JPH10108461A - Dc power supply apparatus connecting a plurality of dc converters in parallel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a DC power supply apparatus, which can realize synchronous operation of a plurality of PWM control type DC converters, connected in parallel and can also continue supply of power with the remaining DC converters, even if a DC converter fails. SOLUTION: A plurality of DC converters 1, 2 are connected in parallel. Each DC converter 1, 2 is respectively provided with a triangular wave generating circuits 27, 28 to form a PWM pulse. A series circuit of a first and a second resistors 33, 34 is connected between oscillation capacitors 31, 32 to be connected to the triangular wave generating circuits 27, 28. A first and a second amplifiers 35, 36 are connected in parallel to the first and the second resistors 33, 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC power supply in which DC converters such as switching regulators are connected in parallel.

Generally, a separately-excited switching regulator used in a DC power supply of this type includes an error amplifier for comparing an output voltage with a reference voltage, a triangular wave generation circuit,
It includes a comparator that forms a PWM pulse by comparing a triangular wave with an error signal, and a switching element that turns on and off in response to the PWM pulse. Generally, control parts such as an error amplifier, a triangular wave generation circuit, and a comparator are integrated circuits (I
C), wherein the oscillation capacitor and the timing resistor for obtaining the ramp voltage of the triangular wave generating circuit are externally connected. When operating switching regulators in parallel, attach a timing resistor and oscillation capacitor to the switching regulator (master).
Operate the oscillation circuit to generate a triangular wave. In another switching regulator (slave), the operation of the oscillation circuit is stopped, and the oscillation capacitor terminal is connected to the oscillation capacitor on the master side. Thereby, the switching regulator on the slave side operates with the triangular wave output on the master side, so that synchronous operation becomes possible.

[0003]

However, in this DC power supply, if the capacitor connection terminal on the slave side goes to the ground level for some reason, the terminal of the oscillation capacitor of the master also goes to the ground, and the triangular wave is applied to both the master and the slave. It becomes impossible to obtain. Further, if an abnormality occurs in the triangular wave generation circuit on the master side, a triangular wave cannot be obtained on the slave side. Therefore, power supply becomes impossible due to the failure of one of the master and the slave. Also,
Since the master and the slave were not the same configuration, they had to be manufactured and used separately.

[0004] Therefore, an object of the present invention is to provide a power supply that can be continued even if one of a plurality of DC converters connected in parallel fails, and to synchronize the plurality of DC converters. To provide a DC power supply device that can accurately and easily obtain the DC power supply.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and to achieve the above-mentioned object, the present invention comprises at least first and second DC converters connected in parallel, wherein the first and second DC converters are provided. Each of the DC converters includes a switching element for controlling a voltage level, a triangular wave generating circuit, and a control pulse for forming a control pulse for turning on and off the switching element based on an output of the triangular wave generating circuit. A triangular wave generating circuit having a capacitor for obtaining a triangular wave, a charging circuit and a discharging circuit for the capacitor, and a triangular wave output side of the capacitor of the first and second DC converters. A series circuit of first and second resistors is connected between the terminals, and a first amplifier having a first direction is connected in parallel with the first resistor,
The present invention relates to a DC power supply device, wherein a second amplifier is connected in parallel with the second resistor and having a second direction opposite to the first direction. In addition, as shown in claim 2, first and second diodes can be connected instead of the first and second resistors of claim 1.
Further, a series circuit of first and second diodes opposite to each other is connected between the capacitors of the first and second DC converters, and the first and second DC converters are connected to each other.
The first and second transistors are connected to the diode so that the base and the emitter become anti-parallel, and the first and second transistors are connected.
Can be connected to the power supply. Further, as shown in claim 4, the first and second diodes of claim 3 can be replaced with first and second resistors. Further, as shown in claims 5 and 6, the collectors of the first and second transistors of claims 3 and 4 can be modified so as to be connected to the ground terminal of the capacitor. Also, as described in claim 7, the first and the second
NPN type and PN
Connecting the P-type first and second transistors, connecting the bases of the first and second transistors to each other and also connecting the emitters, connecting the collector of the first transistor to a power supply, Can be connected to the ground terminal of the capacitor. Further, as described in claim 8, third and fourth transistors connected in the same manner as the first and second transistors of claim 7 can be provided.

