Boost rectification circuit

Abstract

A boost rectification circuit 1 comprises: a transformer 21 that inputs an AC voltage to a primary winding 21a; a full-wave rectification circuit unit 3 that generates a first DC voltage VDC1 by rectifying an AC voltage generated in a secondary winding 21b; a first half-wave rectification-type CW circuit unit 7; and a second half-wave rectification-type CW circuit unit 8. The first half-wave rectification-type CW circuit unit 7 rectifies and boosts the AC voltage generated in the secondary winding 21b. The second half-wave rectification-type CW circuit unit 8 rectifies and boosts the AC voltage generated in the secondary winding 21b with a phase opposite to that of the first half-wave rectification-type CW circuit unit 7. An output voltage from the first half-wave rectification-type CW circuit unit 7 and an output voltage from the second half-wave rectification-type CW circuit unit 8 are added to the first DC voltage VDC1 in a first series circuit unit 4 to generate a second DC voltage VDC2.

Description

Boost rectifier circuit

[0001] This disclosure relates to a boost rectifier circuit. This application claims priority under Japanese application No. 2024-168725, filed on 17 September 2024, and incorporates all the provisions of the said Japanese application.

[0002] A boost-rectifier circuit is known that includes a Cockcroft-Walton circuit (hereinafter referred to as a CW circuit) which boosts and rectifies the input voltage by combining multiple stages of circuit sections including capacitors and diodes (see, for example, Patent Document 1). There are two types of CW circuits: half-wave rectification and full-wave rectification.

[0003] Japanese Patent Publication No. 2016-13015

[0004] Half-wave rectification CW circuits generate high voltage using only one half-wave of the AC voltage generated in the secondary winding of the transformer. Half-wave rectification CW circuits have fewer components and a simpler circuit configuration, but they are less efficient than full-wave rectification circuits and are more susceptible to ripple noise and AC noise superimposed on the output voltage. Full-wave rectification CW circuits generate high voltage using both half-waves of the AC voltage generated in the secondary winding of the transformer. Full-wave rectification CW circuits are more efficient than half-wave rectification circuits and are less susceptible to ripple noise and AC noise superimposed on the output voltage, but they have more components and a more complex circuit configuration.

[0005] The purpose of this disclosure is to provide a boost rectifier circuit that has a simple structure and can suppress ripple voltage.

[0006] A step-up rectifier circuit relating to one aspect of the present disclosure includes: [1] a transformer including a primary winding and a secondary winding, to which an AC voltage is input; a full-wave rectifier circuit section connected to the secondary winding and which generates a first DC voltage by rectifying the AC voltage generated in the secondary winding; a first series circuit section consisting of a plurality of first capacitors and a plurality of second capacitors connected alternately in series; a second series circuit section consisting of a plurality of third capacitors connected in series; and a third series circuit section consisting of a plurality of fourth capacitors connected in series, wherein one end of the second series circuit section is connected to one end of the secondary winding, one end of the third series circuit section is connected to the other end of the secondary winding, and one end of the first series circuit section is connected to the output terminal of the full-wave rectifier circuit section. The third capacitor in the series circuit section and the first capacitor in the first series circuit section constitute a first half-wave rectifier type boost circuit section, the fourth capacitor in the third series circuit section and the second capacitor in the first series circuit section constitute a second half-wave rectifier type boost circuit section, the first half-wave rectifier type boost circuit section rectifies and boosts the AC voltage generated in the secondary winding, the second half-wave rectifier type boost circuit section rectifies and boosts the AC voltage generated in the secondary winding in the opposite phase to the first half-wave rectifier type boost circuit section, and the output voltage from the first half-wave rectifier type boost circuit section and the output voltage from the second half-wave rectifier type boost circuit section are added to the first DC voltage in the first series circuit section to generate a second DC voltage, thus creating a boost rectifier circuit.

[0007] In the boost rectifier circuit described in [1] above, by placing the full-wave rectifier circuit immediately after the transformer, it is possible to generate a first DC voltage while suppressing ripple by utilizing both half-waves of the AC voltage generated in the secondary winding of the transformer. Furthermore, in the half-wave rectifier boost circuit, which has fewer components than the full-wave rectifier boost circuit, the phase of the output voltage from the first half-wave rectifier boost circuit and the phase of the output voltage from the second half-wave rectifier boost circuit are in opposite phases, so the noise superimposed on the first series circuit cancels each other out. As a result, it is possible to generate a second DC voltage while effectively suppressing ripple. In addition, the boost rectifier circuit described in [1] does not require the use of two transformers or a transformer with a center tap, as is the case with the full-wave rectifier boost circuit. Therefore, by combining the full-wave rectifier circuit and the half-wave rectifier CW circuit, a simple structure is achieved while suppressing ripple voltage.

[0008] A boost rectifier circuit relating to one aspect of the present disclosure includes: [2] "The full-wave rectifier circuit section includes a first rectifier capacitor, a second rectifier capacitor, a third rectifier capacitor, a first diode, a second diode, a third diode, and a fourth diode, wherein the anode of the first diode is connected to one electrode of the first rectifier capacitor, the cathode of the first diode is connected to one electrode of the second rectifier capacitor, the anode of the second diode is connected to one electrode of the second rectifier capacitor, the cathode of the second diode is connected to one end of the secondary winding, and the third diode The anode of the diode is connected to one electrode of the first rectifier capacitor, the cathode of the third diode is connected to one electrode of the third rectifier capacitor, the anode of the fourth diode is connected to one electrode of the third rectifier capacitor, the cathode of the fourth diode is connected to the other end of the secondary winding, the other electrode of the first rectifier capacitor is connected to a reference potential line, the other electrode of the second rectifier capacitor is connected to the other end of the secondary winding, and the other electrode of the third rectifier capacitor is connected to one end of the secondary winding, which may be the boost rectifier circuit described in [1]. In this case, the amount of charge stored in the first capacitor is increased by utilizing the positive and negative half-waves of the AC voltage generated in the secondary winding, and the boost ratio can be increased in the full-wave rectifier circuit section.

