INVESTIGATION OF THE CIRCUIT OF THE VOLTAGE MULTIPLIER OF AN ELECTRONIC INSTALLATION WITH A FREQUENCY OF 5-6 KHZ

ABSTRACT

Until recently, the voltage multiplier was not evaluated properly. Many developers have already considered these schemes from the point of view of lamp technologies and therefore miss incredible opportunities. We are all well aware that the optimal solution was the use of three- and four-fold voltage meters in televisions. In our opinion, we do not need to solve the problems associated with X-rays in a pulsed power supply (PDA), however, as soon as the voltage multiplier circuit reaches a clear limit of simple methods that often use high-frequency switching and remove transformers operating at 60 Hz, the voltage multiplier circuit can be useful for further size reduction. In some cases, a voltage multiplier can provide an excellent way to obtain additional output voltage using the secondary winding of the transformer.

The article provides an overview and technical characteristics of multipliers in modern electronic devices. In addition, when calculating the multiplier, its main parameters are indicated: output voltage, output power, input alternating voltage, required dimensions, operating conditions (temperature, humidity).

АННОТАЦИЯ

До недавнего времени множитель напряжения не оценивался должным образом. Многие разработчики уже рассматривали эти схемы с точки зрения ламповых технологий и поэтому упускают невероятные возможности. Всем нам хорошо известно, что оптимальным решением стало использование трех-и четырехкратных счетчиков напряжения в телевизорах. По нашему мнению, нам не нужно решать проблемы, связанные с рентгеновскими излучениями в импульсном источнике питания (ИИП), однако, как только схема умножителя напряжения достигает четкого предела простых методов, которые часто используют высокочастотную коммутацию и удаляют трансформаторы, работающие на 60 Гц, схема умножителя напряжения может быть полезна для дальнейшего уменьшения размеров. В некоторых случаях множитель напряжения может обеспечить отличный способ получения дополнительного выходного напряжения с использованием вторичной обмотки трансформатора.

В статье представлен обзор и технические характеристики множителей в современных электронных устройствах. Кроме того, при расчете умножителя указываются его основные параметры: выходное напряжение, выходная мощность, входное переменное напряжение, требуемые габариты, условия эксплуатации (температура, влажность).

Keywords: electrical circuit, voltage multipliers, capacitors, output voltage, input voltage, transformer, voltage stability, etc.

Ключевые слова: электрическая схема, умножители напряжения, конденсаторы, выходное напряжение, входное напряжение, трансформатор, стабильность напряжения и др.

Introduction

What if you charge the capacitors in parallel or in turn, and then connect them in series and use the resulting battery as a higher voltage source? But this is a well–known method of increasing voltage, called multiplication.

Using a voltage multiplier, it is possible to obtain a higher voltage from a low voltage source without having to resort to a step-up transformer for this purpose. In some applications, the transformer will not work at all, and sometimes it is much more convenient to use a multiplier to increase the voltage.

To date, in order to ensure optimal performance of the specified functions, current electronic devices must have high efficiency and reliability. Also, for most electronic devices, the main requirements are reduced to the following: small weight and size indicators and low cost. The sharp rise in the price of copper wire

used for winding transformers provoked the search for other ways to increase the voltage. In this regard, the use of voltage multiplier circuits has become the most relevant.

1. Voltage multipliers

Voltage multipliers are special rectification circuits in which the output voltage is the value of the peak alternating input voltage increased by an integer number of times (depends on the number of cascades used). This scheme allows you to increase the voltage without using a step-up transformer.

All multipliers are divided into symmetric and non-symmetric circuits. Their difference is that symmetrical multiplication circuits will have twice the frequency of ripples of the rectified output voltage at the output. A symmetrical circuit is a connection of two asymmetric circuits, one of which has reversed the polarity of capacitors and the conductivity of diodes.

Asymmetric voltage circuits are divided into: multiplication circuits of the I-th kind (parallel) and multiplication circuits of the II-th kind (sequential) [2].

1.1 Voltage doubler

Doubler schemes are the simplest of all multipliers (Fig. 1). You can build an unsymmetric (one-half-period) or symmetrical (two-half-period) scheme. It is impossible to attribute the doubler to the I-th or II-th genus [1].

Figure 1. On the left – a symmetrical two–half-period doubler, on the right - a one-half-period carrier

A single–period doubler is an independent scheme or part of multi-stage multiplication schemes.

A two–half-period doubler is two circuits of a single-half-period single-phase rectifier connected in series. With a positive half-wave of the input AC voltage, the upper rectifier operates, charging the upper capacitor to the peak value of the input voltage (not counting the voltage drop on the diode). With a negative half-wave, the lower capacitor is charged to the same value. At the output, the capacitors will give the sum of the voltage [4].