[0006]

According to the first to fourth aspects of the present invention,
When the voltage of the capacitor of the first DC converter is higher than the voltage of the capacitor of the second DC converter, the first amplifier or the first transistor causes the capacitor of the second DC converter to be charged. , An operation in which the voltages of both capacitors become equal occurs. When the voltage relationship of the capacitor is opposite to the above, the opposite operation occurs. Therefore, the voltage of both capacitors, that is, the triangular wave voltage can be made the same by a simple circuit, so that the first and second DC converters can be favorably synchronized. According to the fifth and sixth aspects of the invention, when the voltage of one capacitor is higher than the voltage of the other capacitor, discharge of one capacitor occurs via the transistor, and the voltages of both capacitors become equal. Therefore, the voltages of both capacitors, that is, the triangular waves, can be accurately matched with a simple circuit, and good synchronous operation of the first and second DC converters becomes possible. Claim 7
According to the invention, when the voltage of the capacitor of the first DC converter is higher than the voltage of the capacitor of the second DC converter, the capacitor of the second DC converter is charged, and both capacitors are charged. The voltage will be the same. Also, the second
When the capacitor of the DC converter is higher than the voltage of the capacitor of the first DC converter, this discharge occurs, and the voltages of both capacitors become equal. Therefore, the voltage of both capacitors, that is, the triangular wave can be accurately matched with a simple circuit, and the synchronous operation can be performed well. According to the invention of claim 8, when the voltage of the capacitor of the first DC converter is higher than the capacitor of the second DC converter, the capacitor of the second DC converter is charged and both capacitors are charged. Become the same. Conversely, when the voltage of the capacitor of the second DC converter is higher than the voltage of the capacitor of the first DC converter, the capacitor of the first DC converter is charged and the voltages of both capacitors become the same. Thereby, the synchronous operation of the first and second DC converters becomes possible. According to the invention of each claim, the first
Also, since the second DC converter has a triangular wave generating capacitor, even if one cannot generate a triangular wave, the other can generate a triangular wave and maintain the operation of the other DC converter. . Further, since the first and second DC converters can be configured in the same manner, mass productivity is improved. Further, since it is not necessary to distinguish between the master and the slave, the usability is improved.

[0007]

First Embodiment Next, a DC power supply according to a first embodiment of the present invention will be described with reference to FIGS. The DC power supply shown in FIG. 1 includes first and second DC converters 1,
2 are connected in parallel. First and second power supplies connected to a common DC power supply 3 and a common load 4
DC converters 1 and 2 include transistors 5 and 6 as conversion switching elements, transformers 7 and 8, rectifying diodes 9 and 10, and smoothing diodes 11 and 12.
, Smoothing reactors 13, 14, smoothing capacitors 15, 16, and output voltage detecting resistors 17, 18, 19,
20; reference voltage sources 21 and 22;
4, a comparator 25 as a control pulse forming circuit,
26, triangular wave generation circuits 27 and 28, timing resistors 29 and 30, oscillation capacitors 31 and 32, first and second resistors 33 and 34 for synchronization, and first and second resistors for synchronization. , And amplifiers 35 and 36.

Since the first and second DC converters 1 and 2 have substantially the same configuration, only the first DC converter 1 will be described in more detail here. The transistor 5 is connected to the DC power supply 3 via the primary winding 7a of the transformer 7. Since the comparator 25 is connected to the base (control terminal) of the transistor 5, the comparator 2
The transistor 5 turns on and off in response to the PWM pulse output from the switch 5. Diodes 9 and 10, reactor 13 and capacitor 1 are connected to secondary winding 7 b of transformer 7.
5 is connected, and the output line 3
3 is connected to the load 4. Voltage detection resistors 17, 18
Is connected between the output line 33 and the ground, and this voltage dividing point is connected to the error amplifier 23. Error amplifier 2
3 sends to the comparator 25 a signal corresponding to the difference between the reference voltage of the reference voltage source 21 and the detection voltage. Comparator 25
Compares the triangular wave voltage obtained from the triangular wave generation circuit 27 with the error signal to form a PWM wave and sends it to the transistor 5.