[0009] A boost rectifier circuit relating to one aspect of the present disclosure includes: [3] "The full-wave rectifier circuit section includes a first rectifier capacitor, a first diode, a second diode, a third diode, and a fourth diode, wherein the anode of the first diode is connected to one electrode of the first rectifier capacitor, the cathode of the first diode is connected to one end of the secondary winding, the anode of the second diode is connected to one end of the secondary winding, and the cathode of the second diode is connected to the first rectifier The boost rectifier circuit described in [1] may be the one in which the other electrode of the capacitor is connected, the anode of the third diode is connected to one electrode of the first rectifier capacitor, the cathode of the third diode is connected to the other end of the secondary winding, the anode of the fourth diode is connected to the other end of the secondary winding, the cathode of the fourth diode is connected to the other electrode of the first rectifier capacitor, and the other electrode of the first rectifier capacitor is connected to the reference potential line. In this case, the full-wave rectifier circuit section also has a simple configuration with fewer components, making it easier to further reduce the number of components in the boost rectifier circuit.

[0010] A boost rectifier circuit relating to one aspect of the present disclosure may be [4] "the boost rectifier circuit according to [1] or [2], wherein the first half-wave rectifier boost circuit further comprises a plurality of diodes, the cathode of the diode closest to the secondary winding among the plurality of diodes is connected to a node between the third capacitor closest to the secondary winding and the next closest third capacitor among the plurality of third capacitors, and the anode of the diode closest to the secondary winding among the plurality of diodes is connected to the output terminal of the full-wave rectifier circuit." In this case, in the second series circuit, the voltage of the first stage of the second series circuit is divided between the third capacitor closest to the secondary winding and the next closest third capacitor. Therefore, the magnitude of the voltage generated in each third capacitor is reduced.

[0011] A boost rectifier circuit relating to one aspect of this disclosure may be [5] "the boost rectifier circuit according to [1], wherein the full-wave rectifier circuit section includes a plurality of capacitors connected in series with each other, and the plurality of capacitors are connected between a reference potential line and one end of the first series circuit section." In this case, the magnitude of the voltage generated across each capacitor is reduced by the plurality of capacitors connected in series with each other.

[0012] According to this disclosure, it is possible to provide a boost rectifier circuit that has a simple structure and can suppress ripple voltage.

[0013] Figure 1 is a circuit diagram showing the configuration of a boost rectifier circuit according to one embodiment of the present disclosure. Figure 2 is a circuit diagram showing the configuration of a boost rectifier circuit according to a second embodiment. Figure 3 is a circuit diagram showing the configuration of a boost rectifier circuit according to a third embodiment. Figure 4 is a circuit diagram showing the configuration of a boost rectifier circuit according to a first comparative example. Figure 5 is a circuit diagram showing the configuration of a boost rectifier circuit according to a second comparative example. Figure 6(a) is a diagram showing an example of ripple voltage superimposed on the second DC voltage generated by the boost rectifier circuit according to the second embodiment, the boost rectifier circuit according to the first comparative example, and the boost rectifier circuit according to the second comparative example. Figure 6(b) is a diagram showing an example of comparing the ripple voltage, number of components, number of transformers, and output voltage rise time for the boost rectifier circuit according to the second embodiment, the boost rectifier circuit according to the first comparative example, and the boost rectifier circuit according to the second comparative example. Figure 7 is a circuit diagram showing the configuration of a boost rectifier circuit according to a first modified example. Figure 8 is a circuit diagram showing the configuration of a boost rectifier circuit according to a second modified example.

[0014] Hereinafter, preferred embodiments of a boost rectifier circuit according to one embodiment of the present disclosure will be described in detail with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant descriptions are omitted.

[0015] [First Embodiment] Figure 1 is a circuit diagram showing the configuration of a boost rectifier circuit according to one embodiment of the present disclosure. As shown in Figure 1, the boost rectifier circuit 1 according to this embodiment includes a DC power supply 11, an H-bridge circuit 12, a transformer 21, a diode 22, a diode 23, a full-wave rectifier circuit section 3, a first series circuit section 4, a second series circuit section 5, and a third series circuit section 6.

[0016] The DC power supply 11 outputs a DC voltage. One end of the DC power supply 11 is connected to the reference potential line (also called the ground potential line or earth potential line) GND, and the other end is connected to the input terminal of the H-bridge circuit 12. One output terminal 12a of the H-bridge circuit 12 is connected to one end of the primary winding 21a of the transformer 21 via a resistor 13a, a capacitor 14a, and an inductor 15a. The other output terminal 12b of the H-bridge circuit 12 is connected to the other end of the primary winding 21a of the transformer 21. The two ends of the primary winding 21a are connected to each other via an inductor 15b and a capacitor 14b, which are provided in parallel with each other.

[0017] In the circuit described above, when a DC voltage is output from the DC power supply 11, this DC voltage is periodically distributed to two output terminals 12a and 12b by the H-bridge circuit 12. That is, square waves with opposite phases are output from the two output terminals 12a and 12b. These square waves are converted into AC voltage by the resistor, inductor, and capacitor described above, and this AC voltage is input to the primary winding 21a of the transformer 21. Note that other circuits (such as a push-pull circuit) may be used instead of the H-bridge circuit 12, as long as they can apply an AC voltage to the primary winding 21a of the transformer 21.

