WO2013124921A1 - 直流電源回路 - Google Patents
直流電源回路 Download PDFInfo
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- WO2013124921A1 WO2013124921A1 PCT/JP2012/006656 JP2012006656W WO2013124921A1 WO 2013124921 A1 WO2013124921 A1 WO 2013124921A1 JP 2012006656 W JP2012006656 W JP 2012006656W WO 2013124921 A1 WO2013124921 A1 WO 2013124921A1
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
- H05B45/37—Converter circuits
- H05B45/3725—Switched mode power supply [SMPS]
- H05B45/385—Switched mode power supply [SMPS] using flyback topology
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/14—Arrangements for reducing ripples from dc input or output
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/42—Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/42—Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
- H02M1/4208—Arrangements for improving power factor of AC input
- H02M1/4225—Arrangements for improving power factor of AC input using a non-isolated boost converter
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
- H02M3/1563—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators without using an external clock
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
- H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
- H02M7/06—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes without control electrode or semiconductor devices without control electrode
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
- H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
- H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/21—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/217—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
- H05B45/37—Converter circuits
- H05B45/3725—Switched mode power supply [SMPS]
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
- H05B45/37—Converter circuits
- H05B45/3725—Switched mode power supply [SMPS]
- H05B45/375—Switched mode power supply [SMPS] using buck topology
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
Definitions
- the present invention relates to a DC power supply circuit, and more particularly to a technique for improving the power factor of the circuit.
- LEDs light-emitting diodes
- a DC power source is necessary.
- Patent Document 1 discloses a DC power supply circuit comprising a diode bridge, a smoothing capacitor connected between the output ends of the diode bridge, and a voltage conversion circuit that converts and outputs a voltage between both ends of the smoothing capacitor. Is described.
- the current from the AC power source flows into the smoothing capacitor through the diode bridge because the output voltage of the diode bridge is at both ends of the smoothing capacitor. It is only the period when it becomes higher than the voltage between.
- the maximum charging voltage of the capacitor is equal to the maximum value of the output voltage of the rectifier circuit. Therefore, in one cycle of AC supplied from the AC power supply, the voltage across the capacitor is higher than the output voltage of the rectifier circuit in the 1/4 cycle after the output voltage of the diode bridge reaches the maximum value. As a result, the current flowing from the AC power supply to the capacitor via the rectifier circuit is cut off. For this reason, the power factor given by the inner product of voltage and current corresponds to only the first half of each half cycle of alternating current, and is a low value of about 0.5.
- the present invention has been made in view of the above reasons, and an object thereof is to provide a DC power supply circuit capable of improving the power factor.
- a DC power supply circuit includes a rectifier circuit that rectifies AC supplied from an AC power supply, and a load that is connected between the output terminals of the rectifier circuit and that converts an input voltage from the rectifier circuit and is connected to the output terminal.
- the voltage conversion circuit includes a capacitor having one end connected to the output terminal on the low potential side of the rectifier circuit, and a discharge current path from the capacitor extending from the other end of the capacitor to one end of the capacitor.
- a series circuit composed of an inductor and a switching element inserted in the middle of the capacitor, one end connected to the switching element in the inductor and the other end of the capacitor, and charging the current from the inductor toward the other end of the capacitor
- the output terminal on the high potential side of the rectifier circuit is connected to the other end of the inductor, and the voltage conversion circuit is in each half cycle of the alternating current.
- the second period during which current flows through the second current path from the output terminal on the high potential side of the rectifier circuit to the output terminal on the low potential side of the rectifier circuit via the inductor, the charging current supply path and the capacitor is alternated several times.
- the first period current flows through the first current path from the high-potential side output terminal of the rectifier circuit to the low-potential side output terminal of the rectifier circuit via the inductor and the switching element.
- the voltage conversion circuit current flows in a second current path from the output terminal on the high potential side of the rectifier circuit to the output terminal on the low potential side of the rectifier circuit via the inductor, the charging current supply path and the capacitor.
- the first period and the second period alternately come a plurality of times, so that the current continues to flow from the rectifier circuit to the voltage conversion circuit in almost the entire half period of the alternating current. The power factor seen from the power supply side becomes high.
- FIG. 2 is a circuit diagram of a DC power supply circuit according to Embodiment 1.
- FIG. FIG. 2 is a circuit diagram showing a DC power supply circuit according to Embodiment 1, and a diagram showing a current flow in the DC power supply circuit.
- (a) is a diagram illustrating an on / off operation of the switching element
- (b) is a diagram illustrating a time waveform of a current flowing through the inductor
- (c) is a diagram illustrating The time waveform of the voltage which arises in the connection point of an inductor is shown
- (d) is a figure which shows the time waveform of the electric current which flows into a diode.
- (A) is a figure which shows the time waveform of the input voltage from an AC power supply to a rectifier circuit in the direct-current power supply circuit which concerns on Embodiment 1
- (b) shows the time waveform of the voltage between the both ends of a capacitor
- (C) is a figure which shows the time waveform of the voltage of the connection point of an inductor
- (d) is a figure which shows the time waveform of the electric current which flows into an rectifier circuit from AC power supply.
- (A) is a figure which shows the time waveform of the input voltage from AC power supply AC to the rectifier circuit 2 in the DC power supply circuit which concerns on Embodiment 1
- (b) is the time of the voltage between the both ends of the capacitor
- FIG. 6 is a circuit diagram of a DC power supply circuit according to Embodiment 2.
- FIG. 6 is a diagram for explaining the operation of a DC power supply circuit according to Embodiment 2.
- FIG. 4 is a circuit diagram showing a DC power supply circuit according to Embodiment 2 and a diagram showing a current flow in the DC power supply circuit.
- FIG. 4 is a circuit diagram showing a DC power supply circuit according to Embodiment 2 and a diagram showing a current flow in the DC power supply circuit.
- FIG. 4 is a circuit diagram showing a DC power supply circuit according to Embodiment 2 and a diagram showing a current flow in the DC power supply circuit.
- FIG. 4 is a circuit diagram showing a DC power supply circuit according to Embodiment 2 and a diagram showing a current flow in the DC power supply circuit.
- (a) is a diagram illustrating an on / off operation of the switching element
- (b) is a diagram illustrating a time waveform of a current flowing through the inductor
- (c) is a diagram illustrating It is a figure which shows the time waveform of the electric current which flows into a diode.
- (a) is a diagram showing a time waveform of the output voltage of the rectifier circuit
- (b-1) and (b-2) are the inductors and diodes in the P period.
- FIG. 4 is a diagram illustrating a time waveform of a flowing current
- (c-1) and (c-2) are diagrams illustrating a time waveform of a current flowing through an inductor and a diode in a Q period.
- (A) is a figure which shows the time waveform of the input voltage from AC power supply to a rectifier circuit in the DC power supply circuit which concerns on Embodiment 2
- (b) is a figure which shows the time waveform of the output voltage of a rectifier circuit.
- C) is a figure which shows the time waveform of the electric current which flows through a diode
- (d) is a figure which shows the time waveform of the electric current which flows into an rectifier circuit from AC power supply.
- (a-1) is a diagram showing a time waveform of the current flowing through the inductor when operating in the critical mode
- (a-2) is operating in the critical mode
- FIG. 5B is a diagram illustrating a time waveform of a voltage generated at a connection point of two inductors in the case where the current flows through the inductor when operating in a continuous mode
- (B-2) is a diagram showing a time waveform of a voltage generated at a connection point of two inductors when operating in the continuous mode.
- (a) shows the time waveform of the input voltage from the AC power supply to the rectifier circuit
- (b) shows the time waveform of the voltage across the capacitor
- (c) shows The time waveform of the voltage of the connection point of an inductor is shown
- (d) shows the time waveform of the electric current which flows into an rectifier circuit from AC power supply.
- FIG. 1 shows a circuit diagram of a DC power supply circuit 1 according to the present embodiment.
- the DC power supply circuit 1 includes a rectifier circuit 2 connected to an AC power supply AC, a voltage conversion circuit 3 connected to the output terminal of the rectifier circuit 2, and a drive circuit U1 for driving the voltage conversion circuit 3. Yes.
- the DC power supply circuit 1 also includes a constant voltage circuit 4 for supplying power to the drive circuit U1.
- the load 11 formed by connecting a plurality of LEDs in series is connected to the output end of the voltage conversion circuit 3.
- the voltage across the load 11 is determined by the number of LEDs constituting the load 11. This is different from a load having a resistive impedance such as a fluorescent lamp.