The triangular wave generating circuit 27 generates a triangular wave with a timing resistor 29 connected between the terminal T1 and the ground and an oscillation capacitor 31 connected between the terminal T2 and the ground. Similarly, in the triangular wave generation circuit 28 of the second DC converter 2, the timing resistor 30 is connected between the terminal T3 and the ground, and the oscillation capacitor 32 is connected between the terminal T4 and the ground. . In order to synchronously generate a triangular wave voltage from the first and second triangular wave generating circuits 27 and 28, capacitors 31 and 3 are used.
A series circuit of first and second resistors 33 and 34 is connected between the two triangular wave output terminals, that is, between terminals T2 and T4. The first and second amplifiers 35 and 36 are connected in parallel to the first and second resistors 33 and 34 with directions opposite to each other. Note that the first and second amplifiers 35,
36 is also connected to the power supply terminal + Vcc.

As shown in FIG. 2, the triangular wave generating circuit 27 includes five transistors Q1, Q2, Q3, Q4, Q5.
, Five resistors R1, R2, R3, R4, R5, two comparators Z1, Z2, two reference voltage sources Vr1,
Vr2 and one flip-flop FF. A timing resistor 29 and an oscillation capacitor 31 are connected to the terminals T1 and T2. When the oscillation capacitor 31 periodically repeats charging and discharging, the voltage VCT between both terminals of the oscillation capacitor 31 changes with a constant gradient, and a triangular wave is obtained. Note that transistors Q1, Q2
, Q3 and the resistors R1, R2, R3 constitute a charging circuit, and the transistors Q4, Q5 and the resistors R4, R5 constitute a discharging circuit. The control circuit portion of the transistors 5 and 6 of the DC converters 1 and 2 in FIG. 2 includes M51995 sold by Mitsubishi Electric Corporation as a control IC or MB3769A or M3 sold by Fujitsu Limited.
B3770 is used. Note that the second triangular wave generation circuit 28 is also formed in the same manner as in FIG.

Since the frequency of the triangular wave obtained from the triangular wave generating circuit 27 is determined by the product of the resistance value Rt of the timing resistor 29 and the capacitance value Ct of the oscillation capacitor 31, the timing resistor connected to the second triangular wave generating circuit 28 is used. 3
0 and the value of the oscillation capacitor 32 are the same Rt, C
Set to t. Thus, the first and second triangular waves W1 and W2 are generated from the first and second triangular wave generating circuits 27 and 28 at the same frequency as shown in FIG. By the way, when the first and second triangular wave generation circuits 27 and 28 start operating, the phases of the first and second triangular waves W1 and W2 do not always match. Further, the triangular wave voltages may not match even after the operation starts. However, the first and second resistors 33 and 34 and the first and second amplifiers 35 and 3
By the operation of 6, the first and second triangular waves W1, W2 can be synchronized. For example, as shown at time t1 in FIG. 3, the voltage of the first triangular wave W1 based on the first capacitor 31 is changed to the second triangular wave W based on the second oscillation capacitor 32.
2, the output voltage of the first amplifier 35 becomes higher than the output voltage of the second amplifier 36, so that the first amplifier 35, the second resistor 34, and the second oscillation capacitor In the circuit 32, the charging of the second oscillation capacitor 32 occurs, the discharge speed of the second oscillation capacitor 32 decreases, and the voltage of the second oscillation capacitor 32 becomes the voltage of the first oscillation capacitor 31. Get closer. Further, t2 in FIG.
As shown at the time, when the voltage of the first triangular wave W1 is lower than the voltage of the second triangular wave W2, the output voltage of the second amplifier 36 becomes higher than the output voltage of the first amplifier 35, so that the second The first oscillation capacitor 31 is charged by a circuit including the amplifier 36, the first resistor 33, and the first oscillation capacitor 31, and the charge is added to the charge based on the transistor Q3 in FIG. As a result, the first and second oscillation capacitors 31, 32
And the voltages of the second triangular waves W1 and W2 match, and the first and second DC converters 1 and 2 enter a synchronous operation state.