[0018] The anode of diode 22 is connected to one end 21c of the secondary winding 21b. The cathode of diode 22 is connected to the reference potential line GND. The anode of diode 23 is connected to the other end 21d of the secondary winding 21b. The cathode of diode 23 is connected to the reference potential line GND.

[0019] The full-wave rectifier circuit section 3 is connected to both ends of the secondary winding 21b. The full-wave rectifier circuit section 3 includes a capacitor 31 (first rectifier capacitor), a capacitor 32 (second rectifier capacitor), a capacitor 33 (third rectifier capacitor), a diode 34 (first diode), a diode 35 (second diode), a diode 36 (third diode), and a diode 37 (fourth diode). In the following description, one electrode of a capacitor mainly refers to the electrode located on the output side, i.e., the side opposite to the secondary winding 21b. The other electrode of a capacitor mainly refers to the electrode located on the input side, i.e., the side opposite to the secondary winding 21b.

[0020] The anode of diode 34 is connected to one electrode of capacitor 31, and the cathode of diode 34 is connected to one electrode of capacitor 32. The anode of diode 35 is connected to one electrode of capacitor 32, and the cathode of diode 35 is connected to one end 21c of the secondary winding 21b. The anode of diode 36 is connected to one electrode of capacitor 31, and the cathode of diode 36 is connected to one electrode of capacitor 33. The anode of diode 37 is connected to one electrode of capacitor 33, and the cathode of diode 37 is connected to the other end 21d of the secondary winding 21b. The other electrode of capacitor 31 is connected to the reference potential line GND. The other electrode of capacitor 32 is connected to the other end 21d of the secondary winding 21b. The other electrode of capacitor 33 is connected to one end 21c of the secondary winding 21b.

[0021] The full-wave rectifier circuit 3 generates a first DC voltage VDC1 by rectifying the AC voltage generated in the secondary winding 21b. In the full-wave rectifier circuit 3 according to this embodiment, the first DC voltage VDC1 obtained by rectifying and boosting the AC voltage in the secondary winding 21b is output from the output terminal of the full-wave rectifier circuit 3, i.e., one electrode of the capacitor 31. The full-wave rectifier circuit 3 generates the first DC voltage VDC1 by, for example, utilizing the positive and negative half-waves of the AC voltage in the secondary winding 21b to increase the amount of charge stored in the capacitor 31. As an example, if the DC power supply 11 generates a voltage of 50V and the winding ratio of the transformer 21 is 1:100, the amplitude value of the AC voltage in the secondary winding 21b may be 5kVp-p. In this case, the full-wave rectifier circuit 3 generates a first DC voltage VDC1 with an absolute value of 10kV.

[0022] The first series circuit section 4 is made up of multiple first capacitors and multiple second capacitors connected alternately in series. In the example in Figure 1, the first series circuit section 4 is made up of N first capacitors Cp(2), Cp(4), ..., Cp(2N) and N second capacitors Cq(2), Cq(4), ..., Cq(2N) connected alternately in series. One end of the first series circuit section 4 is connected to the output terminal of the full-wave rectifier circuit section 3. Specifically, one end of the first series circuit section 4 is connected to one electrode of capacitor 31. The second series circuit section 5 is made up of multiple third capacitors connected in series. In the example in Figure 1, the second series circuit section 5 is made up of N third capacitors Cp(1), Cp(3), ..., Cp(2N-1) connected in series. One end of the second series circuit section 5 is connected to one end 21c of the secondary winding 21b. The third series circuit section 6 is made up of multiple fourth capacitors connected in series. In the example in Figure 1, the third series circuit section 6 is made up of N fourth capacitors Cq(1), Cq(3), ..., Cq(2N-1) connected in series. One end of the third series circuit section 6 is connected to the other end 21d of the secondary winding 21b.

[0023] Then, the anode of diode Dp(n) (where n = 1, 2, 3, ...) is connected to one electrode of capacitor Cp(n), and the cathode of diode Dp(n) is connected to the other electrode of capacitor Cp(n+1). However, the cathode of the final stage diode Dp(2N) is connected to one electrode of capacitor Cp(2N-1). The anode of diode Dq(n) is connected to one electrode of capacitor Cq(n), and the cathode of diode Dq(n) is connected to the other electrode of capacitor Cq(n+1). However, the cathode of the final stage diode Dq(2N) is connected to one electrode of capacitor Cq(2N-1).

[0024] In this embodiment, the third capacitors Cp(1), Cp(3), ..., Cp(2N-1) of the second series circuit section 5 and the first capacitors Cp(2), Cp(4), ..., Cp(2N) of the first series circuit section 4 constitute the first half-wave rectified CW circuit section (first half-wave rectified boost circuit section) 7. The fourth capacitors Cq(1), Cq(3), ..., Cq(2N-1) of the third series circuit section 6 and the second capacitors Cq(2), Cq(4), ..., Cq(2N) of the first series circuit section 4 constitute the second half-wave rectified CW circuit section (second half-wave rectified boost circuit section) 8. The first series circuit section 4 is a common circuit section in the first half-wave rectified CW circuit section 7 and the second half-wave rectified CW circuit section 8.

