses J are two sawtooth voltage generators and two comparators, the first inputs of which are connected to the second output of the driving oscillator through the sawtooth voltage generators, the second inputs to the output of the error signal amplifier, and the outputs to the control inputs of the pulse distributor, the clock input of which is connected to the third output of the master oscillator, and the outputs to the inputs of additional conversion cells. 2. The converter according to claim 1, characterized in that the power inputs of the additional cells are connected to the output of the network rectifier .. 3. A converter according to claim 1, characterized in that the power inputs of the additional cells are connected to the output terminals. 4. The converter according to claim 1, characterized in that four selectors and a counting trigger are inputted to the pulse distributor, the input of which is connected to the third output of the master oscillator, and the outputs to the corresponding first inputs of the selectors, the second inputs of which are connected to the outputs of the comparators 5 a exits - with inputs of additional cells. From 6 Oto OtE to 12.k. 7J Fie.2 ppppppppppppp SHNCHCH 1111 rrflll Editor A. Gulko Fig.Z Compiled by And, Voitovich Tehred V. Kadar Order 1638/52 Circulation 661 Subscription VNIIPI USSR State Committee for tzobreteniya and discoveries P3035, Moscow, Zh-35, Raushsk nab. d. 4/5  - - - - - - - .- - -.-..-.- „“ Production and printing company, Uzhgorod, st. Project, 4 Proofreader L, Pilipenko