JPH0746070Y2 - Double voltage rectifier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention is to obtain a DC power by rectifying and smoothing an AC power supply, which has a relatively high DC voltage which is almost twice the AC power supply voltage. The present invention relates to a voltage doubler rectifier that can be obtained without using a transformer.

<Prior art> Generally, among rectifiers that rectify a commercial AC power source to a DC power source such as a vacuum tube or a transistor circuit, a doubling of a conventional rectifier device for obtaining a relatively higher voltage than an AC voltage without using a transformer. The voltage rectifier has a structure as shown in FIG. That is, a series circuit of a first diode D1 and a first capacitor C1 and a series circuit of a second diode D2 and a second capacitor C2 are connected between both AC input terminals I1 and I2 connected to the commercial AC power supply 1. And D1 and D2 are connected in parallel so that both diodes D1 and D2 are in anti-parallel, and the first diode D1
And the connection point between the first capacitor C1 and the positive side output terminal +0, and the second capacitor C2 and the second diode D2
A bridge circuit is configured by deriving a connection point between the and the negative output terminal -0. Then, when the potential on one of the AC input terminals I1 side is high, the first diode D1 conducts and charges the first capacitor C1, the phase of the AC power supply voltage is reversed, and the other AC input terminal I2 side When the electric potential of the capacitor becomes high, the second diode D2 becomes conductive and the second capacitor C2 is charged, and the charge of both capacitors C1 and C2 is superposed, and the AC power supply voltage is applied between both output terminals +0 and −0. It is designed to obtain a DC output voltage 2E that is almost twice that of E.

<Problems to be Solved by the Invention> By the way, in a normal full-wave rectifier, for example, a bridge full-wave rectifier, a rectifying part using a diode and a smoothing part using a capacitor are independent of each other, and the smoothing part is choked. The configuration can be appropriately changed according to the application such as the input method and the capacitor input method. However, in the voltage doubler rectifier, since the diodes D1 and D2 having a rectifying function and the capacitors C1 and C2 having a smoothing function are integrally configured to obtain a voltage doubler, these are separated and individually It is impossible or very difficult to choose. Therefore, in comparison with the AC voltage E of the commercial AC power supply 1 shown in FIG.
And the charging current flowing into the second capacitors C1 and C2 is
As shown in (c) and (d) of the figure, the waveform has a sharp peak, and the input currents of both AC input terminals I1 and I2 also have a waveform having a sharp peak as shown in (b) of the figure. Therefore, the power factor of the AC power supply becomes low, and the waveform of the AC power supply system is disturbed by the mixing of noise, which causes a harmonic interference.

Therefore, in order to solve the above-mentioned problem, a means for suppressing the peak of the current waveform generated by inserting a resistor or a reactor in series with the AC power supply 1 in the vicinity of the peak value of the power supply voltage for each half cycle of the AC is provided. Although it may be possible to take measures, in order to sufficiently suppress the peak of the current to reduce the waveform distortion and to set the power factor to a high power factor (usually 85% or more), the resistance value of the resistor and the impedance of the reactor. In the case of a large value and a large capacity load, the ohmic cross becomes large and the volume and weight become large, which is not suitable for practical use.

<Purpose of the Invention> The present invention has been made in view of such conventional technical problems, and an object thereof is to provide a voltage doubler rectifier capable of obtaining a high power factor with a simple configuration.

<Means for Solving the Problems> In order to achieve the above-mentioned object, the voltage doubler rectifier of the present invention is configured such that the anode of the first diode and the cathode of the second diode are connected in series and the first capacitor is connected. And a second capacitor are connected in series, the cathode of the first diode and the first capacitor thereof, and the anode of the second diode and the second capacitor thereof are directly connected, and the first and second capacitors are connected. An AC power supply is connected to the connection point of the second diode and the connection point of the first and second capacitors, and the connection point of the first diode and the first capacitor is led to the positive output terminal. At the same time, the connection point between the second diode and the second capacitor is led to the negative output terminal to form a bridge circuit, and the negative output terminal and the positive output terminal are negative. In a voltage doubler rectifier connected to both input terminals of a load, a first reactor is connected in series between the first diode and a first capacitor, and a third reactor is provided at both ends of the first reactor. Each of the anodes of the diode and the fourth diode are connected in parallel, and the connection point of each cathode of the third and fourth diodes is led to the positive side output terminal, and is connected to the fourth diode. A fourth capacitor is connected in parallel, a second reactor is connected in series between the second diode and the second capacitor, and a fifth diode and a sixth diode are provided at both ends of the second reactor. Connect the cathodes of the diodes in parallel,
And connecting a connection point of the anodes of the fifth and sixth diodes to the negative output terminal, and connecting a fifth capacitor in parallel to the sixth diode;
Between the positive side output terminal located after the connection point of each cathode of the fourth diode and the negative side output terminal located after the connection point of each anode of the fifth and sixth diodes, the third output terminal Characterized by connecting a capacitor.