- a current limiting resistor R1 is connected between the AC power source AC and the rectifier circuit 2 in order to prevent an overcurrent from flowing from the AC power source AC to the rectifier circuit 2.
- the rectifier circuit 2 is composed of a diode bridge composed of four diodes.
- a capacitor C1 is connected between the output terminals of the rectifier circuit 2 in order to block high-frequency noise.
- the capacitor C1 is composed of, for example, an electrolytic capacitor, a high dielectric constant ceramic capacitor, a film capacitor, or the like.
- the voltage conversion circuit 3 constitutes a booster circuit, and includes a switching element Q1, an inductor (inductor) L2, an inductor (auxiliary inductor) L3, diodes D1 and D2, and a capacitor. C2 and C4 and a resistor R2.
- the switching element Q1 is composed of an N-channel MOSFET, and has a source connected to the output terminal on the low potential side of the rectifier circuit 2 via the resistor R2, a gate connected to the drive circuit U1 via the resistor R11, and a drain. Is connected to the inductor L2.
- the resistor R2 is for detecting the drain current flowing through the switching element Q1 based on the voltage generated between both ends.
- the diode D2 has an anode connected to the output terminal on the high potential side of the rectifier circuit 2, and a cathode connected to the other end of the inductor L2. In the diode D2, when no current flows through the inductors L2 and L3 and the potential at the connection point of the inductors L2 and L3 becomes higher than the potential on the high potential side of the capacitor C1, the current flows from the other end of the inductor L2 to the capacitor C1. This is to prevent reverse flow.
- the diode D1 is inserted in a charging current supply path that supplies a charging current to the capacitor C2 from between the inductor L2 and the switching element Q1.
- the diode D1 has an anode commonly connected to the one end of the inductor L2 and the drain of the switching element Q1, and a cathode connected to the capacitor C2.
- One end of the capacitor C2 is connected to the output terminal on the low potential side of the rectifier circuit 2, and the other end is connected to the cathode of the diode D1.
- One end of the capacitor C4 is connected to the cathode of the diode D1, and the other end is connected to the other end of the inductor L3.
- the current path from the other end of the capacitor C2 to the one end of the capacitor C2 through the load 11, the inductor L3, the inductor L2, the switching element Q1, and the resistor R1 in this order forms the discharge current path of the capacitor C2. .
- the voltage conversion circuit 3 outputs a voltage across the capacitor C4 to the load 11 connected in parallel with the capacitor C4.
- the capacitor C2 is composed of, for example, an electrolytic capacitor, a high dielectric constant ceramic capacitor, a film capacitor, or the like.
- the drive circuit U1 outputs a control signal (hereinafter referred to as a “PWM signal”) having a rectangular wave voltage waveform for driving the switching element Q1 by PWM (Pulse Width Modulation) control. .
- PWM Pulse Width Modulation
- the drive circuit U1 includes a power supply terminal te0, an output terminal te1, a ground terminal te2, and a current detection terminal te3 for detecting a drain current flowing through the switching element Q1.
- the power supply terminal te0 is connected between the output terminals of the constant voltage circuit 4.
- the ground terminal te2 is connected to the output terminal on the low potential side of the rectifier circuit 2.
- the output terminal te1 is connected to the gate of the switching element Q1 via the resistor R11.
- the current detection terminal te3 is connected between the source of the switching element Q1 and the resistor R2.
- This drive circuit U1 inputs a PWM signal to the gate of the switching element Q1. Then, the pulse width of the PWM signal is adjusted so that the drain current flowing through the switching element Q1 detected by the current detection terminal te3 is constant.
- the pulse width of the PWM signal is changed, the gate voltage of the switching element Q1 is changed to the ON voltage of the switching element Q1 (hereinafter, “the ON voltage of the switching element Q1” is necessary to turn on the switching element Q1.
- the period during which the above voltage is maintained and the period during which the gate voltage of the switching element Q1 is maintained at a voltage lower than the ON voltage of the switching element Q1 varies. To do.
- a period during which the switching element Q1 is maintained in the on state is referred to as an “on period”.
- a period during which the gate voltage of the switching element Q1 is maintained at approximately 0V, that is, the period during which the switching element Q1 is maintained in the off state is referred to as an “off period”.
- the ratio of the on period within one cycle of the on / off operation of the switching element Q1 is referred to as “on duty”. Then, the drive circuit U1 drives the switching element Q1 by constant current control by changing the on-duty.
- the constant voltage circuit 4 includes resistors R41 and R42, a capacitor C43, and a Zener diode ZD44.
- the resistors R41 and R42 are connected in series between the output terminals of the rectifier circuit 2.
- One end of the resistor R41 is connected to the output terminal on the high potential side of the rectifier circuit 2
- the resistor R42 is connected between the other end of the resistor R41 and the output terminal on the low potential side of the rectifier circuit 2.
- the capacitor C43 is connected between both ends of the resistor R42.
- the Zener diode ZD44 has an anode connected to the output terminal on the low potential side of the rectifier circuit 2, a cathode connected to a connection point between the resistors R41 and R42, and a power supply terminal te0 of the drive circuit U1. Thereby, the potential of the power supply terminal te0 of the drive circuit U1 is maintained at a constant potential generated at the cathode of the Zener diode ZD44.
- the constant voltage circuit 4 further includes a capacitor C47, a resistor R46, and diodes D45 and D48.
- One end of the capacitor C47 is connected to the anode of the diode D1 of the voltage conversion circuit 3.
- the diode D45 has an anode connected to the other end of the capacitor C47 via the resistor R46, and a cathode connected to the power supply terminal te0 of the drive circuit U1.
- the diode D48 has a cathode connected to a connection point between the resistor R46 and the anode of the diode D45, and an anode connected to the output terminal on the low potential side of the rectifier circuit 2. This diode D48 is for discharging the electric charge of the capacitor C47.
- the capacitors C43 and C47 are charged during the period when the switching element Q1 is turned off, and the capacitor C47 is discharged during the period when the switching element Q1 is turned on, so that the charge accumulated in the capacitor C47 is obtained. Is sent to the capacitor C43. With this configuration, power can be supplied from the voltage conversion circuit 3 side to the power supply terminal te0 of the drive circuit U1.
- FIGS. 2A and 2B show a circuit diagram of the DC power supply circuit 1 according to the present embodiment and a current flow in the DC power supply circuit 1.
- FIG. 2A shows the flow of current when the switching element Q1 is on
- FIG. 2B shows the flow of current when the switching element Q1 is off.
- the switching element Q1 when the switching element Q1 is in the ON state (during the first period), the potential at the other end of the inductor L2 is the turn-on voltage of the diode D2 higher than the potential on the high potential side of the rectifier circuit 2. It is lower by the minute. Thereby, the current flowing out from the high potential side of the rectifier circuit 2 passes through the other end of the inductor L2 and the switching element Q1 in this order (hereinafter referred to as “first current”).
- first current a current flowing from the other end of the capacitor C2 passes through the load 11, the inductor L3, the inductor L2, the switching element Q1, and the resistor R2 in this order (hereinafter referred to as “third current path”).
- This third current path corresponds to the discharge path of the capacitor C2.
- magnetic energy is accumulated in the inductors L2 and L3, and at the same time, from the output terminal on the high potential side of the rectifier circuit 2 through the first current path. Therefore, magnetic energy is accumulated in the inductor L2.
- the switching element Q1 when the switching element Q1 is in the OFF state (during the second period), the current flowing out from the output terminal on the high potential side of the rectifier circuit 2 is the inductor L2, the diode D1, the capacitor A path (hereinafter referred to as “second current path”) that reaches the output terminal on the low potential side of the rectifier circuit 2 through the order of C2 is followed.
- the current flowing out from one end of the inductor L2 follows a path (hereinafter referred to as “fourth current path”) that reaches the other end of the inductor L3 via the diode D1 and the load 11 in this order.
- the current flowing through the second current path via the capacitor C2 is cut off when the charging of the capacitor C2 is completed.
- This second current path corresponds to the charging path of the capacitor C2.
- the magnetic energy accumulated in the inductors L2 and L3 is released to the load 11 side by the current flowing through the fourth current path.
- the voltage (second voltage) generated at the other end of the inductor L2 when flowing is set to be equal.
- the on-duty of the switching element Q1 in the drive circuit U1 is set. It is set.
- the voltage generated at the other end of the inductor L2 is set to be lower than a voltage (hereinafter referred to as “voltage threshold”) lower than the output voltage of the rectifier circuit 2 by the turn-on voltage Von of the diode D2. Yes.