If the oscillation capacitor 32 of the second DC converter 2 is short-circuited or opened for some reason while the first and second DC converters 1 and 2 are operating in parallel, the second triangular wave No triangular wave is generated from the generating circuit 28, and the second DC converter 2 is substantially stopped. However, the first DC converter 1 continues to operate. That is, even if the second oscillation capacitor 32 is short-circuited or opened, the first oscillation capacitor 31 is separated from the second oscillation capacitor 32 by the first and second resistors 33 and 34. The first triangular wave generation circuit 27 continues generating a triangular wave. Therefore, it is possible to prevent the worst case in which the entire power supply stops.

[0013]

Second Embodiment Next, a DC power supply according to a second embodiment will be described with reference to FIG. However, FIG. 4 and FIG.
In FIG. 10 to FIG. 10, substantially the same parts as those in FIG. The DC power supply shown in FIG. 4 has a first resistor instead of the first and second resistors 33 and 34 shown in FIG.
The structure is the same as that of FIG. 1 except that the second diodes D1 and D2 are connected. The first diode D1 has a direction in which a current flows from the second oscillation capacitor 32 to the first oscillation capacitor 31 (first direction).
The second diode D2 has a direction in which a current flows in a second direction opposite to the first direction. The directionality of the first and second diodes D1 and D2 is determined by the first and second amplifiers 3.
The direction is opposite to the directions of 5, 36.

First and second oscillation capacitors 3 shown in FIG.
When the triangular waves W1 and W2 obtained from the first and the second 32 have the relationship at the time t1 in FIG. 3, the first amplifier 35, the second diode D2, and the second oscillation capacitor 32 provide the second circuit.
Of the oscillation capacitor 32 is charged. As a result, the discharge rate of the second oscillation capacitor 32 decreases, and this voltage approaches the voltage of the first oscillation capacitor 31. When the second triangular wave W2 is higher than the first triangular wave W1 as at time t2 in FIG.
The first oscillating capacitor 31 is charged by the circuit of the diode D1 and the first oscillating capacitor 31, and the charging current flows in addition to the charging current supplied from the charging circuit including the transistor Q3 in FIG. The speed increases, and the voltage of the first oscillation capacitor 31 approaches the voltage of the second oscillation capacitor 32. As a result, the same effect as in the first embodiment can be obtained in the second embodiment.

[0015]

Third Embodiment A DC power supply according to a third embodiment shown in FIG. 5 has first and second transistors 37 and 36 as or instead of the first and second amplifiers 35 and 36 in FIG. , 3
8 except that first and second diodes D1 and D2 are provided in place of the first and second resistors 33 and 34 as in FIG. The first and second transistors 37 and 38 are both NPN type,
These bases are composed of first and second diodes D1, D2.
, And their emitters are connected to the anodes (second terminals) of the first and second diodes D1 and D2, and their collectors are connected to the power supply terminal + Vcc. ing. It should be noted that the first and second transistors 37 and 38 have the first and second diodes D1 and D2 so that the direction of the PN junction between the base and the emitter is opposite to that of the first and second diodes D1 and D2. Transistor 3
7, 38 are connected.

First and second oscillation capacitors 3 shown in FIG.
When the voltages of the first and second oscillator capacitors 31 and 32 are higher than the voltage of the second oscillator capacitor 32 when the voltages of the first and second oscillator capacitors 31 and 32 are at the time point t1 in FIG.
Is forward-biased to turn on the first transistor 37, and the second transistor 37 is turned on by the circuit including the power supply terminal + Vcc, the first transistor 37, the second diode D2, and the second oscillation capacitor 32. The charging current flows through the oscillation capacitor 32, and the discharge of the second oscillation capacitor 32 is delayed, so that the voltage of the second oscillation capacitor 32 approaches the voltage of the first oscillation capacitor 31. Also,
The voltage of the first and second oscillation capacitors 31 and 32 in FIG. 5 is at the time t2 in FIG.
When the voltage of the second transistor 38 is higher than the voltage of the first oscillation capacitor 31, the base-emitter of the second transistor 38 is forward-biased, and the second transistor 38 is turned on. Therefore, the first oscillation capacitor 31 is charged by the circuit of the power supply terminal + Vcc, the second transistor 38, the first diode D1, and the first oscillation capacitor 31,
The voltage of the first oscillation capacitor 31 approaches the voltage of the second oscillation capacitor 32. Therefore, the same effects as in the first embodiment can be obtained by the third embodiment.