<Operation> By the first and second reactors, a current is blocked from flowing into the first capacitor and the second capacitor from the AC power source, and a part of the current is partially absorbed by the third diode and the fifth capacitor. The peak value is suppressed to a low level and the waveform is improved by flowing through the diode (1), so that the high frequency component can be reduced and the power factor becomes high. Also, due to the resonance caused by the first and second capacitors and the corresponding first and second reactors, the output voltage is at the same phase as the AC power supply voltage and at a point slightly delayed from this point. The waveforms each have a peak value, and the amount of output energy increases even when the total capacitance of the smoothing first and second capacitors is reduced. Further, the size of the first reactor can be reduced by the fourth capacitor, and a high power factor can be maintained.
Further, also with the fifth capacitor, the size of the second reactor can be similarly reduced and a high power factor can be maintained. Then, the ripple voltage can be reduced by setting the third capacitor to an appropriate value.

<Embodiment> Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 1 showing one embodiment of the present invention, the same or equivalent parts as in FIG. 7 are designated by the same reference numerals.
As the smoothing first and second capacitors c1 and c2, capacitors having smaller capacities than the capacitors C1 and C2 shown in FIG. 7 are used. In addition, the first reactor L1 is inserted and connected between the first diode D1 and the first capacitor c1, and the third and fourth diodes D3 and D4 are connected to the first reactor L1. The respective anodes are connected to both ends of the reactor L1 and are connected in anti-series, and the connection point of the cathodes of both diodes D3 and D4 is led to the positive output terminal +0. Meanwhile, the second diode D2 and the second diode D2
The second reactor L2 is inserted and connected between the capacitor c2 and the capacitor c2, and the fourth and fifth diodes D5 and D6 are connected to the second reactor L2 and the cathodes are respectively connected to both ends of the reactor L2. They are connected to each other and connected in anti-series, and the connection point of the anodes of both diodes D5 and D6 is led to the negative output terminal -0.

Next, the operation of the voltage doubler rectifier of the above embodiment will be described with reference to FIG. 2 in which it is applied to a discharge tube lighting device.
In FIG. 2, both output terminals + 0, -0 of the apparatus of FIG. 1 are connected to a DC-AC inverter 2, and a high frequency current is supplied from this inverter 2 to a discharge tube serving as a load 3.

Now, as the discharge tube of the load 3, a tube power of 140 W, a tube current of 1.1 A and a tube voltage of 130 V is used, and the constants of the circuit components of the DC-AC inverter 2 are appropriately selected, and the smoothing first and first The capacitors c1 and c2 of No. 2 are 47 μF, and the first and second reactors L1 and L2 are E1 type electromagnetic steel sheets with a width of 41 mm and the stacking thickness of 17 mm.
A coil having a diameter of 0.5 mm wound 355 times and provided with an appropriate core gap is used. Then, without connecting the third capacitor C3 shown in FIG. 2, the capacitor shown in FIG.
As a result of exciting the discharge tube by applying an AC voltage of 0 V (effective value), the input current is 1.87 A as shown in Fig. 3 (b).
(7.2A between positive and negative peaks), input power is 164W and power factor is 8
It was 9.1%. Next, 22μ as the third capacitor C3
Good results were obtained with an input current of 1.77 A, an input power of 162 W, and a power factor of 91.5% when the F capacity was used and the other conditions were the same as above. At this time, the current flowing through both reactors L1 and L2 is
It was 0.5A. Incidentally, for comparison, the result of replacing the conventional voltage doubler rectifier shown in FIG. 7 with the device shown in FIG. 1 in FIG. 2 is shown as the DC-AC inverter 2 and the load 3 described above. If the same one is used and almost the same excitation as that described above is applied to the discharge tube, the first and second capacitors C1 and C2 are both 220
A μF type is required, and the input current at that time is shown in Fig. 8 (b).
The waveform becomes as shown in, and becomes about 3.0A (effective value),
The positive and negative peak current became 18.0A, the input power was 166.5W and the power factor was 55.5%. That is, in the device of the embodiment, the total capacitance of the capacitors c1 and c2 is small, and the power factor is remarkably high.

