JPS6277059A - Voltage multiplier - Google Patents

Abstract

PURPOSE:To shorten the rising time of an output voltage by forming a part of diodes of a multiplier for multiplying a voltage by a series circuit of a plurality of diodes and a plurality of capacitors of a bridge circuit to reduce a ripple. CONSTITUTION:Reverse phase AC terminals (a), (b) and a ground terminal (c) are provided at the secondary side of a transformer T. Capacitors C1-C3 and C4, C5, Ca are connected in series with the terminals (a), (b). Diodes D1-D6 having equal rectifying directions are connected in series with the terminal (c). Capacitors C6, C7 are connected in series, and the connecting pints of the capacitors C1-C7 and Ca are connected with the connecting points (d)-(h) of the diodes D1-D6. Further, a bridge circuit having diodes D7, D8, Da, Db and a capacitor C8 is connected between the capacitors C3, C7 and Ca, and a load R is connected between an output terminal (k) and a ground. Thus, the rising time of the output voltage is shortened, the ripple of the output is reduced, and a voltage drop due to a load current can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a voltage multiplier circuit that is constructed by combining a plurality of diodes and capacitors and generates a high voltage by rectifying and multiplying an AC input.

[Technical background of the invention and its problems] Various voltage multiplier circuits have been considered in the past that combine a large number of diodes and capacitors and generate high voltage by rectifying and multiplying AC input. FIG. 5 shows an example of its configuration.

In FIG. 5, T is a transformer, and this transformer T
An AC power source A is connected to the primary winding n1. The secondary winding n2 of this transformer T is provided with a center tap. Here, the terminals on both sides of the secondary winding n2 and the center tap are defined as first to third input terminals a, b, and c, respectively. still,
The third input terminal C is grounded. Furthermore, a diode circuit in which a plurality of WA (eight in this case) diodes D1 to D8 are connected in series so that the rectification directions are the same is connected between the third input terminal C and the output terminal. Ru.

That is, the anode of the diode D1 is connected to the third input terminal C.
and the cathode of diode D8 is connected to the output terminal k.
8th class. Here, each diode connection point of the diode circuit is designated as d to j.

The first input terminal a and the diode [)7. A first capacitor circuit in which capacitors C1 to C3 are directly connected to the connection point j of [)8 is connected.

And capacitors C1, C2, C3 are respectively a-d
, d-g, and g-j. The second input terminal has a diode D13. A second capacitor circuit in which capacitors C4 and C5 are connected in series is connected between D7 and connection point 1. Capacitors C4 and C5 are connected between b-3f-*, respectively. A third capacitor circuit having capacitors 06 to C8 connected in series is connected between the third input tHc and the output terminal. And capacitors C6, C7, and C8 are ce, eh, and h, respectively.
– is connected between. Note that the output end is grounded via a load R.

In a voltage multiplier circuit having such a configuration, for example, a square wave AC voltage from an AC power supply A is applied to the primary winding n1 of the transformer T, and a voltage is applied between the first and second input terminals a and b of the secondary winding n2. If voltages of ±2EV are generated alternately in the diode circuit, each capacitor C1 to
The voltage obtained by adding the voltage generated between a and 0, b and c, or a and b of the transformer T to the charging voltage of C5 is charged to capacitors C6 to C8 of the third capacitor circuit, resulting in a voltage of 10 EV. It is capable of generating voltage.

This configuration has the advantage that the multiplication factor is high and that the withstand voltage required for the transformer T can be significantly reduced.

Furthermore, in order to reduce the output ripple, there is also a double-wave rectification type voltage multiplier circuit as shown in FIG.

This circuit is generally referred to as a double-wave rectified Kotscroft-Walton circuit. In FIG. 6, the same parts as in FIG. 5 are designated by the same reference numerals.

In FIG. 6, first to third capacitor circuits each having a plurality of (five in this case) capacitors connected in series are connected to the first to third input terminals a to C, respectively. . Here, connect the connection points between each capacitor C11 to C15 of the first capacitor circuit to d in order from the input end side.
~Q, and roughly assume that the terminal end of the capacitor C15 is h.