1.2 Voltage Tripler

Voltage triples can be of the 1st or 2nd kind (Fig.2), but they cannot be symmetrical, like any schemes with odd multiplication multiplicity [1]. Such a voltage multiplier is built by connecting a voltage doubler and another single-phase single-period voltage rectifier.

Figure 2. On the left – a voltage multiplier of the first kind, on the right – of the second kind

By analogy with doublers: a single-half-period rectification circuit charges its capacitor to the peak value of the input AC voltage. As a result, the output provides the sum of the output voltage from the doubler and from the additional rectifier, which gives a tripled value of the input voltage [5].

1.3 Voltage quadrupler

This multiplication circuit is a combination of two voltage doublers. Each doubler provides twice the voltage at its outputs. With a serial connection of such doublers and the supply of an alternating input voltage: at the output we get a constant voltage increased by 4 [1].

Figure3. On the left – the I–th kind of accountant, on the right - the II-th kind

The principle of operation for voltage quadruplers of the 1st and 2nd kind (Fig. 3) does not differ from other multiplication schemes: capacitors connected to point 1, in the other half-cycle - connected to point 2 [6].

2. Calculation of parameters of voltage multipliers

Calculation of parameters for asymmetric schemes of the I-th kind:

If two identical capacitors, one of which is fully charged and the other is discharged, are connected in parallel, a redistribution of electrical energy will occur: a fully charged capacitor will give its energy to the discharged one until the voltage equalizes between them [8].

Figure 4. The scheme of an asymmetric multiplier of the I-th kind

The capacitor charged to its maximum capacity will begin to give its energy to the next capacitor: the voltage on C1 will begin to decrease, and on C2 - to increase. C3, charging from C2, will receive an even smaller charge. That is, for the best operation of the voltage multiplier circuit, the first capacitor should have the maximum capacity, and the last one should have the minimum, so that each capacitor could charge each subsequent one more with its large capacity [7].

The minimum capacitance of the capacitor at the output C (N) is calculated by the formula (1), based on the set level of ripples of the rectified voltage K_П (selected within 0.5-3.0%) and the load resistance R_H

                                                        (1)

The capacitances of the remaining capacitors that ensure the best operation of the circuit will be determined by the formula (2)

                                             (2)

where C(n) - is the capacitance of a particular capacitor, C(N) - is the capacitance of the capacitor at the output of the circuit, M - is the capacitance increase coefficient determined by Table 1[4] .

Table 1.

Coefficient values

Calculation of parameters for asymmetric circuits of the second kind:

In this circuit, all capacitors, except C1, are charged to twice the amplitude voltage, and an amplitude voltage is applied from 1. Thus, the operating voltage of capacitors and diodes turns out to be quite low [1].

The required capacitance of the capacitors in this circuit is determined by the approximate formula.

                                                             (3)

where N - is the multiplication factor of the voltage; K_П is the permissible ripple coefficient of the output voltage, %; R_H is the load resistance, kOm [8].

Figure 5. Diagram of an asymmetric multiplier of the II-th kind

Conclusion

In this research paper, I made an overview of the purpose, structure and load of voltage multipliers. Considered the advantages and disadvantages of voltage multipliers, the principle of operation. Circuits of voltage doubling circuits, and considered calculation formulas. Advantages of voltage doubling circuits: to obtain the same rectified voltage, half the number of turns of the secondary winding of the transformer is required compared to the bridge circuit, and the fact that the midpoint is four times smaller than in two half-wave circuits with an output, I considered that the reverse voltage of the valve is equal to the rectified voltage, and there is no magnetization of the transformer.

References:

1. Khrechkov N. G. "Dynamic characteristics of voltage multipliers of high-voltage electrical systems", Saratov, 2006.- 208 p.: ill. RGB OD, 61 06-5/2782
2. https://all-audio.pro/c35/spravochniki/umnozhitel-napryazheniya-visokovoltniy.php
3. https://radioskot.ru/publ/bp/umnozhitel_naprjazhenija/7-1-0-363
4. N. Filenko. Principles of construction and operation of voltage multiplication schemes
5. B. Grabowski. Handbook of electronics / B. Grabovsky-2nd ed., ISPR. - M.: DMK-Press, 2009-p. 286
6. Schreiber, G. 300 power supply circuits. Rectifiers. Switching power supply. Linear stabilizers and converters / G. Schreiber. - M.: DMK-Press, 2008-p. 8
7. Sh.A.Bakhtaev, G.K.Syzdykova, A.J. Toigozhinova, K.Kojabergenova. "Corona discharge on microelectrodes”. Almaty 2017, 212c.
8. http://www.radiomexanik.spb.ru/9.-analiz-tsepey-postoyannogo-toka/9.-teorema-tevenina.html