[0017]

Fourth Embodiment A DC power supply according to a fourth embodiment shown in FIG. 6 includes first and second diodes D1 and D2 shown in FIG.
The configuration is the same as that of FIG. 5 except that the second resistor 33 and the second resistor 33 are replaced. First and second resistors 3 in FIG.
3, 34 are the first and second diodes D1, D2 of FIG.
Since the fourth embodiment has the same function as that of the first embodiment, the same operation and effect as those of the first and third embodiments can be obtained in the fourth embodiment.

[0018]

Fifth Embodiment A DC power supply according to a fifth embodiment shown in FIG. 7 is configured such that the directions of the first and second diodes D1 and D2 in FIG. Transistor 3
Instead of PNP transistors 7 and 38, first and second PNP transistors 39 and 40 are provided, and their collectors are connected to ground. The anodes of the first and second diodes D1 and D2 have the first
And the bases of the second transistors 39 and 40 are connected, and the emitter is connected to the cathode.

First and second oscillation capacitors 3 shown in FIG.
When the voltages of the first and second capacitors 31 and 32 are at the time point t1 in FIG. 3 and the voltage of the first oscillation capacitor 31 is higher than the voltage of the second capacitor 32, that is, when W1> W2, the second transistor 40 Is in a forward bias state, and the second transistor 40 is turned on. As a result, the circuit of the first oscillation capacitor 31, the first diode D1, and the second transistor 40 becomes an additional discharge circuit of the first oscillation capacitor 31, and the voltage of the first oscillation capacitor 31 is reduced. The voltage drops so as to approach the voltage of the second oscillation capacitor 32. At time t2 in FIG. 3, since the voltage of the second oscillation capacitor 32 is higher than the voltage of the first oscillation capacitor 31, the emitter-base of the first transistor 39 is forward-biased and the first Transistor 39 is turned on. As a result, the circuit including the second oscillation capacitor 32, the second diode D2, and the first transistor 39 becomes an additional discharge circuit of the second oscillation capacitor 32, and the voltage of the second oscillation capacitor 32 Decrease so as to approach the voltage of the first oscillation capacitor 31. Accordingly, the same effects as those of the first and third embodiments can be obtained by the fifth embodiment.

[0020]

Sixth Embodiment A DC power supply according to a sixth embodiment shown in FIG. 8 includes first and second diodes D1 and D2 shown in FIG.
The configuration is the same as that shown in FIG. 7 except that the first and second resistors 33 and 34 are replaced. First and second resistors 3 in FIG.
Reference numerals 3 and 34 denote the first and second diodes D1 and D2 in FIG.
Since the sixth embodiment has the same function as that of the fifth embodiment, the sixth embodiment has the same effect as the fifth embodiment.

[0021]

Seventh Embodiment A DC power supply according to a seventh embodiment shown in FIG. 9 has an NPN circuit in place of the first and second resistors 33 and 34 and the first and second amplifiers 35 and 36 in FIG. The structure is the same as that of FIG. 1 except that a first transistor 41 of a PNP type, a second transistor 42 of a PNP type and a resistor 43 are provided.
The bases of the first and second transistors 41 and 42 are the first
Are connected to the triangular wave output side terminal of the oscillation capacitor 31, and their emitters are connected to the triangular wave output side terminal of the second oscillation capacitor 32. The collector of the first transistor 41 is connected to the power supply terminal + Vcc,
The collector of the second transistor 42 is connected to the ground. The resistor 43 is connected between the bases and the emitters of the first and second transistors 41 and 42.