In addition, each capacitor 016 to 0 of the second capacitor circuit
The connection points between the capacitors C20 and C20 are designated as i-2 in order from the input end side, and the terminal end of the capacitor C20 is roughly designated as m. Further, the connection points between the capacitors C21 to C25 of the third capacitor circuit are set as n-Q in order from the input end side, and
Let the end of 5 be r. Each of the above capacitors C11 to C25
Diodes [)11 to D14 are bridge-connected between C-d-n-i-0 for each connection point of ni-0, ri-
Diodes [)15 to [)18, []19 to [)22] are connected between Q-q-coup and q-hr-m-q, respectively.
D23 to D26 and D27 to [)30 are bridge-connected. A load R is connected between the output end and ground.

In a voltage transmitting circuit with such a configuration, when all capacitors have the same capacitance jiC[F], the following design calculation formula is known for calculating the output voltage of the circuit, which is described in various documents and is It has been put into practical use.

Eout = 2nEin - (upper n3 yo 2 upper ■ + 4 n + 12 n')
--・111f However・[:Out: Output voltage [VI Ein; Input voltage [Vl n ; Number of multiplication stages I; Load current [△IC; Capacity of unit capacitor [F] f : Input frequency [Hzl] On the other hand, converter technology Due to the development of AC power supplies, the operating frequency of AC power supplies is becoming higher and higher every year. For this reason, a high frequency power supply can now be used as an input to the voltage multiplier circuit as described above, and the usefulness of this circuit is increasing.

Therefore, the technical requirements for this voltage multiplier circuit are becoming more sophisticated, but this type of voltage multiplier circuit not only has a relatively high equivalent internal impedance and also requires a considerable amount of time for the generated voltage to rise. There are problems such as large output ripple and large voltage drop due to load current, and it is desired that these problems be resolved as soon as possible.

[Objective of the Invention] This invention was made in consideration of the above circumstances, and provides an extremely high-performance voltage multiplier circuit that has a short output voltage rise time, small output ripple, and little voltage drop due to load current. The purpose is to provide

[Summary of the Invention 1 That is, the voltage multiplier circuit according to the present invention can be applied to any '!
First and second alternating current sources connected to the potential point and generating equal voltages of mutually opposite phases with respect to the potential point, and a plurality of diodes are connected in series so that the rectification direction is the same, and one end is connected to the A diode circuit that is connected to a potential point and the other end is connected to an output end, and at least one capacitor is connected in parallel to both ends of this diode circuit as an output capacitor, and this output capacitor is composed of multiple capacitors. is a first capacitor circuit in which the connection point between the capacitors is connected to the connection point between the first diodes of the diode circuit, and one of the plurality of series capacitors in which a plurality of capacitors are connected in series. 'atIi capacitors are connected in series with a second capacitor circuit having one end connected to the output end of the first alternating current source and the other end connected to the connection point between the second diodes of the diode circuit. , and one end of the plurality of series capacitors is connected to the second AC'? a third capacitor circuit connected to the output end of the PL source and the other end connected to the connection point between the third diodes of the diode circuit, the outputs of the first and second AC sources; In the device that rectifies and multiplies a voltage to generate a high voltage at the output terminal connected to the other end of the first capacitor circuit, four diodes are bridged for any output capacitor of the first capacitor circuit. At least one set of bridge type rectifier circuits are incorporated in which the two input terminals of the diode bridge circuit are connected to arbitrary capacitors of the second and third capacitor circuits, respectively. It is.

[Embodiment J of the Invention An embodiment of the present invention will be described below with reference to FIG. 1. However, in FIG. 1, the same parts as in FIG. 5 are designated by the same reference numerals, and only the different parts are labeled here.

FIG. 1 shows the configuration of the diode D7. of the diode circuit. A series circuit of diodes Da and Db is connected in parallel to D8. Here, the diode [)
Let the connection point of a, [)b be 2.