- voltage threshold a voltage lower than the output voltage of the rectifier circuit 2 by the turn-on voltage Von of the diode D2.
- the on / off operation of the switching element Q1 is shown in FIG. 3A
- the time waveform of the current IL2 flowing through the inductor L2 is shown in FIG. 3B
- the time waveform is shown in FIG.
- the time waveform of the electric current which flows into the diode D2 is shown in FIG.3 (d).
- the voltage VL at the other end of the inductor L2 is maintained at a voltage Vth that is lower than the voltage across the capacitor C1 by the turn-on voltage of the diode D2 (hereinafter referred to as “voltage threshold”) (FIG. 3).
- Vth is lower than the voltage VC2 when no current flows through the inductors L2 and L3 by the voltage drop VLED at the load 11. Further, the current flowing through the inductor L2 from the output terminal on the high potential side of the rectifier circuit 2 via the diode D2 also gradually increases (period T0 to T1 in FIG. 3D).
- the time waveform of the input voltage from the AC power supply AC to the rectifier circuit 2 is shown in FIG. 4A
- the time waveform of the voltage VC2 across the capacitor C2 is shown in FIG.
- the time waveform of the voltage VL at the other end of L2 is shown in FIG. 4C
- the time waveform of the current Iin flowing into the rectifier circuit 2 from the AC power supply AC is shown in FIG.
- the time waveform of the input voltage from the AC power supply AC to the rectifier circuit 2 has a sine wave shape.
- the timing at which the voltage VC2 across the capacitor C2 reaches the maximum value has a substantially pulsating time waveform, and deviates from the timing at which the absolute value of the input voltage to the rectifier circuit 2 becomes maximum. This is because the capacitance of the capacitor C2 is large and the switching element Q1 cannot be charged up to the maximum charging voltage by one on / off operation of the switching element Q1.
- the voltage threshold Vth is a voltage lower than the voltage across the capacitor C2 by the turn-on voltage Von of the diode D2.
- the voltage at the other end of the inductor L2 is between the voltage VC2-VLED that is lower than the voltage VC2 between both ends of the capacitor C2 by the voltage drop VLED due to the load 11 and the voltage threshold value VTh in the ON / OFF cycle of the switching element Q1. Vibrate.
- the diode D2 continues to be non-conductive, and the voltage conversion circuit 3 side from the AC power supply AC via the rectifier circuit 2 The current flowing in is completely cut off.
- the time waveform of the input voltage from the AC power supply AC to the rectifier circuit 2 is shown in FIG. 5A
- the time waveform of the voltage VC2 across the capacitor C2 is shown in FIG.
- a time waveform of the current Iin flowing from the power source AC to the rectifier circuit 2 is shown in FIG. 5C
- a time waveform of the voltage VC2 across the capacitor C2 is shown in FIG.
- a period Ti in which a current flows from the AC power supply AC to the rectifier circuit 2 and a period Tis in which a current flowing from the AC power supply AC to the rectifier circuit 2 is interrupted alternately arrive.
- the period Ti includes a period in which the current Iin flows from the AC power supply AC to the rectifier circuit 2 even after the absolute value of the input voltage Vs reaches the maximum value in the half cycle of the input voltage Vs. Thereby, after the absolute value of the input voltage Vs reaches the maximum value, the power factor can be improved as compared with the configuration in which there is no period in which the current Iin flows from the AC power supply AC to the rectifier circuit 2.
- the power factor is about 0.56 to 0.61, in the DC power supply circuit 1 according to the present embodiment, the power factor can be 0.8 or more.
- the timing at which the input current Iin from the AC power supply AC to the rectifier circuit 2 becomes maximum is about a quarter cycle from the beginning in the half cycle of the input voltage Vs.
- the timing at which the input current Iin from the AC power supply AC to the rectifier circuit 2 becomes maximum is The timing when the output voltage Vin of the rectifier circuit 2 becomes maximum is approaching.
- the time waveform of the input current In of the DC power supply circuit 1 has better left-right symmetry than the configuration according to the comparative example.
- the DC power supply circuit 1 has a difference between the timing at which the input current Iin from the AC power supply AC to the rectifier circuit 2 becomes maximum and the timing at which the input voltage Vin becomes maximum, as compared with the configuration according to the comparative example.
- the left and right symmetry of the time waveform of the input current Iin is small. Accordingly, the DC power supply circuit 1 has a smaller proportion of harmonic components included in the input current Iin than the configuration according to the comparative example, and accordingly, the harmonics radiated to the outside from the device including the DC power supply circuit 1 are correspondingly reduced. There is an advantage that wave noise can be suppressed.
- the inductances of the inductors L2 and L3 can be changed.
- the current can be increased by increasing the inductor L2.
- the inductor L2 can store a larger amount of energy as its inductance increases, and accordingly, the inductor L2 is considered to increase the force of flowing current from the high potential side of the rectifier circuit 2.
- the first period and the second period alternately come a plurality of times, so that the current continues to flow from the rectifier circuit 2 to the voltage conversion circuit 3 in substantially the entire period of the half cycle of the alternating current.
- the power factor seen from the AC power supply side becomes high.
- the DC power supply circuit 1 has a capacitor regardless of whether the switching element Q1 is on (during the first period) or the switching element Q1 is off (during the second period).
- a current flows from C1 to the inductor L2 via the other end of the inductor L2.
- the voltage across the capacitor C1 can be reduced below the output voltage of the rectifier circuit 2, so that the voltage conversion circuit 3 from the AC power supply AC via the rectifier circuit 2 can be reduced.
- the current supply to the side can be continued. That is, since the period during which current flows from the AC power supply AC to the capacitor C1 via the rectifier circuit 2 can be lengthened, the power factor can be improved accordingly.
- a PFC circuit power factor improving circuit
- the PFC circuit includes a switching element, an inductor, a control IC, and the like.
- the power factor can be improved without providing a separate PFC (Power Factor Correction) circuit.
- the circuit efficiency can be improved by reducing the power loss.
- the DC power supply circuit 2001 includes a rectifier circuit 2 connected to the AC power supply AC, a voltage conversion circuit 2003 connected to the output terminal of the rectifier circuit 2, and a drive circuit U2001 for driving the voltage conversion circuit 2003. Yes.
- the DC power supply circuit 2001 includes a constant voltage circuit 4 for supplying power to the drive circuit U2001.
- the DC power supply circuit 2001 according to the present embodiment is different from the first embodiment in the configuration of the voltage conversion circuit 2003 and the drive circuit U2001.
- symbol is attached
- the voltage conversion circuit 2003 includes switching elements (first and second switching elements) Q1 and Q2, an inductor L2, a diode D2, a diode bridge (current supply circuit) DB, capacitors C2, C3, C4, and C5. And a resistor R2.
- the capacitor C2 has one end connected to the output terminal on the low potential side of the rectifier circuit 2.
- the capacitor C2 is an electrolytic capacitor. Note that the capacitor C2 may be composed of, for example, a high dielectric constant ceramic capacitor or a film capacitor.
- the capacitor (resonance capacitor) C3 has one end connected to the other end of the capacitor C2, and the other end connected to one input end of the diode bridge DB.
- the inductor L2 has one end connected to the connection point of the switching elements Q1 and Q2, and the other end connected to the other input end of the diode bridge DB.
- the switching element (switching element) Q1 is composed of an N-channel MOSFET, the source is connected to the output terminal on the low potential side of the rectifier circuit 2 via the resistor R2, and the gate is connected to the drive circuit U2001 via the resistor R11. In addition, the drain is connected to the inductor L2. Further, the switching element (sub-switching element) Q2 is interposed in a charging current supply path that supplies a charging current to the capacitor C2 from between the inductor L2 and the switching element Q1.
- Switching element Q2 is composed of an N-channel MOSFET, the source is connected to inductor L2 and the drain of switching element Q1, the gate is connected to drive circuit U2001 via resistor R12, and the drain is connected to capacitor C2.
- the resistor R2 is for detecting the drain current flowing through the switching element Q1 based on the voltage generated between both ends.
- the diode D2 has an anode connected to the output terminal on the high potential side of the rectifier circuit 2, and a cathode connected to the connection between the inductor L2 and the diode bridge DB.
- the capacitor C4 is connected between the input ends of the diode bridge DB.
- the capacitor C4 is for smoothing the input voltage to the rectifier circuit 2.
- the diode bridge DB is composed of four diodes Da, Db, Dc, and Dd.