First and second oscillation capacitors 3 shown in FIG.
When the voltages of the first and second oscillation capacitors 31 and 32 are higher than the voltage of the second oscillation capacitor 32 when the voltages of the first and second oscillation capacitors 31 and 32 are in the state at time t1 in FIG.
Is forward-biased, and the first transistor 41 is turned on. As a result, the power supply terminal + Vcc, the first transistor 41 and the second oscillation capacitor 32
In the circuit described above, the charging current flows through the second oscillation capacitor 32, and the discharge rate of the second oscillation capacitor 32 decreases,
The voltage of the second oscillation capacitor 32 approaches the first oscillation capacitor 31. When the voltage of the second oscillation capacitor 32 is higher than the voltage of the first oscillation capacitor 31, as at time t2 in FIG. 3, the base-emitter of the second transistor 42 is forward-biased, The second transistor 42 is turned on. As a result, the discharging circuit of the second oscillation capacitor 32 is formed by the second transistor 42, the charging speed of the voltage of the second oscillation capacitor 32 is reduced, and the voltage of the second oscillation capacitor 32 becomes the second oscillation capacitor. 1 approaches the voltage of the oscillation capacitor 31. Therefore, the seventh embodiment also has the same effect as the first embodiment. The resistor 43 is provided for stabilization and can be omitted.

[0023]

Eighth Embodiment FIG. 9 shows a DC power supply according to an eighth embodiment of the present invention.
It has the same configuration as that of FIG. 9 except that a fourth transistor 45 and a second resistor 46 are added. Third and fourth
The bases of the transistors 44 and 45 are connected to the triangular wave output side terminal of the second oscillation capacitor 32, and their emitters are connected to each other and connected to the first and second emitters. The collector of the third transistor 44 is connected to the power supply terminal + Vcc, and the collector of the fourth transistor 45 is connected to the ground. The second resistor 46 is connected between the emitter and the base of the third and fourth transistors 44, 45.

When the voltage of the first oscillation capacitor 31 in FIG. 10 is higher than the voltage of the second oscillation capacitor 32 as shown at the time point t1 in FIG. 3, the first and fourth transistors 41 and 45 are turned off. Turns on, the fourth transistor 4
The second oscillation capacitor 32 is charged by the base current of No. 5. Conversely, as shown at time t2 in FIG. 3, the voltage of the second oscillation capacitor 32 is changed to the first oscillation capacitor 31.
, The second and third transistors 42 and 44 are turned on, and the first oscillation capacitor 31 is charged with the base current of the second transistor 42.
Thereby, the first and second oscillation capacitors 31, 3
2 become the same. The transistors 41, 4
2, 44 and 45 operate in the unsaturated region. According to the eighth embodiment, the same effect as that of the first embodiment can be obtained.

[0025]

[Modifications] The present invention is not limited to the above-described embodiment, and for example, the following modifications are possible. (1) As shown in FIG. 11, the third triangular wave generation circuit 47
, A timing resistor 48 and a third oscillation capacitor 49 are connected to the third triangular wave generation circuit 4.
7 in the third DC converter and three parallel connections of the first and second DC converters and first and second DC converters incorporating the first and second triangular wave generating circuits 27 and 28. It can be configured. In this case, a parallel circuit of the third resistor 50 and the third amplifier 51 is connected to the triangular wave output side terminal of the third oscillation capacitor 49. Also, one end of a parallel circuit of a first resistor 33 and a first amplifier 35, one end of a parallel circuit of a second resistor 34 and a second amplifier 36, and a parallel circuit of a third resistor 50 and a third amplifier 51. To one end. With the configuration as shown in FIG. 11, the voltages of the first, second, and third oscillation capacitors 31, 32, and 49 become the same, and the first, second, and third DC converters can be operated synchronously. Become. (2) In the embodiment of FIGS. 4 to 10, three or more DC converters can be modified so as to operate synchronously as in the case of FIG. (3) A diode can be added in series with the resistors 33 and 34 in FIG. 1 in the same direction as in FIG. That is, a resistor can be connected in series with the diodes D1 and D2 in FIG. (4) In FIGS. 5 and 7, a resistor can be connected in series to the first and second diodes D1 and D2. (5) A current limiting resistor is connected in series to the second transistor 42 in FIG. 9 and the second and fourth transistors 42 and 45 in FIG. 10, and the first and second transistors 41 and 41 in FIG. , 42 and the emitters of the third and fourth transistors 44, 45 in series. (6) The DC converters 1 and 2 are not limited to the type shown in FIG. 1, but may be another type. For example, a chopper circuit that performs PWM control may be used. Also, PW
A DC converter including an M inverter may be used. (7) The triangular wave generation circuits 27 and 28 are not limited to the circuit shown in FIG. 2 and can be variously modified. That is, any circuit may be used as long as a charging circuit and a discharging circuit are connected to the capacitor and a triangular wave is generated by charging and discharging the capacitor.