On the other hand, each capacitor C1~ of the first capacitor circuit
C3 is connected between a-e, eh, h-j, respectively,
Each capacitor C4, C5, Ca of the second capacitor circuit
are b-d and d-Q, respectively.

The capacitors C6 to C8 of the third capacitor circuit are connected between Cf and fi, respectively.

i-.

That is, in the above configuration, the diode D7°Da
, Da, and Db constitute a diode bridge rectifier circuit with j and Q as input terminals and i and k as output terminals, and the fifth
While the circuit shown in the figure includes a half-wave rectifier element, the circuit with the above configuration has a full-wave rectifier circuit.

Therefore, when the voltage transmitting circuit configured as described above was compared with the circuits shown in FIGS. 5 and 6, it was found that it exhibited the following excellent effects. A specific example will be described below.

First, 4000 [V] is applied between the first and third input terminals 1a and 0 and between the second and third input terminals b and c of each circuit.
Assume that a symmetrical square wave voltage with a voltage drop width of
We investigated the output voltage under load, voltage drop, ripple voltage, rise time (time to reach 90% of the constant voltage in the load chamber), number of capacitors, and number of diodes for each circuit when obtaining [KV], and found the following. as shown in the table below.

As is clear from the table above, in the voltage multiplier circuit with the above configuration, compared to the conventional circuit shown in FIG.
Even though the rise time is almost the same, the voltage drop is improved by 15% and the ripple voltage is also improved by 50%. Roughly speaking, the number of circuit components is only increased by one capacitor and two diodes. Furthermore, even when compared with the double-wave rectifier Kotscroft-Walton circuit shown in Figure 6, which is representative of a circuit with a small ripple voltage, the conventional amount also shows that the ripple voltage at no-load output is 1.
0% improvement. Furthermore, the voltage drop has also been improved by about 35%. Moreover, the rise time is about half that,
Moreover, the number of component parts is less than half.

Therefore, the voltage multiplier circuit configured as described above has extremely excellent output characteristics such as low voltage drop, low ripple voltage, and short rise time.
Moreover, it has the advantage that there is no need to increase the number of parts so much.

Note that this invention is not limited to the above embodiments,
It may be configured as shown in FIGS. 2 to 4, respectively. In FIGS. 2 to 4, the same parts as in FIG. 1 are designated by the same reference numerals, and their explanations will be omitted.

First, the voltage multiplier circuit shown in FIG.
, Qd are connected in parallel.

Here, the connection point between the diodes Dc and Dd is assumed to be m.

On the other hand, each capacitor C1~ of the first capacitor circuit
C3 is connected between a-d, d-Q, and Q-3, respectively,
Each capacitor C4, C5, Ca of the second capacitor circuit
are connected between b-x, /2-f, f-, respectively,
Each capacitor C6-C8 of the third capacitor circuit is c-e, respectively.

It is connected between eh and h-. That is, the diodes DI, D2, Dc, and Dd constitute a diode bridge rectifier circuit in which d and m are input terminals, and c and e are output terminals.

Next, the voltage multiplier circuit shown in FIG. 3 includes the diode [)4. [)5 has a diode [)e
, [B series circuits are connected in parallel.

Here, the connection point between the diodes De and Of is assumed to be n.

On the other hand, each capacitor C1~ of the first capacitor circuit
C3 is connected between a-e, e-Q, and Q-3, respectively,
Each capacitor C4, C5, Ca of the second capacitor circuit
are connected between b-d, d-n, and n-i, respectively, and the third
Each of the capacitors C6 to C8 of the capacitor circuit is cf.

It is connected between f-h and h-. That is, the diode D4. D5. [) A diode bridge rectifier circuit is constructed in which e, Dfl, tQ, and n are input terminals, and f, h are output terminals.