The waveforms of the input currents of the first capacitor c1 and the second capacitor c2 in the case of FIG. 2 are as shown in FIGS. 3 (c) and 3 (d), respectively. That is, the measured results show that the input currents of the capacitors c1 and c2 are both 1.1 A.
(Rms value), the current between zero and peak was 3.2A. For comparison, the capacitors shown in FIGS. 8 (c) and 8 (d)
The input currents of C1 and C2 are both 1.9A (effective value),
The current between zero and peak was 8.0A. Therefore, in both input current and capacitor current, reactor L
The current is prevented from directly flowing into the capacitors c1 and c2 by 1, L2, and a part of the current flows through the third diode D3 and the fifth diode D5, so that the peak value is suppressed to be low. It is shown that the waveform is improved, the high frequency component can be reduced, and the power factor is remarkably increased.

Further, in FIG. 4, the output voltage when the third capacitor C3 is not connected to the power supply voltage of FIG. 4A has a waveform as shown in FIG.
The output voltage when a C3 of 22 μF is used has a waveform as shown in FIG. Incidentally, FIG. 7D is the waveform of the output voltage of FIG. 7 shown for comparison. As is clear from the comparison between (a) and (b), (c),
Due to the resonance caused by the first capacitor c1 and the first reactor L1 and the second capacitor c2 and the second reactor L2,
In the AC half cycle, the waveforms have peaks at the point of the same phase as the AC power supply voltage waveform and at the point of the phase slightly delayed from this point.
Although the total capacitance of the capacitor is smaller than that of the conventional device as described above, the waveform area is large and the output energy amount is large. In addition, since it has two peaks in the AC half cycle, in the discharge tube lighting device in which the DC-AC inverter 2 shown in FIG. Does not appear at the load end as it is, the luminous efficiency of the legal tube is improved. Furthermore, in a discharge tube for ultraviolet radiation, the efficiency of which greatly changes depending on the magnitude of the instantaneous value of the excitation power, the effect of significantly improving the ultraviolet radiation efficiency can be obtained.

FIG. 5 shows another embodiment of the present invention, which is shown in FIGS.
The same or equivalent parts as those in the drawing are designated by the same reference numerals, and the difference from the above-mentioned embodiment is that the fourth diode C4 has a fourth capacitor C4 and the sixth diode D6 has a fifth capacitor. Only C5 is connected in parallel.

This device is replaced with the first device in FIG. 2 so that the discharge tube is excited under the same conditions as in the above embodiment,
Moreover, when the constants of the respective circuit components are appropriately selected so that the reactors L1 and L2 that are as small as possible can be used, the first and second capacitors c1 and c2 are 47 μ.
F, the third capacitor C3 is 22μF, and the fourth and fifth capacitors C4, C5 are 3.3μF, and a magnetic steel sheet with a width of 35mm and a stack thickness of 10mm is added to the winding of 0.5mm in diameter. As a result of combining reactors L1 and L2 that have been wound 300 times and provided an appropriate gap, input current 1.82A (effective value),
We were able to obtain an input power of 164 W and a power factor of 90.1%.

FIG. 6 shows still another embodiment of the present invention, in which the same or equivalent parts as those in FIGS. 1, 2 and 5 are designated by the same reference numerals. The difference is that the bridge full-wave rectifier circuit 4 including four diodes D7, D8, D9, D10 instead of the first and second diodes D1, D2 is connected via a switch S. In this example, 200V load 5
When the AC power supply 1 is 100V, the switch S is turned on to perform double voltage rectification, and the AC power supply 1 is 200V.
At this time, the switch S is turned off to perform full-wave bridge rectification. During the voltage doubler rectification with the switch S in the ON state, the eighth diode D8 functions as the first diode D1 of each of the above-described embodiments, and the seventh diode D7 functions as the second diode D2. Further, in this embodiment, in both cases of the double voltage rectification by switching the switch S and the full-wave bridge rectification, a high power factor and low harmonics are obtained.

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various embodiments can be considered without departing from the scope of the claims. For example, the DC-AC shown in FIG.
It is not applicable only to the discharge tube lighting device in which the inverter 2 and the load 3 including the discharge tube are combined.
As shown in FIG. 6, the DC power obtained by rectifying the AC power supply 1 may be directly connected to the device 5 used as a power supply.
The power may be supplied to the load after voltage transformation or constant voltage conversion via a switching regulator or the like. Further, in the above-described embodiment, the case where the third capacitor C3 is not connected and the case where the third capacitor C3 having a capacitance of 22 μF is connected have been described. When is made small, the ripple voltage can be reduced by selecting an appropriate capacitance of several hundreds to several thousands μF as the third capacitor C3.