[Brief description of the drawings]

FIG. 1 is a circuit diagram illustrating a DC power supply device according to a first embodiment.

FIG. 2 is a circuit diagram illustrating a triangular wave generation circuit of FIG. 1 in detail.

FIG. 3 is a waveform diagram showing a relationship between two triangular waves in the DC power supply device of FIG.

FIG. 4 is a circuit diagram showing a DC power supply device according to a second embodiment.

FIG. 5 is a circuit diagram showing a DC power supply device according to a third embodiment.

FIG. 6 is a circuit diagram illustrating a DC power supply device according to a fourth embodiment.

FIG. 7 is a circuit diagram showing a DC power supply device according to a fifth embodiment.

FIG. 8 is a circuit diagram showing a DC power supply device according to a sixth embodiment.

FIG. 9 is a circuit diagram showing a DC power supply device according to a seventh embodiment.

FIG. 10 is a circuit diagram showing a DC power supply device according to an eighth embodiment.

FIG. 11 is a circuit diagram showing a triangular wave generating portion of a modification.

[Explanation of symbols]

 1, 2 First and second DC converters 31, 32 First and second oscillation capacitors 33, 34 First and second resistors 35, 26 First and second amplifiers

Claims (8)

[Claims] 1. At least a first and a second connected in parallel
Each of the first and second DC converters includes a switching element for controlling a voltage level, a triangular wave generating circuit, and the switching element based on an output of the triangular wave generating circuit. A control pulse forming circuit for forming a control pulse for turning on / off the triangular wave, the triangular wave generating circuit includes a capacitor for obtaining a triangular wave, a charging circuit and a discharging circuit for the capacitor, and the first And a series circuit of first and second resistors is connected between the triangular wave output side terminals of the capacitor of the second DC converter and has a first direction in parallel with the first resistor. A DC power supply device, wherein a first amplifier is connected, and a second amplifier is connected in parallel with the second resistor with a second direction opposite to the first direction. . 2. At least a first and a second connected in parallel
Each of the first and second DC converters includes a switching element for controlling a voltage level, a triangular wave generating circuit, and the switching element based on an output of the triangular wave generating circuit. A control pulse forming circuit for forming a control pulse for turning on / off the triangular wave, the triangular wave generating circuit includes a capacitor for obtaining a triangular wave, a charging circuit and a discharging circuit for the capacitor, and the first And a first diode having a first direction and a second diode having a second direction opposite to the first direction between the triangular wave output terminals of the capacitor of the second DC converter. Is connected in series with the first diode and has the second directivity in the first direction.
And a second amplifier having the first directivity and connected in parallel with the second diode. 3. At least a first and a second connected in parallel
Each of the first and second DC converters includes a switching element for controlling a voltage level, a triangular wave generating circuit, and the switching element based on an output of the triangular wave generating circuit. A control pulse forming circuit for forming a control pulse for turning on / off the triangular wave, the triangular wave generating circuit includes a capacitor for obtaining a triangular wave, a charging circuit and a discharging circuit for the capacitor, and the first And a first diode having a first direction and a second diode having a second direction opposite to the second direction between the triangular wave output terminals of the capacitor of the second DC converter. A series circuit with a diode is connected, comprising a first and a second transistor, wherein a base of the first transistor is connected to one terminal of the first diode; The emitter of the first transistor is connected to the other terminal of the first diode, the collector of the first transistor is connected to the power supply, P between the base and emitter of said first transistor
The polarity of the first transistor is determined such that the direction of the N junction is opposite to the direction of the PN junction of the first diode, and the base of the second transistor is connected to one terminal of the second diode. Connected, the emitter of the second transistor is connected to the other terminal of the second diode, the collector of the second transistor is connected to the power supply, and the P-to-E between the base and the emitter of the second transistor is connected.
A DC power supply device, wherein the polarity of the second transistor is determined such that the direction of the N junction is opposite to the direction of the PN junction of the second diode. 4. The DC power supply according to claim 3, wherein first and second resistors are connected in place of said first and second diodes. 5. At least a first and a second connected in parallel