- the cathodes of the diodes Da and Dc are connected to one end of the load 11, and the anodes of the diodes Db and Dd are connected to the other end of the load 11.
- the anodes of the diodes Da and Dc are connected to the cathodes of the diodes Db and Dd, respectively.
- the anode of the diode Da and the cathode of the diode Db are connected to the other end of the capacitor C3.
- the anode of the diode Dc and the cathode of the diode Dd are connected to the other end of the inductor L2.
- the capacitor C5 is connected between the output ends of the diode bridge DB.
- the capacitor C5 is for smoothing the voltage applied to the load 11.
- the drive circuit U2001 outputs a control signal (hereinafter referred to as a “PWM signal”) having a rectangular voltage waveform for driving the first switching element Q1 by PWM (Pulse Width Modulation) control.
- PWM Pulse Width Modulation
- the drive circuit U2001 includes a power supply terminal te0, output terminals te11 and te12, a ground terminal te2, and a current detection terminal te3 for detecting a drain current flowing through the switching element Q1.
- the power supply terminal te0 is connected between the output terminals of the constant voltage circuit 4.
- the ground terminal te2 is connected to the output terminal on the low potential side of the rectifier circuit 2.
- Each of the output terminals te11 and te12 is connected to the gates of the switching elements Q1 and Q2 via the resistors R11 and R12.
- the current detection terminal te3 is connected between the source of the switching element Q1 and the resistor R2.
- the drive circuit U2001 is composed of one integrated circuit.
- the drive circuit U2001 inputs a PWM signal to the gates of the switching elements Q1 and Q2. Then, the pulse width of the PWM signal is adjusted so that the drain current flowing through the switching element Q1 detected by the current detection terminal te3 is constant.
- the signal input to the gate of the switching element Q2 has an opposite phase to the signal input to the gate of the switching element Q1. Thereby, the switching element Q2 operates so as to be turned off when the switching element Q1 is turned on and to be turned on when the switching element Q1 is turned off.
- the ratio of the period during which the gate voltage of the switching element Q1 is maintained at a voltage equal to or higher than the turn-on voltage of the switching element Q1, that is, the period during which the switching element Q1 is maintained in the on state. (Hereinafter referred to as “on-duty”) changes.
- the on-duty of the switching element Q2 also changes.
- the drive circuit U2001 drives the switching element Q1 by constant current control.
- the constant voltage circuit 4 has the same configuration as that of the first embodiment, and the other end of the capacitor C47 whose one end is connected to the resistor R46 is connected to the connection point of the switching elements Q1 and Q2 of the voltage conversion circuit 2003. .
- the capacitors C43 and C47 are charged while the switching element Q1 is turned off and the switching element Q2 is turned on, and the capacitor C47 is discharged while the switching element Q1 is turned on and the switching element Q2 is turned off.
- the charge accumulated in the capacitor C47 is sent to the capacitor C43.
- FIG. 7 shows a timing chart of the on / off operations of the switching elements Q1 and Q2 in the DC power supply circuit 2001.
- a circuit diagram of the DC power supply circuit 2001 and a current flow in the DC power supply circuit 2001 are shown in FIGS.
- period B in which both switching elements Q1 and Q2 are turned off arrives.
- the C period second period
- the D period in which both the switching elements Q1 and Q2 are turned off comes again.
- the A period to the D period are repeated in order.
- the A period and the C period come alternately.
- the switching element Q1 is turned on and the switching element Q2 is turned off
- the switching element Q1 is turned off and the switching element Q2 is turned on.
- period B in which is maintained in an off state.
- the switching element Q1 when the switching element Q1 is turned off and the switching element Q2 is turned on to shift to the A period in which the switching element Q1 is turned on and the switching element Q2 is turned off, the switching element Q1 and the switching element Q2 are turned on. There is a D period in which both are maintained in the off state.
- the B period and the D period exist in order to ensure that at least one of the switching elements Q1, Q2 is turned off. This is because the DC power supply circuit 2001 malfunctions when there is a period in which both the switching elements Q1 and Q2 are on.
- FIG. 8A shows the flow of current during period A when the switching element Q1 is on and the switching element Q2 is off.
- the current flowing out from the output terminal on the high potential side of the rectifier circuit 2 passes through the inductor L2, the switching element Q1, and the resistor R2 to the path (hereinafter referred to as the output terminal on the low potential side of the rectifier circuit 2).
- first current path the current that flows out from the other end of the capacitor C2 passes through the capacitor C3, the diode Da, the load 11, the diode Dd, the inductor L2, the switching element Q1, and the resistor R2 in this order (hereinafter referred to as “capacitor C2”).
- capacitor C2 the capacitor C3
- This third current path corresponds to a discharge current path for discharging the charge stored in the capacitor C2 to the load 11 through the diode bridge DB during the period when the switching element Q1 is turned off and the switching element Q2 is turned on. .
- a current flows from the output terminal on the high potential side of the rectifier circuit 2 through the first current path, and a discharge current flows from the capacitor C2 through the third current path, whereby magnetic energy is accumulated in the inductor L2.
- FIG. 8B shows the current flow during the period B in which both the switching elements Q1 and Q2 are off.
- the potential at the connection point of the inductor L2 and the diode bridge DB is maintained at a voltage lower than the output terminal on the high potential side of the rectifier circuit 2 by the on-voltage Von of the diode D2. Thereafter, the switching element Q2 is turned on.
- FIGS. 9 (a) and 9 (b) show the current flow during the period C in which the switching element Q1 is turned off and the switching element Q2 is turned on.
- the current flowing out from the output terminal on the high potential side of the rectifier circuit 2 passes through the inductor L2, the switching element Q2, and the capacitor C2, and the low potential of the rectifier circuit 2 is reached.
- the path to the output terminal on the side (hereinafter referred to as “second current path”) is followed.
- the current flowing out from one end of the inductor L2 passes through the capacitor C3, the diode Da, the load 11, and the diode Dd in this order (hereinafter referred to as “fourth current path”) to reach the other end of the inductor L2.
- the fourth current path corresponds to an energy discharge path through which the magnetic energy accumulated in the inductor L2 is discharged to the load 11 through the diode bridge DB.
- the current flowing through the second current path is cut off when the charging of the capacitor C2 is completed. And the electric current which flows through a 4th electric current path continues until charge of the capacitor
- the magnetic energy stored in the inductor L2 is released and the capacitor C3 is charged.
- the capacitor C3 when the charging of the capacitor C3 is completed during the period C, the capacitor C3 immediately starts discharging, and the current flowing out from one end of the capacitor C3 is switched to the switching element Q2, the inductor L2, and the diode.
- a path (hereinafter referred to as “fifth current path”) that reaches the other end of the capacitor C3 through Dc, the load 11, and the diode Db is followed.
- FIG. 10 (a) shows the current flow during period D when both of the switching elements Q1 and Q2 are off.
- the current flowing out from one end of the capacitor C3 passes through the capacitor C2, the resistor R2, the free wheel diode of the switching element Q1, the inductor L2, the diode Dc, the load 11, and the diode Db in this order, and then to the other end of the capacitor C3.
- the route to which this occurs (hereinafter referred to as the “C current route”) is followed. Thereafter, the switching element Q1 is turned on.
- FIGS. 10A and 10B show the current flow during a period (period A) in which the switching element Q1 is on and the switching element Q2 is off.
- the current that flows out from one end of the capacitor C3 passes through the capacitor C2, the resistor R2, the switching element Q1, the inductor L2, the diode Dc, the load 11, and the diode Db in this order (path to the other end of the capacitor C3 ( Hereinafter, this is referred to as “sixth current path”.
- magnetic energy is accumulated in the inductor L2 by the current flowing from the capacitor C3 through the sixth current path.
- the capacitor C3 is charged so that one end on the capacitor C2 side is at a lower potential than the other end on the diode bridge DB side.
- the on / off operation of the switching elements Q1 and Q2 is shown in FIG. 11A
- the time waveform of the current IL2 flowing through the inductor L2 is shown in FIG. 11B
- the time waveform of the current ID2 flowing through the diode D2 is shown. Is shown in FIG.
- the capacitor C3 starts to discharge immediately, and the current flowing through the fifth current path gradually increases.
- the current flowing through the inductor L2 flows in a direction opposite to the flowing direction during the period from time T3 to T4 (C period from time T4 to T5 in FIGS. 11A to 11C). At this time, magnetic energy is stored in the inductor L2.
- the capacitors C2 and C3 immediately start discharging, and again, current starts to flow through the first current path and the third current path, and current starts to flow through the inductor L2 and the diode D2.