[0025] The first half-wave rectifier CW circuit section 7 rectifies and boosts the AC voltage generated across the secondary winding 21b. The first half-wave rectifier CW circuit section 7 generates a DC output voltage from the AC voltage by repeatedly accumulating charge in the third capacitors Cp(1), Cp(3), ..., Cp(2N-1) and the first capacitors Cp(2), Cp(4), ..., Cp(2N), and rectifying with the diode Dp(n). The second half-wave rectifier CW circuit section 8 rectifies and boosts the AC voltage generated across the secondary winding 21b in the opposite phase (a phase difference of 180°) to that of the first half-wave rectifier CW circuit section 7. The second half-wave rectifier type CW circuit section 8 generates a DC output voltage from an AC voltage by repeatedly accumulating charge in the fourth capacitors Cq(1), Cq(3), ..., Cq(2N-1) and the second capacitors Cq(2), Cq(4), ..., Cq(2N), and rectifying the charge in the diode Dq(n).

[0026] The output voltages from the first half-wave rectifier CW circuit section 7 and the output voltage from the second half-wave rectifier CW circuit section 8 are added to the first DC voltage VDC1 in the first series circuit section 4 to generate the second DC voltage VDC2. The second DC voltage VDC2 is output from the other end of the first series circuit section 4 as the output voltage of the boost rectifier circuit 1 and supplied to the load RL. More specifically, in the boost rectifier circuit 1, the voltages generated at the electrodes on both ends of the first capacitors Cp(2), Cp(4), ..., Cp(2N) and the second capacitors Cq(2), Cq(4), ..., Cq(2N) in the first series circuit section 4 are added to the first DC voltage VDC1 in sequence to finally generate the second DC voltage VDC2. For example, if the absolute value of the first DC voltage VDC1 is 10kV, a voltage of 5kV is generated at the electrodes across each of the first capacitors Cp(2), Cp(4), ..., Cp(2N) and the second capacitors Cq(2), Cq(4), ..., Cq(2N), resulting in a final absolute value of approximately 40kV for the second DC voltage VDC2.

[0027] [Second Embodiment] Figure 2 is a circuit diagram showing the configuration of a boost rectifier circuit 1A according to the second embodiment of the present disclosure. The boost rectifier circuit 1A differs from the boost rectifier circuit 1 according to the first embodiment in that it is made up of N+1 (where N is an integer of 2 or more; the figure illustrates the case where N=3) third capacitors Cp(1), Cp(3), ..., Cp(2N+1) connected in series, and that 2N+1 diodes Dp(1), Dp(2), ..., Dp(2N+1) connect the first series circuit section 4 and the second series circuit section 5. In the example in Figure 2, the anode of diode Dp(1) is connected to the other electrode of capacitor Cq(2), and the cathode of diode Dp(1) is connected to one electrode of capacitor Cp(1). The anode of diode Dp(2n) (where n = 1, 2, 3, ...) is connected to one electrode of capacitor Cp(2n+1), and the cathode of diode Dp(2n) is connected to the other electrode of capacitor Cp(2n). The anode of diode Dp(2n+1) is connected to one electrode of capacitor Cp(2n), and the cathode of diode Dp(2n+1) is connected to one electrode of capacitor Cp(2n+1).

[0028] In the boost rectifier circuit 1A, the voltage of the first stage of the second series circuit section 5 is divided at the third capacitor Cp(1) and the third capacitor Cp(3) of the second series circuit section 5. As a result, the absolute value of the voltage generated at the third capacitor Cp(1) of the second series circuit section 5 in this embodiment is smaller than the absolute value of the voltage generated at the third capacitor Cp(1) of the second series circuit section 5 in the first embodiment.

[0029] [Third Embodiment] Figure 3 is a circuit diagram showing the configuration of a boost rectifier circuit 1B according to a third embodiment of the present disclosure. The boost rectifier circuit 1B differs from the boost rectifier circuit 1 according to the first embodiment in that it has a full-wave rectifier circuit section 3A instead of a full-wave rectifier circuit section 3. The full-wave rectifier circuit section 3A is connected to both ends of the secondary winding 21b. The full-wave rectifier circuit section 3A includes a capacitor 41 (first rectifier capacitor), a diode 42 (first diode), a diode 43 (second diode), a diode 44 (third diode), and a diode 45 (fourth diode). The anode of diode 42 is connected to one electrode of capacitor 41, and the cathode of diode 42 is connected to one end 21c of the secondary winding 21b. The anode of diode 43 is connected to one end 21c of the secondary winding 21b, and the cathode of diode 43 is connected to the other electrode of capacitor 41. The anode of diode 44 is connected to one electrode of capacitor 41, and the cathode of diode 44 is connected to the other end 21d of the secondary winding 21b. The anode of diode 45 is connected to the other end 21d of the secondary winding 21b, and the cathode of diode 45 is connected to the other electrode of capacitor 41. The other electrode of capacitor 41 is connected to the reference potential line GND.

[0030] The full-wave rectifier circuit 3A generates a first DC voltage VDC1 by rectifying the AC voltage generated in the secondary winding 21b. Unlike the full-wave rectifier circuit 3 of the first embodiment, the full-wave rectifier circuit 3A does not need to boost the AC voltage. In the full-wave rectifier circuit 3A, the positive and negative half-waves of the AC voltage in the secondary winding 21b are rectified by diodes 42 to 45, and the first DC voltage VDC1 is output from one electrode of capacitor 41. As an example, if the DC power supply 11 generates a voltage of 50V and the winding ratio of the transformer 21 is 1:100, the amplitude value of the AC voltage in the secondary winding 21b may be 5kVp-p. In this case, the full-wave rectifier circuit 3A generates a first DC voltage VDC1 with an absolute value of 5kV. Then, in the boost rectifier circuit 1B, the voltages generated at the electrodes across the first capacitors Cp(2), Cp(4), ..., Cp(2N) and the second capacitors Cq(2), Cq(4), ..., Cq(2N) in the first series circuit section 4 are sequentially added to the first DC voltage VDC1, so that the absolute value of the second DC voltage VDC2 is ultimately about 35kV.