Each of the first and second DC converters includes a switching element for controlling a voltage level, a triangular wave generating circuit, and the switching element based on an output of the triangular wave generating circuit. A control pulse forming circuit for forming a control pulse for turning on / off the triangular wave, the triangular wave generating circuit includes a capacitor for obtaining a triangular wave, a charging circuit and a discharging circuit for the capacitor, and the first And a first diode having a first direction and a second diode having a second direction opposite to the first direction between the triangular wave output terminals of the capacitor of the second DC converter. And a series circuit of the first and second transistors is connected, and a base of the first transistor is connected to one terminal of the first diode. An emitter of the first transistor is connected to the other terminal of the first diode; a collector of the first transistor is connected to a ground terminal of the capacitor of the first DC converter; Is connected to one terminal of the second diode, the emitter of the second transistor is connected to the other terminal of the second diode, and the collector of the second transistor is connected to the second DC terminal. Connected to the ground side terminal of the capacitor of the conversion device, and the direction of the PN junction between the base and the emitter of the first and second transistors is set to the P of the first and second diodes.
A DC power supply device, wherein the polarities of the first and second transistors are determined so as to be opposite to the direction of the N junction. 6. The DC power supply according to claim 5, wherein first and second resistors are connected in place of the first and second diodes. 7. At least a first and a second connected in parallel
Each of the first and second DC converters includes a switching element for controlling a voltage level, a triangular wave generating circuit, and the switching element based on an output of the triangular wave generating circuit. A control pulse forming circuit for forming a control pulse for turning on / off the triangular wave, the triangular wave generating circuit includes a capacitor for obtaining a triangular wave, a charging circuit and a discharging circuit for the capacitor, and the first And an NPN-type first transistor and a PNP-type second transistor are connected between the triangular-wave output terminals of the capacitor of the second DC converter, and the base of the first transistor is 1, connected to a triangular wave output terminal of the capacitor of the DC converter;
The emitter of the first transistor is connected to a triangular-wave output terminal of a capacitor of the second DC converter, the collector of the first transistor is connected to a power supply, and the base of the second transistor is connected to the first transistor. Is connected to the triangular-wave output terminal of the capacitor of the DC converter, the emitter of the second transistor is connected to the triangular-wave output terminal of the capacitor of the second DC converter, and the collector of the second transistor is A DC power supply device, wherein the DC power supply device is connected to a ground terminal of the capacitor of the first and second DC converters. 8. At least a first and a second connected in parallel
Each of the first and second DC converters includes a switching element for controlling a voltage level, a triangular wave generating circuit, and the switching element based on an output of the triangular wave generating circuit. A control pulse forming circuit for forming a control pulse for turning on / off the triangular wave, the triangular wave generating circuit includes a capacitor for obtaining a triangular wave, a charging circuit and a discharging circuit for the capacitor, and the first And an NPN-type first transistor, a PNP-type second transistor, an NPN-type third transistor, and a PNP-type fourth transistor between the triangular-wave output terminals of the capacitor of the second DC converter. And the bases of the first and second transistors are connected to a triangular wave output terminal of the capacitor of the first DC converter. Respectively connected, the emitters of the first and second transistors are connected to each other, the collector of the first transistor is connected to a power supply, and the collector of the second transistor is connected to the first and second DC converters. And the bases of the third and fourth transistors are connected to the triangular wave output side terminal of the capacitor of the second DC converter, respectively, and the third and fourth transistors are connected to each other. Are connected to each other and to the emitters of the first and second transistors, the collector of the third transistor is connected to a power supply, and the collector of the fourth transistor is connected to the first and second transistors. 2. A DC power supply, wherein the DC power supply is connected to a ground terminal of the capacitor of the DC converter.