- a period during which the current ID2 flows through the diode D2 that is, a period during which current flows into the inductor L2 from the output terminal on the high potential side of the rectifier circuit 2 (hereinafter referred to as “current inflow period”) Ti.
- the period in which the current ID2 is cut off that is, the period Ts in which the current flowing into the inductor L2 from the output terminal on the high potential side of the rectifier circuit 2 is cut off alternately.
- the length of the period Ti during which the current ID2 flows through the diode D2 varies depending on the magnitude of the instantaneous value Vin of the output voltage of the rectifier circuit 2.
- the time waveform of the instantaneous value Vin of the output voltage of the rectifier circuit 2 is shown in FIG. 12A, and the time waveform of the current IL2 flowing through the inductor L2 and the current ID2 flowing through the diode D2 in the period P of FIG. 12 (b-1) and (b-2), and the time waveforms of the current IL2 flowing through the inductor L2 and the current ID2 flowing through the diode D2 in the Q period of FIG. 12 (a) are shown in FIG. 12 (c-1) and Shown in (c-2).
- the instantaneous value Vin of the output voltage of the rectifier circuit 2 is higher in the Q period than in the P period.
- Q is larger than the length of the current inflow period Ti (1) in the P period.
- the length of the current inflow period Ti (2) in the period is longer.
- the maximum value ID2max of the current ID2 flowing through the diode D2 is larger in the Q period than in the P period. Reflecting this, the maximum value IL2max of the current IL2 flowing through the inductor L2 is also larger in the Q period than in the P period.
- the cycle and on-duty of the on / off operation of the switching elements Q1 and Q2 are set so that the ratio of the average value of the current inflow period in the cycle is at least larger than 0.65. Thereby, the ratio of the sum total of the current inflow periods in the half cycle of the AC output from the AC power supply AC can be made larger than at least 0.65.
- the time waveform of the input voltage Vs from the AC power supply AC to the rectifier circuit 2 is shown in FIG. 13A
- the time waveform of the output voltage Vin of the rectifier circuit 2 is shown in FIG.
- the time waveform of the current ID2 flowing through D2 is shown in FIG. 13C
- the time waveform of the input current Iin from the AC power supply AC to the rectifier circuit 2 is shown in FIG.
- the input voltage Vs from the AC power supply AC to the rectifier circuit 2 has a sinusoidal time waveform, whereas the output voltage of the rectifier circuit 2 is Vin has a substantially pulsating current waveform that is maximized when the absolute value of the input voltage Vs from the AC power supply AC to the rectifier circuit 2 is maximized.
- the electric current which flows through the diode D2 has a substantially sawtooth-shaped time waveform synchronizing with the ON / OFF operation
- the envelope shape is the rectifier circuit 2 of FIG. It increases as the instantaneous value Vin of the output voltage increases.
- the magnitude of the input current Iin from the AC power source AC to the rectifier circuit 2 is substantially proportional to the magnitude of the current ID2 flowing through the diode D2.
- the absolute value of the envelope shape of the time waveform of the current ID2 flowing through the diode D2 increases as the instantaneous value Vin of the output voltage of the rectifier circuit 2 increases. Then, as shown in FIG. 13D, the absolute value of the envelope shape of the time waveform of the current Iin flowing from the AC power supply AC to the rectifier circuit 2 reflects the envelope shape of the time waveform of the current ID2 flowing through the diode D2. It has become.
- the current Iin continues to flow intermittently from the AC power supply AC to the rectifier circuit 2 over the entire cycle.
- the current Iin can be intermittently supplied from the AC power supply AC to the voltage conversion circuit 2003 through the rectifier circuit 2 in synchronization with the on / off operation of the switching elements Q1 and Q2.
- the current Iin is supplied from the AC power supply AC to the voltage conversion circuit 2003 via the rectifier circuit 2.
- the sum of the periods during which the current flows can be made longer than the half cycle of the alternating current. For this reason, a power factor improvement can be aimed at.
- the electric charge charged in the capacitor C2 is supplied to the load 11 through the third current path.
- the circuit efficiency of the DC power supply circuit 2001 can be improved by the amount that the discharge current from the capacitor C2 is supplied to the load 11.
- the capacitor C2 is repeatedly charged every time the period C in which the switching element Q1 is turned off and the switching element Q2 is turned on, the voltage across the capacitor C2 is maintained substantially constant. Thereby, the fluctuation
- the DC power supply circuit 2001 includes a rectifier circuit from the output terminal on the high potential side of the rectifier circuit 2 through the first current path while the switching element Q1 is on and the switching element Q2 is off.
- Current flows through the output terminal on the low potential side of 2 and the rectifier circuit through the second current path from the output terminal on the high potential side of the rectifier circuit 2 during the period when the switching element Q1 is turned off and the switching element Q2 is turned on.
- a current flows through the output terminal on the low potential side.
- the switching elements Q1 and Q2 operate so that the A period (first period) and the C period (second period) alternately come multiple times in each half cycle of the alternating current.
- the current continues to flow from the rectifier circuit 2 to the voltage conversion circuit 2003 in almost the entire period of the cycle, and the power factor viewed from the AC power supply AC side is increased.
- a general DC power supply circuit for improving the power factor there is a configuration in which a PFC circuit (power factor improving circuit) is connected to the rectifier circuit and a step-up / down circuit is further connected to the subsequent stage.
- the PFC circuit includes a switching element, an inductor, a control IC, and the like.
- the power factor can be improved without providing a separate PFC circuit, and accordingly, a circuit by reducing the circuit scale and reducing power loss in the PFC circuit. There is an advantage that efficiency can be improved. Since the DC power supply circuit 2001 is composed of general-purpose components such as the diode D2 and the diode bridge DB, there is an advantage that the cost can be reduced.
- the load 11 is a constant voltage load such as an LED
- the vicinity of the peak of the resonance voltage is automatically cut by the constant voltage VF of the load 11 so that the resonance does not become too large. Thereby, an unnecessary overvoltage protection circuit can be made unnecessary.
- the driving circuit U1 operates in the switching element Q1 in a mode (so-called discontinuous mode) in which the voltage conversion circuit 3 has a period in which no current flows through the inductors L2 and L3.
- the present invention is not limited to this, and the inductors L2 and L3 may be operated in a so-called critical mode or continuous mode in which a current always flows. In this case, it is only necessary to change the operation mode of the drive circuit U1 with the same configuration as the DC power supply circuit 1 described in the embodiment.
- FIG. 14 (a-1) shows a time waveform of the current IL2 flowing through the inductor L2 when the DC power supply circuit according to this modification is operating in the critical mode.
- the voltage generated at the other end of the inductor L2 The time waveform is shown in FIG.
- FIG. 14B-1 shows a time waveform of the current IL2 flowing through the inductor L2 when operating in the continuous mode
- FIG. 14B shows a time waveform of the voltage generated at the other end of the inductor L2 in this case. -2).
- both the critical mode and the continuous mode are generated at the other end of the inductor L2.
- the voltage can be maintained at the voltage Vth.
- the time waveform of the input voltage from the AC power supply AC to the rectifier circuit 2 is shown in FIG. 15A, and the time waveform of the voltage VC2 across the capacitor C2 is shown in FIG.
- the time waveform of the current Iin flowing from the AC power supply AC to the rectifier circuit 2 is shown in FIG. 15C, and the time waveform of the voltage VC2 across the capacitor C2 is shown in FIG.
- a voltage VLref (broken line) in FIG. 15C shows a time waveform when the drive circuit U1 operates in the discontinuous mode (see the first embodiment).
- the voltage VL at the other end of the inductor L2 is fixed at the voltage threshold Vth.
- step-down chopper circuit is provided as the voltage conversion circuit 3 as the first embodiment
- present invention is not limited to this, and a step-up / step-down chopper circuit may be provided.
- FIG. 16 shows a circuit diagram of a DC power supply circuit 201 according to this modification.
- symbol is attached
- the voltage conversion circuit 203 constitutes a step-up / step-down chopper circuit, and the connection relationship between the two inductors L22 and L23 and the diode D21 is different from that of the embodiment.
- the capacitor C22 has one end connected to the output terminal on the low potential side of the rectifier circuit 2.
- the inductors L22 and L23 are connected in series between the drain of the switching element Q1 and the other end of the capacitor C22.
- one end of the inductor L22 is connected to the drain of the switching element Q1.
- the inductor L23 has one end connected to the other end of the inductor L22 and the other end connected to the other end of the capacitor C22 and one end of the load 11.