[0031] [Explanation of Effects] The effects obtained by the boost rectifier circuits according to each embodiment having the above configuration will be explained below. Figure 4 is a circuit diagram showing a boost rectifier circuit 10A according to the first comparative example. The boost rectifier circuit 10A includes an AC power supply 16, a transformer 25, and a half-wave rectifier type CW circuit section 7A. In the boost rectifier circuit 10A, the secondary winding 25b and the resistor R1 are connected in series. The half-wave rectifier type CW circuit section 7A is connected between one end of the secondary winding 25b (the terminal not connected to the resistor R1) and one end of the resistor R1 (the terminal not connected to the secondary winding 25b). The half-wave rectifier type CW circuit section 7A is N ２ pieces (N in the diagram) ２ (Example of the case where =6) Capacitor Cd(1) to Cd(N ２ ) and N ２ The number of diodes Dd(1) to Dd(N) ２)(It) has. The odd-stage capacitors Cd(2n - 1) are connected in series with each other, and one end thereof is connected to one end of the secondary winding 25b. The even-stage capacitors Cd(2n) are connected in series with each other, and one end thereof is connected to one end of the resistor R1. One end of the resistor R1 is connected to the reference potential line GND. And the anode of Dd(n) is connected to one electrode of the capacitor Cd(n), and the cathode of Dd(n) is connected to the other electrode of the capacitor Cd(n + 1). However, the cathode of the diode Dd(N ２ The cathode of) is connected to one electrode of the capacitor Cd(N ２ - 1). Each of the resistors Ra(1) and Ra(2) is connected between the node between the even-stage capacitors Cd(2n) and the reference potential line GND. In the example of FIG. 4, the resistor Ra(1) is connected between the node between the capacitor Cd(2) and the capacitor Cd(4) and the reference potential line GND. The resistor Ra(2) is connected between the node between the capacitor Cd(4) and the capacitor Cd(6) and the reference potential line GND. The load RL is connected between one electrode of the capacitor (capacitor Cd(N ２ )) that is the farthest from the secondary winding 25b among the even-stage capacitors Cd(2n) and the reference potential line GND.

[0032] FIG. 5 is a circuit diagram showing a boost rectifier circuit 10B according to a second comparative example. The boost rectifier circuit 10B includes a DC power supply 11, an H-bridge circuit 12, transformers 21 and 26, and a full-wave rectifier type CW circuit section 7B. The secondary winding 21b of the transformer 21 and the secondary winding 26b of the transformer 26 are connected in series with each other. In the boost rectifier circuit 10B, two resistors R3 and R4 are connected in series between the secondary winding 21b and the secondary winding 26b, and the connection point of the resistors R3 and R4 is connected to the reference potential line GND.

[0033] The full-wave rectifier type CW circuit section 7B has N ３ pieces (the case of N ３ = 3 is exemplified in the figure) of capacitors Ce(1) to Ce(N ３ ), N ３ pieces of capacitors Cf(1) to Cf(N ３ ), N ３The number of capacitors Cg(1) to Cg(N) ３ Capacitors Ce(n) are connected in series with each other, and one end of each is connected to the connection point of resistors R3 and R4. Capacitors Cf(n) are connected in series with each other, and one end of each is connected to one end of a series circuit consisting of secondary windings 21b and 26b and resistors R3 and R4. Capacitors Cg(n) are connected in series with each other, and one end of each is connected to the other end of the series circuit. Capacitors 61 and load RL are connected in parallel with each other. Capacitors 61 and load RL are connected in parallel with each other, and each of them is connected to capacitors Ce(1) to Ce(N) ３ ) The capacitor furthest from the secondary winding 21b (capacitor Ce(N) ３ It is connected between one electrode of the )) and the reference potential line GND.

[0034] The full-wave rectifier type CW circuit section 7B is 2N ３ Diodes De(1) to De(2N) ３ ) and 2N ３ The number of diodes Df(1) to Df(2N) ３ ) and further have . The cathode of the odd-numbered diode De(2n-1) is connected to one electrode of capacitor Cf(n), and the anode of diode De(2n-1) is connected to the other electrode of capacitor Ce(n). The cathode of the even-numbered diode De(2n) is connected to one electrode of capacitor Ce(n), and the anode of diode De(2n) is connected to the other electrode of capacitor Cf(n+1). However, the final stage diode De(2N ３ The anode of ) is capacitor Cf(N ３ The cathode of the odd-numbered diode Df(2n-1) is connected to one electrode of capacitor Cg(n), and the anode of diode Df(2n-1) is connected to the other electrode of capacitor Ce(n). The cathode of the even-numbered diode Df(2n) is connected to one electrode of capacitor Ce(n), and the anode of diode Df(2n) is connected to the other electrode of capacitor Cg(n+1). However, the final stage diode Df(2N ３ The anode of ) is capacitor Cg(N ３is connected to one of the electrodes of ( ).

[0035] Hereinafter, taking the boost rectifier circuit 1A according to the second embodiment as an example, the effects when compared with the boost rectifier circuit 10A according to the first comparative example and the boost rectifier circuit 10B according to the second comparative example will be described. FIG. 6(a) is a diagram showing an example of the ripple voltage superimposed on the second DC voltage VDC2 generated by each of the boost rectifier circuit 1A, the boost rectifier circuit 10A, and the boost rectifier circuit 10B. FIG. 6(b) is an example showing a comparison of the ripple voltage, the number of components, the number of transformers, and the rise time of the output voltage for each of the boost rectifier circuit 1A, the boost rectifier circuit 10A, and the boost rectifier circuit 10B, with the numerical values in the boost rectifier circuit 1A converted to 1. In FIG. 6(b), the ratios when the ripple voltage, the number of components, the number of transformers, and the rise time of the output voltage of the boost rectifier circuit 1A are set to 1 are shown. In the example of FIG. 6, the DC power supply 11 generates a voltage of 50 V, and the turns ratio of the transformer 21 is 1 to 100.