<Effect of Device> As described in detail above, according to the voltage doubler rectifier of the present invention,
The first and second reactors for rectification and the corresponding first and second capacitors for smoothing are respectively connected to the first and second reactors, respectively. The connection points of the cathodes of the third and fourth diodes and the fifth connection, respectively, which are connected in anti-series.
And connecting the anodes of the sixth diode to the output terminals on the positive side and the negative side, respectively, and connecting the fourth capacitor and the fifth capacitor in parallel to the fourth diode and the sixth diode, respectively. In addition, the positive side output terminal located after the connection point of each cathode of the third and fourth diodes and the negative side output terminal located after the connection point of each anode of the fifth and sixth diodes Since a third capacitor is connected between them, it is possible to prevent the current from directly flowing into the corresponding capacitor by each reactor, and it is possible to control the peak value of the capacitor current to a low value, and the harmonics due to this peak current. Can be controlled, and the power factor can be increased from 87% to around 90%. Further, as the smoothing capacitor, one having a small capacity can be used, and further, due to the high power factor, the diode capacity may be small, and the size can be reduced. Furthermore, since the inrush current of the capacitor is reduced, heat generation can be controlled, and the life of the capacitor can be extended. Further, the size of the first and second reactors can be further reduced by the fourth and fifth capacitors, and it is possible to further promote miniaturization while maintaining a high power factor.

Since the output voltage at load has a waveform with a small valley compared to the size of the capacitor capacity, the luminous efficiency is particularly high when it is applied to a discharge tube lighting device such as a low pressure sodium lamp or an ultraviolet ray generating lamp. There is an advantage that the radiation efficiency is significantly improved. In addition, by setting the third capacitor to an appropriate value, the ripple voltage can be reduced, and the third capacitor can be used as a power source in equipment that is desired to be used under a low ripple voltage, such as audio equipment. ,
It is also effective as a power source for switching regulators, etc., and has versatility.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of an embodiment of the present invention, FIG. 2 is a block diagram of a discharge tube lighting device to which FIG. 1 is applied, and FIGS. 3 (a) to 3 (d) are respectively FIG. 4A to 4D are timing charts showing the voltage and radio wave waveform of each part of FIG. 4, and FIG. 4A to FIG. 4D show the input voltage of FIG. 2 and the output voltage with and without the third capacitor and for comparison. The respective output voltage waveform diagrams of the conventional device shown in FIGS. 5 and 6 are electrical circuit diagrams of another embodiment of the present invention, FIG. 7 is an electrical circuit diagram of the conventional device, and FIG. 7 is a timing chart showing voltage and current waveforms at various parts of FIG. 7. I1, I2 ...... AC input terminal ＋0 …… Positive side output terminal −0 …… Negative side output terminal D1, D8 …… First diode D2, D7 …… Second diode 3 to D6 …… Third to third 6 diode c1 ... first capacitor c2 ... second capacitor L1 ... first reactor L2 ... second reactor C3 ... third capacitor C4, C5 ... fourth and fifth capacitors

Claims (1)

[Scope of utility model registration request] 1. An anode of a first diode and a cathode of a second diode are connected in series, a first capacitor and a second capacitor are connected in series, and a cathode of the first diode and its first And the anode of the second diode and the second capacitor thereof are directly connected to each other, and the connection point of the first and second diodes, and the connection point of the first and second capacitors described in detail. An AC power source is connected to the first diode and the connection point between the first diode and the first capacitor is led to the positive output terminal, and a connection point between the second diode and the second capacitor is connected to the negative output terminal. In the voltage doubler rectifier in which the negative side output terminal and the positive side output terminal are connected to both input ends of the load. And a first capacitor, a first reactor is connected in series, and anodes of a third diode and a fourth diode are respectively connected in parallel to both ends of the first reactor, and the third reactor is connected. And the fourth
Connecting the cathode of each diode to the positive side output terminal, and connecting a fourth capacitor in parallel to the fourth diode, and between the second diode and the second capacitor. The second reactor is connected in series, and the cathodes of the fifth diode and the sixth diode are respectively connected in parallel to both ends of the second reactor, and the anodes of the fifth and sixth diodes are connected. A connection point is led to the negative output terminal, and a fifth capacitor is connected in parallel to the sixth diode thereof; a positive side located after the connection point of the cathodes of the third and fourth diodes. A voltage doubler rectifier characterized in that a third capacitor is connected between an output terminal and a negative output terminal located at a stage subsequent to a connection point of the anodes of the fifth and sixth diodes.