- the diode D21 has an anode connected to a connection point between one end of the inductor L22 and the drain of the switching element Q1, and a cathode connected to the other end of the load 11.
- the diode D2 has an anode connected to the output terminal on the high potential side of the rectifier circuit 2 and a cathode connected to the other end of the inductor L22.
- the capacitor C24 is made of an electrolytic capacitor and is connected in parallel with the load 11.
- FIGS. 17A and 17B show a circuit diagram of the DC power supply circuit 201 according to the present embodiment and a current flow in the DC power supply circuit 201.
- FIG. 17 (a) shows the current flow when the switching element Q1 is on
- FIG. 17 (b) shows the current flow when the switching element Q1 is off.
- the switching element Q1 when the switching element Q1 is on, the potential at the other end of the inductor L22 is lower than the potential on the high potential side of the rectifier circuit 2 by the turn-on voltage of the diode D2. .
- the current flowing out from the high potential side of the rectifier circuit 2 passes through the other end of the inductor L22, the switching element Q1, and the resistor R2 in this order (hereinafter referred to as “the output terminal on the low potential side of the rectifier circuit 2”). This is referred to as “first current path”.
- the current flowing out from the other end of the capacitor C22 passes through the inductor L23, the inductor L22, the switching element Q1, and the resistor R2 in this order, and reaches a current path (hereinafter referred to as “third current path”).
- the capacitor C22 is discharged, and magnetic energy is accumulated in the inductors L22 and L23. At this time, power is not supplied to the load 11 side.
- the switching element Q1 when the switching element Q1 is in the OFF state, the current flowing out from the output terminal on the high potential side of the rectifier circuit 2 is in the order of the inductor L22, the diode D21, the load 11, and the capacitor C22.
- a path (hereinafter referred to as a “second current path”) that reaches the output terminal on the low potential side of the rectifier circuit 2 is followed.
- the current flowing out from one end of the inductor L22 follows a path (hereinafter referred to as “fourth current path”) to the other end of the inductor L23 via the diode D21 and the load 11 in this order.
- the current that follows the second current path does not flow when the charging of the capacitor C22 is completed. Further, the magnetic energy accumulated in the inductors L22 and L23 is discharged to the capacitor C22 side and also to the load 11 side when a current flows through the fourth current path.
- the voltage generated at the end is set to be equal.
- the on-duty of the switching element Q1 in the drive circuit U1 is set based on the voltage across the load 11, the number of windings of the inductors L22 and L23, and the winding ratio.
- the voltage generated at the other end of the inductor L22 is set to be lower than the voltage threshold value lower than the output voltage of the rectifier circuit 2 by the turn-on voltage Von of the diode D2.
- the voltage conversion circuit 3 includes the two inductors L2 and L3 has been described.
- the present invention is not limited to this.
- the inductor L3 is replaced with a diode. It may be.
- FIG. 18 shows a circuit diagram of a DC power supply circuit 501 according to this modification.
- symbol is attached
- the voltage conversion circuit 503 constitutes a step-up / step-down chopper circuit
- the first embodiment is that the cathode of the diode D2 is connected between the inductor L2 and the cathode of the diode D503. Is different.
- the inductor L2 has one end connected to the drain of the switching element Q1, and the other end connected to the cathode of the diode D503.
- the diode D503 has a cathode connected to the other end of the inductor L2 and an anode connected to the load 11.
- the diode D2 has an anode connected to the output terminal on the high potential side of the rectifier circuit 2, and a cathode connected to a connection point between the inductor L2 and the cathode of the diode D503.
- This diode D2 is for preventing current from flowing backward from the connection point between the inductor L2 and the cathode of the diode D503 to the capacitor C1.
- Capacitor C4 has one end connected to the cathode of diode D1 and the other end connected to the anode of diode D503.
- the voltage conversion circuit 3 outputs a voltage across the capacitor C4 to the load 11 connected in parallel with the capacitor C4.
- the capacitor C2 is composed of, for example, an electrolytic capacitor, a high dielectric constant ceramic capacitor, a film capacitor, or the like.
- FIGS. 19A and 19B show a circuit diagram of the DC power supply circuit 501 according to the present embodiment and a current flow in the DC power supply circuit 501.
- FIG. 19A shows the flow of current when the switching element Q1 is on
- FIG. 19B shows the flow of current when the switching element Q1 is off.
- first current path the potential at the connection point between the inductor L2 and the cathode of the diode D503 is higher than the potential on the high potential side of the rectifier circuit 2. It is lower by the turn-on voltage. As a result, the current that flows out from the high potential side of the rectifier circuit 2 passes through the inductor L2, the switching element Q1, and the resistor R2 to the output terminal on the low potential side of the rectifier circuit 2 (hereinafter referred to as “first current path”). ").
- the current flowing out from the other end of the capacitor C2 passes through the load 11, the diode D503, the inductor L2, the switching element Q1, and the resistor R2 in this order (hereinafter referred to as “third current path”).
- third current path the capacitor C2 is discharged, magnetic energy is accumulated in the inductor L2, and power is supplied to the load 11 side.
- the switching element Q1 when the switching element Q1 is in the OFF state, the current flowing out from the output terminal on the high potential side of the rectifier circuit 2 passes through the inductor L2, the diode D1, and the capacitor C2 in this order.
- the path to the output terminal on the low potential side of the rectifier circuit 2 (hereinafter referred to as “second current path”) is followed.
- the current flowing out from one end of the inductor L2 follows a path (hereinafter referred to as “fourth current path”) that reaches the other end of the inductor L2 through the diode D1, the load 11, and the diode D503 in this order.
- the current flowing through the second current path does not flow when the charging of the capacitor C2 is completed.
- the magnetic energy accumulated in the inductor L2 is released to the load 11 side when a current flows through the fourth current path.
- FIG. 20 shows a circuit diagram of a DC power supply circuit 301 according to this modification.
- symbol is attached
- the voltage conversion circuit 203 constitutes a flyback converter, and includes a switching element Q1, an inductor L32, a transformer TF33 having a primary winding L331 and a secondary winding L332, and a diode D2. , D31, capacitors C32 and C34, and a resistor R2.
- the polarity of the primary winding L331 and the polarity of the secondary winding L332 are opposite.
- the switching element Q1 has a source connected to the output terminal on the low potential side of the rectifier circuit 2 via the resistor R2, a gate connected to the drive circuit U1 via the resistor R11, and a drain connected to one end of the inductor L32. Has been.
- the other end of the inductor L32 is connected to one end of the primary winding L331 of the transformer TF33.
- the other end of the primary winding L331 of the transformer TF33 is connected to the capacitor C32.
- One end of the secondary winding L332 of the transformer TF33 is connected to one end of the load 11 via the diode D31, and the other end of the secondary winding L332 is connected to the other end of the load 11.
- the capacitor C34 is connected in parallel with the load 11.
- the voltage conversion circuit 3 outputs a voltage across the capacitor C34 to the load 11 connected in parallel with the capacitor C34.
- the inductors L2 and L3 described in the first embodiment do not need to be separate bodies, and the cathode of the diode D2 may be electrically connected in the middle of one winding.
- a circuit diagram of a DC power supply circuit 401 according to this modification is shown in FIG.
- the voltage conversion circuit 403 includes an inductor L402 with an intermediate tap, and the cathode of the diode D2 is connected to the intermediate tap of the inductor L402.
- the magnitude of the current flowing from the capacitor C1 to the inductor L402 via the intermediate tap can be calibrated by changing the position of the intermediate tap in the inductor L402.
- the inductor can be reduced in size, the entire DC power supply circuit can be reduced in size.
- FIG. 22 shows a circuit diagram of a DC power supply circuit 2201 according to this modification.
- symbol is attached
- the voltage conversion circuit 203 includes a diode D201 having an anode connected to the other end of the capacitor C3 and a cathode connected to the inductor L2 via the load 11.
- the circuit configuration can be simplified and the circuit scale can be reduced as compared with the DC power supply circuit 1 according to the embodiment.
- FIG. 23 shows a circuit diagram of a DC power supply circuit 2301 according to another modification.
- symbol is attached
- the voltage conversion circuit 2303 includes a diode D311 having an anode connected to the other end of the capacitor C3, a cathode connected to the inductor L2 via the load 11, and an anode connected to the inductor L2 via the load 21. And a diode D312 having a cathode connected to the other end of the capacitor C3.
- each of the loads 11 and 12 constitutes a light emitting module formed by connecting a plurality of light emitting diodes in series.