[0036] As shown in FIG. 6(a), the ripple voltage in the boost rectifier circuit 1A according to the second embodiment is about 104 Vp-p. On the other hand, as shown in FIG. 6(b), the ripple voltage in the boost rectifier circuit 10A according to the first comparative example is about 8 times the ripple voltage in the boost rectifier circuit 1A, and the ripple voltage in the boost rectifier circuit 10B according to the second comparative example is about 1 / ( ) 5 of the ripple voltage in the boost rectifier circuit 1A. However, since the boost rectifier circuit 10B includes two transformers 21 and 26, an error may occur between the inductances of the windings of the transformers 21 and 26. In this case, the frequency of the ripple voltage may deviate from the frequency for driving the H-bridge circuit 12. In contrast, since the boost rectifier circuit 1A includes one transformer 21, there is no influence due to inductance error.

[0037] As shown in Figure 6(b), the number of components in the boost rectifier circuit 1A according to the second embodiment is reduced to about half the number of components in the boost rectifier circuit 10B according to the second comparative example. Since the boost rectifier circuit 10B includes two transformers, the number of transformers in the boost rectifier circuit 1A is reduced to half the number of transformers in the boost rectifier circuit 10B. Furthermore, the rise time required for the output voltage of the boost rectifier circuit 1A to rise from 0V to the second DC voltage VDC2 when the power is turned on was also examined. The rise time in the boost rectifier circuit 1A is shorter than the rise time in the boost rectifier circuit 10A according to the first comparative example and the rise time in the boost rectifier circuit 10B according to the second comparative example. In other words, the boost rectifier circuit 1A according to the second embodiment has the advantage of having a smaller ripple voltage than the boost rectifier circuit 10A according to the first comparative example and having fewer components than the boost rectifier circuit 10B according to the second comparative example.

[0038] Next, the ripple voltage superimposed on the second DC voltage VDC2 is compared among the boost rectifier circuit 1A according to the second embodiment, the boost rectifier circuit 1 according to the first embodiment, and the boost rectifier circuit 1B according to the third embodiment. As mentioned above, when the ripple voltage in boost rectifier circuit 1A is approximately 104 Vp-p, the ripple voltage in boost rectifier circuit 1 is also approximately 104 Vp-p. That is, boost rectifier circuit 1A and boost rectifier circuit 1 exhibit almost the same ripple voltage characteristics. When the ripple voltage in boost rectifier circuit 1A is approximately 104 Vp-p, the ripple voltage in boost rectifier circuit 1B is approximately 92.5 Vp-p. The ripple voltage in boost rectifier circuit 1B is smaller than the ripple voltage in boost rectifier circuit 1A and boost rectifier circuit 1.

[0039] [Effects] In the boost rectifier circuits 1, 1A, and 1B, by providing the full-wave rectifier circuit section 3 or the full-wave rectifier circuit section 3A immediately after the transformer 21, it is possible to generate the first DC voltage VDC1 while suppressing ripple by utilizing both half-waves of the AC voltage generated by the secondary winding 21b of the transformer 21. Furthermore, the boost rectifier circuits 1, 1A, and 1B employ a half-wave rectifier type CW circuit, which has fewer components than a full-wave rectifier type CW circuit. In the boost rectifier circuits 1, 1A, and 1B, the phase of the output voltage from the first half-wave rectifier type CW circuit section 7 and the phase of the output voltage from the second half-wave rectifier type CW circuit section 8 are in opposite phases, so the noise superimposed on the first series circuit section 4 cancels each other out. In addition, the boost rectifier circuits 1, 1A, and 1B do not require the use of two transformers or a transformer with a center tap, as is the case with the full-wave rectifier type boost rectifier circuit. This allows for the generation of a second DC voltage VDC2 while effectively suppressing ripple. Therefore, by combining a full-wave rectifier circuit and a half-wave rectifier CW circuit, a simple structure can be achieved while suppressing ripple voltage.

[0040] The full-wave rectifier circuit section 3 may include capacitors 31, 32, 33, diodes 34, 35, 36, and 37. The anode of diode 34 may be connected to one electrode of capacitor 31, and the cathode of diode 34 may be connected to one electrode of capacitor 32. The anode of diode 35 may be connected to one electrode of capacitor 32, and the cathode of diode 35 may be connected to one end 21c of the secondary winding 21b. The anode of diode 36 may be connected to one electrode of capacitor 31, and the cathode of diode 36 may be connected to one electrode of capacitor 33. The anode of diode 37 may be connected to one electrode of capacitor 33, and the cathode of diode 37 may be connected to the other end 21d of the secondary winding 21b. The other electrode of capacitor 31 may be connected to the reference potential line GND. The other electrode of capacitor 32 may be connected to the other end 21d of the secondary winding 21b. The other electrode of capacitor 33 may be connected to one end 21c of the secondary winding 21b. In this case, the amount of charge stored in capacitor 31 can be increased by utilizing the positive and negative half-waves of the AC voltage generated in the secondary winding 21b, thereby increasing the voltage boost ratio in the full-wave rectifier circuit 3.