The voltage multiplier circuit shown in FIG. 4 is a combination of the circuit configuration shown in FIG. 1 and the circuit configuration shown in FIG. A series circuit of diodes Qa and [)b is connected in parallel to [)8, and a diode [)c is connected to diode [)1 and [)2].
, [)d series circuits are connected in parallel. Here, the connection point between diodes Da and Db is assumed to be 2, and the connection point between diodes Dc and Dd is assumed to be m. On the other hand, the first
The capacitors C1 to C3 of the capacitor circuit are a-d and d-Q, respectively.

The capacitors C4, C5, Ca, and Cb of the second capacitor circuit are connected between b-m and m-3, respectively.
The capacitors C6 to C8 of the third capacitor circuit are connected between C-e and e, respectively.
-i, connected between i-. That is,
The above diode [)7. Da, Da, [)b is J, 2 is the input terminal, 1. A diode bridge rectifier circuit is constructed with k as the output terminal, and the diodes DI, D2, Dc
, Dd constitute a diode bridge rectifier circuit with d and mG input terminals, and C and e as output terminals.

That is, the voltage multiplier circuit of FIG. 2 has a diode bridge rectifier circuit in the input stage, and the voltage multiplier circuit of FIG. 3 has a diode bridge rectifier circuit in the intermediate stage. Although these circuits have inferior characteristics compared to the circuit shown in Figure 1, which has a diode bridge rectifier circuit in the output stage, they have lower ripple voltage and voltage than the conventional circuit shown in Figure 5. A certain effect can be obtained in terms of reducing the descent. Furthermore, the voltage multiplier circuit shown in Figure 4 is a combination of the circuit configurations shown in Figures 1 and 2, and has diode bridge rectifier circuits in the input and output stages. , which has very high performance characteristics. Each data of this circuit is shown in the above figure. Even considering that this circuit has a slightly larger number of components and requires one capacitor with a slightly higher withstand voltage,
This can be said to be an extremely effective circuit configuration depending on the purpose of use.

In addition, various modifications can be made without departing from the gist of the invention.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to provide an extremely high-performance voltage multiplier circuit in which the rise time of the output voltage is short, the output ripple is small, and the voltage drop due to load current is small. can.

[Brief explanation of drawings]

FIG. 1 is a circuit configuration diagram showing an embodiment of a voltage multiplier circuit according to the present invention, FIGS. Each figure is a circuit diagram showing the configuration of a conventional voltage multiplier circuit. A...AC power supply, T...transformer, nl...-secondary winding, n2...secondary winding, D1~[)8. [)11～
D30...diode, c1~ca, c11~c2
s, ca - cr , . Capacitor, R...Load.

Claims (1)

[Claims] First and second alternating current sources that are connected to an arbitrary potential point and generate voltages of opposite phase to each other with respect to the potential point, and a plurality of diodes are connected in series so that the rectification direction is the same, and one end is connected to the other. A diode circuit connected to the potential point and the other end connected to the output end, and at least one capacitor connected in parallel to both ends of this diode circuit as an output capacitor, and this output capacitor is composed of a plurality of capacitors. A first capacitor circuit in which the connection points between the capacitors are connected to the connection points between the first diodes of the diode circuit, and a plurality of series capacitors in which a plurality of capacitors are connected in series. A second capacitor circuit having one end connected to the output end of the first alternating current source and the other end connected to the connection point between the second diodes of the diode circuit, and a plurality of capacitors connected in series. a plurality of series capacitors, one end of which is connected to the output end of the second alternating current source, and the other end of which is connected to a connection point between the third diodes of the diode circuit; a capacitor circuit, the voltage multiplier circuit rectifies and multiplies the output voltages of the first and second AC sources to generate a high voltage at an output terminal connected to the other end of the first capacitor circuit, Four diodes are bridge-connected to any output capacitor of the first capacitor circuit, and the two input ends of this diode bridge circuit are connected to any capacitors of the second and third capacitor circuits, respectively. 1. A voltage multiplier circuit incorporating at least one set of bridge type rectifier circuits.