- the load 11 conducts only a current flowing in a direction from one end connected to the cathode of the diode D311 to the other end, and the load 21 a current flowing in a direction from one end connected to the cathode of the diode D312 to the other end. Only conduct.
- the current phase flowing through the load 11 and the current phase flowing through the load 12 are shifted by exactly a half cycle of alternating current.
- the light-emitting modules that make up the flashes alternately repeat. Therefore, if the light emitting modules constituting each of the loads 11 and 21 are made one light emitting unit, the light output fluctuations of the light emitting modules constituting the load 11 are compensated by the light outputs of the light emitting modules constituting the load 21. Then, there is an advantage that the fluctuation of the light output of the light emitting unit can be made inconspicuous at a distance from the light emitting unit.
- the voltage conversion circuit 2003 operates in a so-called separately-excited system including the drive circuit U2001 configured by one integrated circuit and the constant voltage circuit 4 that supplies power to the drive circuit U2001.
- the direct current power supply circuit 2001 that has been described has been described, the present invention is not limited to this, and may operate in a so-called self-excited system.
- FIG. 24 shows a circuit diagram of a DC power supply circuit 2401 according to this modification.
- symbol is attached
- the voltage conversion circuit 2403 includes switching elements Q401 and Q402, an inductor L402, capacitors C5, C402, C403, C404, and C468, diodes D460a and D461a, and resistors R467a and R467b.
- the voltage conversion circuit 403 includes a transformer Tr464, diodes D453, D466a, D466b, a capacitor C455, resistors R452, R465a, R465b, and a triac T454.
- the transformer Tr464 includes a primary winding L464a having one end connected to the inductor L402, a secondary winding L464b having one end connected to the other end of the primary winding L464a, and an output end on the low potential side of the rectifier circuit 2. And a tertiary winding L464c connected to.
- the capacitor C402 has one end connected to the output terminal on the low potential side of the rectifier circuit 2.
- the capacitor C403 has one end connected to the other end of the capacitor C402 and the other end connected to the diode bridge DB.
- the inductor L402 has one end connected to the other input end of the diode bridge DB and the other end connected to the primary winding L464a of the transformer Tr464.
- Switching element Q401 is made of an N-channel MOSFET, and has a source connected to the output terminal on the low potential side of rectifier circuit 2 via resistor R467b and a gate connected to the other end of tertiary winding L464c of transformer Tr464. The drain is connected to the other end of the primary winding L464a.
- Switching element Q402 is made of an N-channel MOSFET, and has a source connected to the other end of primary winding L464a via resistor R467b and a gate connected to the other end of secondary winding L464b via resistor R465a. In addition, the drain is connected to the other end of the capacitor C2.
- the diode D460a has an anode connected to the output terminal on the low potential side of the rectifier circuit 2, and a cathode connected to the other end of the primary winding L464a.
- the diode D461a has an anode connected to the other end of the primary winding L464a and a cathode connected to the other end of the capacitor C402.
- the capacitor C468 has one end connected to the other end of the primary winding L464a and the other end connected to the other end of the capacitor C402.
- the anode of the diode D453 is connected to the output terminal on the high potential side of the rectifier circuit 2 via the resistor R452, and the cathode is connected to the other end of the primary winding L464a.
- the capacitor C455 has one end connected to the output terminal on the low potential side of the rectifier circuit 2 and the other end connected to the anode of the diode D453.
- Triac T454 is interposed between the other end of capacitor C455 and the gate of switching element Q401.
- Diode D466a has an anode connected to the other end of primary winding L464a and a cathode connected to the gate of switching element Q402.
- the diode D466b has an anode connected to the gate of the switching element Q401 and a cathode connected to the output terminal on the low potential side of the rectifier circuit 2.
- the capacitor C404 has one end connected to the other end of the capacitor C403 and the other end connected to one end of the inductor L402.
- the capacitor C404 is for smoothing the input voltage to the diode bridge DB.
- the constant voltage circuit 4 or the like is not necessary, and thus the circuit configuration can be simplified.
- the capacitors C43 and C47 are charged at the timing when the inductor L2 releases magnetic energy during the period when the switching element Q1 is turned off and the switching element Q2 is turned on.
- the example has been described in which the capacitor C47 is discharged while the switching element Q2 is turned off and the charge accumulated in the capacitor C47 is sent to the capacitor C43.
- a transformer may be provided instead of the inductor L2, and a current may be passed from the secondary winding of the transformer to the constant voltage circuit (the constant voltage circuit is charged).
- FIG. 25 shows a circuit diagram of a DC power supply circuit 2501 according to this modification.
- symbol is attached
- the voltage conversion circuit 2503 includes a transformer Tr502 having a primary winding L511 and a secondary winding L512.
- the polarity of the primary winding L511 and the polarity of the secondary winding L512 are the same.
- a capacitor C547 is connected between the connection point between the secondary winding L512 of the transformer Tr502 and the resistor R46 and the output terminal on the low potential side of the rectifier circuit 2.
- the capacitor C547 functions as a so-called snubber capacitor for the secondary winding L512.
- the current is supplied from the secondary winding L512 to the constant voltage circuit 504 at the timing when the primary winding L511 releases magnetic energy. Is supplied. Specifically, a current flows from the secondary winding L512 to the capacitor C43 via the resistor R46 and the diode D45, and the capacitor C43 is charged. A configuration without the capacitor C547 may be used.
- the example in which the polarity of the primary winding L511 of the transformer Tr502 and the polarity of the secondary winding L512 are the same has been described.
- the polarity of the secondary winding L512 may be opposite.
- current is supplied from the secondary winding L512 to the constant voltage circuit 504 at a timing when magnetic energy is accumulated in the primary winding L511 during the period when the switching element Q1 is on and the switching element is off. Is done.
- the present invention is not limited to this, and the timing at which the primary winding L511 emits magnetic energy and the magnetic energy to the primary winding L511 are described.
- the current may be supplied from the secondary winding L512 to the constant voltage circuit 504 at both of the timing when the voltage is accumulated.
- FIG. 26 shows a circuit diagram of a DC power supply circuit 2601 according to another modification. Note that. The same components as those illustrated in FIG. 25 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.
- the DC power supply circuit 2601 is different from the configuration shown in FIG. 12 in that the voltage conversion circuit 2603 includes a diode bridge DB2 whose input ends are connected between both ends of the secondary winding L512 of the transformer Tr502.
- the output terminal on the high potential side of the diode bridge DB2 is connected to the constant voltage circuit 504, and the output terminal on the low potential side is connected to the output terminal on the low potential side of the rectifier circuit 2.
- the polarity of the primary winding L511 and the polarity of the secondary winding L512 may be opposite.
- the current is supplied from the diode bridge DB2 to the constant voltage circuit 504 at any timing when the primary winding L511 releases magnetic energy or when magnetic energy is accumulated in the primary winding L511. .
- the constant voltage circuit 4 Electric power may be supplied.
- FIG. 27 shows a circuit diagram of a DC power supply circuit 2701 according to a modification.
- symbol is attached
- the switching element Q702 is interposed between the connection point of the inductor L2 and the switching element Q1 of the voltage conversion circuit 3 and the constant voltage circuit 2704. Further, the drive circuit U2002 includes a control terminal te4 that outputs a control signal voltage for controlling the switching element Q702.
- Switching element Q702 is composed of an N-channel MOSFET.
- the switching element Q702 has a source connected to the constant voltage circuit 704, a gate connected to the control terminal te4 of the drive circuit U2002 via a resistor R712, and a drain connected to the connection point of the switching elements Q1 and Q2. Yes.
- the resistor R46 is directly connected to the source of the switching element Q702. That is, the constant voltage circuit 504 in FIG. 25 is configured without the capacitor C547.
- the driving circuit U2002 sets the signal voltage of the output terminal te1 to a predetermined voltage higher than 0V and turns off the switching element Q1
- the voltage at the connection point of the inductor La and the switching element Q1 is a predetermined voltage.
- the switching element Q702 is turned on by setting the signal voltage at the control terminal te4 to a predetermined voltage higher than 0V.
- the timing for turning on the switching element Q702 is set in advance. Thereby, the power loss at the resistor R46 in the constant voltage circuit 704 can be reduced, and the circuit efficiency can be improved.
- the circuit can be reduced in size.
- the high frequency current accompanying the on / off operation of the switching element Q1 generated in the voltage conversion circuit 2003 flows from the voltage conversion circuit 2003 to the AC power supply AC via the rectifier circuit 2. To do. Then, high frequency noise and high frequency ripple leak to the outside.