[0041] In the full-wave rectifier circuit section 3A, the anode of diode 42 may be connected to one electrode of capacitor 41, and the cathode of diode 42 may be connected to one end 21c of the secondary winding 21b. The anode of diode 43 may be connected to one end 21c of the secondary winding 21b, and the cathode of diode 43 may be connected to the other electrode of capacitor 41. The anode of diode 44 may be connected to one electrode of capacitor 41, and the cathode of diode 44 may be connected to the other end 21d of the secondary winding 21b. The anode of diode 45 may be connected to the other end 21d of the secondary winding 21b, and the cathode of diode 45 may be connected to the other electrode of capacitor 41. The other electrode of capacitor 41 may be connected to the reference potential line GND. In this case, the full-wave rectifier circuit section also has a simple configuration with fewer components, making it easier to further reduce the number of components in the boost rectifier circuit. [Modified Example]

[0042] The boost rectifier circuits 1, 1A, and 1B in this disclosure are not limited to the embodiments described above, and various other modifications are possible. For example, in each of the above embodiments, this disclosure may be applied to a boost rectifier circuit for outputting a negative high voltage, or it may be applied to a boost rectifier circuit for outputting a positive high voltage. In that case, the orientation of the diodes in each embodiment will be reversed. Although the boost rectifier circuits 1, 1A, and 1B in each of the above embodiments include a CW circuit, they can be configured with various other boost rectifier circuits, not limited to a CW circuit.

[0043] Figure 7 is a circuit diagram showing the configuration of a boost rectifier circuit according to the first modified example. The boost rectifier circuit 1C according to the first modified example differs from the boost rectifier circuit 1 according to the first embodiment in that it has a capacitor 61, diode 62, diode 63, capacitor 64, diode 65, diode 66, and a full-wave rectifier circuit section 3B instead of diodes 22, diode 23, and full-wave rectifier circuit section 3. The other electrode of capacitor 61 is connected to the other end 21d of the secondary winding 21b. One electrode of capacitor 61 is connected to the cathode of diode 62 and the anode of diode 63. The anode of diode 62 is connected to the other electrode of the second capacitor Cq(2), which is the input terminal of the first series circuit section 4. The cathode of diode 63 is connected to one end 21c of the secondary winding 21b. The other electrode of capacitor 64 is connected to one end 21c of the secondary winding 21b. One electrode of capacitor 64 is connected to the cathode of diode 65 and the anode of diode 66. The anode of diode 65 is connected to the other electrode of the second capacitor Cq(2). The cathode of diode 66 is connected to the other end 21d of the secondary winding 21b.

[0044] The full-wave rectifier circuit section 3B is connected to both ends of the secondary winding 21b. The full-wave rectifier circuit section 3B includes a capacitor 51, a capacitor 52, a diode 53, a diode 54, a diode 55, and a diode 56. The cathode of diode 53 is connected to the other electrode of capacitor 51, and the anode of diode 53 is connected to one end 21c of the secondary winding 21b. The cathode of diode 54 is connected to one end 21c of the secondary winding 21b, and the anode of diode 54 is connected to one electrode of capacitor 51. The other electrode of capacitor 52 is connected to one electrode of capacitor 51, and one electrode of capacitor 52 is connected to the other electrode of the second capacitor Cq(2). The other electrode of capacitor 51 is connected to the reference potential line GND. The cathode of diode 55 is connected to the other electrode of capacitor 51, and the anode of diode 55 is connected to the other end 21d of the secondary winding 21b. The cathode of diode 56 is connected to the other end 21d of the secondary winding 21b, and the anode of diode 56 is connected to one electrode of capacitor 51.

[0045] The full-wave rectifier circuit 3B generates a first DC voltage VDC1 by rectifying the AC voltage generated in the secondary winding 21b. Unlike the full-wave rectifier circuit 3 of the first embodiment, the full-wave rectifier circuit 3B does not need to boost the AC voltage. In the full-wave rectifier circuit 3B, the positive and negative half-waves of the AC voltage in the secondary winding 21b are rectified by diodes 53 to 56, and the first DC voltage VDC1 is output from one electrode of capacitor 52. That is, because capacitors 51 and 52 are connected in series, the magnitude of the voltage generated in each capacitor is reduced. For example, if the absolute value of the first DC voltage VDC1 is 10kV, the sum of the voltages generated in capacitor 51 and capacitor 52 will be 10kV. In this case, the ratio of the voltages generated in capacitor 51 and capacitor 52 may change depending on the magnitude of the load RL. For example, the ratio of the voltage generated at capacitor 51 to the voltage generated at capacitor 52 may be 6:4 or 5:5.

[0046] Figure 8 is a circuit diagram showing the configuration of a boost rectifier circuit according to the second modification. The boost rectifier circuit 1D differs from the boost rectifier circuit 1C of the first modification in that it is made up of N+1 (where N is an integer of 2 or more; the figure illustrates the case where N=3) third capacitors Cp(1), Cp(3), ..., Cp(2N+1) connected in series, and that 2N+1 diodes Dp(1), Dp(2), ..., Dp(2N+1) connect the first series circuit section 4 and the second series circuit section 5. In the example in Figure 8, the anode of diode Dp(1) is connected to the other electrode of capacitor Cq(2), and the cathode of diode Dp(1) is connected to one electrode of capacitor Cp(1). The anode of diode Dp(2n) (where n = 1, 2, 3, ...) is connected to one electrode of capacitor Cp(2n+1), and the cathode of diode Dp(2n) is connected to the other electrode of capacitor Cp(2n). The anode of diode Dp(2n+1) is connected to one electrode of capacitor Cp(2n), and the cathode of diode Dp(2n+1) is connected to one electrode of capacitor Cp(2n+1).

[0047] In the boost rectifier circuit 1D, the voltage of the first stage of the second series circuit section 5 is divided at the third capacitor Cp(1) and the third capacitor Cp(3) of the second series circuit section 5. As a result, the absolute value of the voltage generated at the third capacitor Cp(1) of the second series circuit section 5 in this modified example is smaller than the absolute value of the voltage generated at the third capacitor Cp(1) of the second series circuit section 5 in the first modified example.

[0048] While the principles of the present invention have been illustrated and described in preferred embodiments, it will be recognized by those skilled in the art that the present invention can be modified in arrangement and detail without departing from such principles. The present invention is not limited to the specific configurations disclosed in these embodiments. Accordingly, all modifications and changes arising from the scope of the claims and their spirit are claimed.

[0049] 1, 1A, 1B... Boost rectifier circuit, 3, 3A... Full-wave rectifier circuit section, 4... First series circuit section, 5... Second series circuit section, 6... Third series circuit section, 7... First half-wave rectifier type CW circuit section (first half-wave rectifier type boost circuit section), 8... Second half-wave rectifier type CW circuit section (second half-wave rectifier type boost circuit section), 21... Transformer, 21a... Primary winding, 21b... Secondary winding, 21c... One end of the secondary winding, 21d... Other end of the secondary winding, 31, 41... Capacitor (first rectifier capacitor), 32... Capacitor (second rectifier capacitor), 33... Capacitor (third rectifier capacitor), 34, 42...diodes (first diodes), 35, 43...diodes (second diodes), 36, 44...diodes (third diodes), 37, 45...diodes (fourth diodes), Cp(2), Cp(4), Cp(2N)...first capacitors, Cq(2), Cq(4), Cq(2N)...second capacitors, Cp(1), Cp(3), Cp(2N-1)...third capacitors, Cq(1), Cq(3), Cq(2N-1)...fourth capacitors, GND...reference potential line, VDC1...first DC voltage, VDC2...second DC voltage.

Claims

1. A transformer comprising a primary winding and a secondary winding, wherein an AC voltage is input to the primary winding; a full-wave rectifier circuit section connected to the secondary winding and generating a first DC voltage by rectifying the AC voltage generated in the secondary winding; a first series circuit section comprising a plurality of first capacitors and a plurality of second capacitors connected alternately in series; a second series circuit section comprising a plurality of third capacitors connected in series; and a third series circuit section comprising a plurality of fourth capacitors connected in series, wherein one end of the second series circuit section is connected to one end of the secondary winding, one end of the third series circuit section is connected to the other end of the secondary winding, one end of the first series circuit section is connected to the output terminal of the full-wave rectifier circuit section, and the third capacitor of the second series circuit section and the first capacitor of the first series circuit section constitute a first half-wave rectifier boost circuit section. The fourth capacitor of the third series circuit section and the second capacitor of the first series circuit section constitute a second half-wave rectifier boost circuit section, the first half-wave rectifier boost circuit section rectifies and boosts the AC voltage generated in the secondary winding, the second half-wave rectifier boost circuit section rectifies and boosts the AC voltage generated in the secondary winding in the opposite phase to that of the first half-wave rectifier boost circuit section, and the output voltage from the first half-wave rectifier boost circuit section and the output voltage from the second half-wave rectifier boost circuit section are added to the first DC voltage in the first series circuit section to generate a second DC voltage, thus creating a boost rectifier circuit.

2. The full-wave rectifier circuit includes a first rectifier capacitor, a second rectifier capacitor, a third rectifier capacitor, a first diode, a second diode, a third diode, and a fourth diode, wherein the anode of the first diode is connected to one electrode of the first rectifier capacitor, the cathode of the first diode is connected to one electrode of the second rectifier capacitor, the anode of the second diode is connected to one electrode of the second rectifier capacitor, the cathode of the second diode is connected to one end of the secondary winding, the anode of the third diode is connected to one electrode of the first rectifier capacitor, the cathode of the third diode is connected to one electrode of the third rectifier capacitor, the anode of the fourth diode is connected to one electrode of the third rectifier capacitor, and the cathode of the fourth diode is connected to the other end of the secondary winding. The boost rectifier circuit according to claim 1, wherein the other electrode of the first rectifier capacitor is connected to a reference potential line, the other electrode of the second rectifier capacitor is connected to the other end of the secondary winding, and the other electrode of the third rectifier capacitor is connected to one end of the secondary winding.

3. The boost rectifier circuit according to claim 1, wherein the full-wave rectifier circuit section includes a first rectifier capacitor, a first diode, a second diode, a third diode, and a fourth diode, the anode of the first diode being connected to one electrode of the first rectifier capacitor, the cathode of the first diode being connected to one end of the secondary winding, the anode of the second diode being connected to one end of the secondary winding, the cathode of the second diode being connected to the other electrode of the first rectifier capacitor, the anode of the third diode being connected to one electrode of the first rectifier capacitor, the cathode of the third diode being connected to the other end of the secondary winding, the anode of the fourth diode being connected to the other end of the secondary winding, the cathode of the fourth diode being connected to the other electrode of the first rectifier capacitor, and the other electrode of the first rectifier capacitor being connected to a reference potential line.

4. The boost rectifier circuit according to claim 1 or 2, wherein the first half-wave rectifier boost circuit further comprises a plurality of diodes, the cathode of the diode closest to the secondary winding is connected to a node between the third capacitor closest to the secondary winding and the next closest third capacitor, and the anode of the diode closest to the secondary winding is connected to the output terminal of the full-wave rectifier circuit.

5. The boost rectifier circuit according to claim 1, wherein the full-wave rectifier circuit section includes a plurality of capacitors connected in series with each other, and the plurality of capacitors are connected between a reference potential line and one end of the first series circuit section.

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