- a noise filter 2005 including an inductor NF and capacitors C0 and C1 may be provided between the DC power supply circuit 2001 and the AC power supply AC.
- the DC power supply circuit 2801 may include a noise filter 2205 connected between the rectifier circuit 2 and the voltage conversion circuit 3.
- This noise filter 2205 has a configuration in which an inductor NF is inserted in series between a capacitor connected between the output terminals of the rectifier circuit 2 and the capacitor and the voltage conversion circuit 2003 (diode D2 (see FIG. 6)). . Also, it is better to change the place where the noise filter is inserted between the case where the purpose is to reduce the high frequency ripple and the case where the purpose is to reduce the high frequency noise.
- FIG. 26B it is preferable to connect the capacitor C1 to the voltage conversion circuit 2003 side with respect to the inductor NF.
- two capacitors may be connected to both sides of the inductor NF.
- another inductor NF may be provided on the low potential side of the rectifier circuit 2.
- the example of the DC power supply circuit 1 including the diode bridge DB as the current supply circuit has been described.
- the present invention is not limited to this.
- the current supply circuit may be configured by only a wiring connecting the other end of the capacitor C2 and one end of the load 11 and a wiring connecting the one end of the inductor and the other end of the load 11.
- the switching element Q1 constituting part of the voltage conversion circuit 3 or the switching elements Q1 and Q2 constituting part of the voltage conversion circuit 2003 are constituted by N-channel MOS transistors. Although an example has been described, the present invention is not limited to this, and a P-channel MOS transistor may be used. Further, the switching elements Q1, Q2 may be composed of bipolar transistors.
- the DC power supply circuit 1 and 2001 may be used by connecting a power regulator for adjusting the power input to the DC power supply circuit 1 between the DC power supply AC.
- This regulator generally uses a triac or the like. When the input voltage to the DC power supply circuit 1 side is zero, if the current is supplied to the DC power supply circuit 1 side, the triac will malfunction. There is a fear.
- the input voltage phase and the input current phase substantially coincide with each other, and the input current can flow even when the input voltage is low near the zero cross. Thereby, when using the power regulator using a triac etc., the malfunction of a power regulator can be prevented.
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Abstract
Description
<1>構成
本実施の形態に係る直流電源回路1の回路図を図1に示す。
整流回路2は、4つのダイオードからなるダイオードブリッジから構成されている。
電圧変換回路3は、昇圧回路を構成するものであり、スイッチング素子Q1と、インダクタ(インダクタ)L2と、インダクタ(補助インダクタ)L3と、ダイオードD1,D2と、コンデンサC2,C4と、抵抗R2とを備える。スイッチング素子Q1は、Nチャネル型MOSFETからなり、ソースが抵抗R2を介して整流回路2の低電位側の出力端に接続され且つゲートが抵抗R11を介して駆動回路U1に接続されるとともに、ドレインがインダクタL2に接続されている。ここで、抵抗R2は、両端間に生じる電圧に基づいてスイッチング素子Q1に流れるドレイン電流を検出するためのものである。インダクタL2は、一端がスイッチング素子Q1のドレインに接続され、他端がインダクタL3に接続されている。インダクタL3は、一端がインダクタL2の上記他端に接続され、他端がコンデンサC4に接続されている。ダイオードD2は、アノードが整流回路2の高電位側の出力端に接続され、カソードがインダクタL2の他端に接続されている。このダイオードD2は、インダクタL2,L3に電流が流れなくなりインダクタL2,L3の接続点の電位がコンデンサC1の高電位側の電位に比べて高くなった場合、インダクタL2の他端からコンデンサC1へ電流が逆流してしまうことを防止するためである。ダイオードD1は、インダクタL2およびスイッチング素子Q1の間からコンデンサC2に充電電流を供給する充電電流供給路に介挿されている。そして、ダイオードD1は、アノードがインダクタL2の上記一端およびスイッチング素子Q1のドレインに共通接続され、カソードがコンデンサC2に接続されている。コンデンサC2は、一端が整流回路2の低電位側の出力端に接続され、他端がダイオードD1のカソードに接続されている。コンデンサC4は、一端がダイオードD1のカソードに接続され、他端がインダクタL3の上記他端に接続されている。ここで、コンデンサC2の他端から負荷11、インダクタL3、インダクタL2、スイッチング素子Q1および抵抗R1の順に経由してコンデンサC2の一端に至る電流経路が、コンデンサC2の放電電流経路を構成している。
駆動回路U1は、スイッチング素子Q1をPWM(Pulse Width Modulation)制御により駆動させるための矩形波状の電圧波形を有する制御信号(以下、「PWM信号」と称す)を出力する。
定電圧回路4は、抵抗R41,R42と、コンデンサC43と、ツェナーダイオードZD44とを備える。ここで、抵抗R41,R42は、整流回路2の出力端間に直列に接続されている。そして、抵抗R41は、一端が整流回路2の高電位側の出力端に接続されており、抵抗R42は、抵抗R41の他端と整流回路2の低電位側の出力端との間に接続されている。コンデンサC43は、抵抗R42の両端間に接続されている。ツェナーダイオードZD44は、アノードが整流回路2の低電位側の出力端に接続され、カソードが抵抗R41,R42の接続点に接続されるとともに駆動回路U1の電源端子te0に接続されている。これにより、駆動回路U1の電源端子te0の電位は、ツェナーダイオードZD44のカソードに生じる一定の電位に維持される。
次に、本実施の形態に係る直流電源回路の動作について説明する。
結局、本実施の形態に係る直流電源回路1では、第1期間中、整流回路2の高電位側の出力端からインダクタL2およびスイッチング素子Q1を経由して整流回路2の低電位側の出力端に至る第1電流経路に電流が流れ、第2期間中、整流回路2の高電位側の出力端からインダクタL2、充電電流供給路およびコンデンサC2を経由して整流回路2の低電位側の出力端に至る第2電流経路に電流が流れる。そして、交流の各半周期において、第1期間と第2期間とが交互に複数回到来するので、交流の半周期における略全期間において整流回路2から電圧変換回路3に電流が流れ続けることとなり、交流電源側から見た力率が高くなる。
本実施の形態に係る直流電源回路2001の回路図を図6に示す。
(1)実施の形態1では、図3に示すように、駆動回路U1が、電圧変換回路3をインダクタL2,L3に電流が流れない期間が存在するモード(いわゆる不連続モード)でスイッチング素子Q1を動作させる例について説明したが、これに限定されるものではなく、インダクタL2,L3に常に電流が流れ続けるいわゆる臨界モードや連続モードで動作させるものであってもよい。この場合、実施の形態で説明した直流電源回路1と同様の構成で、駆動回路U1の動作モードを変更するたけでよい。
2 整流回路
3,203,2003,2203,2303,2403,2503,2603 電圧変換回路
4,504,704 定電圧回路
11,21 負荷
2005,2205 ノイズフィルタ
C0,C2,C3,C4,C5,C22,C24,C32,C34,C43,C47,C402,C403,C404,C455,C468,C547 コンデンサ
D1,D2,D3,D21,D31,D45,D48,D201,D311,D312,D453,D460a,D461a,D466a,D466b ダイオード
DB,DB2 ダイオードブリッジ
L2,L3,L22,L23,L32,L402 インダクタ
L331,L464a,L511 一次巻線
L332,L464b,L512 二次巻線
L464c 三次巻線
Q1,Q2,Q401,Q402,Q702 スイッチング素子
R1,R2,R11,R12,R41,R42,R46,R452,R465a,R467a,R467b,R712 抵抗
T454 トライアック
TF33,Tr464,Tr502 トランス
U1,U2001,U2002 駆動回路
ZD44 ツェナーダイオード
Claims (12)
- 交流電源から供給される交流を整流する整流回路と、
前記整流回路の出力端間に接続され且つ前記整流回路からの入力電圧を変換して出力端に接続された負荷に供給する電圧変換回路とを備え、
前記電圧変換回路は、一端が前記整流回路の低電位側の出力端に接続されたコンデンサと、前記コンデンサの他端から前記コンデンサの一端に至る、前記コンデンサからの放電電流経路の途中に介挿されたインダクタおよびスイッチング素子からなる直列回路と、前記インダクタにおける前記スイッチング素子に接続される一端と前記コンデンサの他端とを接続し且つ前記インダクタから前記コンデンサの他端に向かって電流を供給する充電電流供給路とを有し、
前記整流回路の高電位側の出力端は、前記インダクタの他端に接続され、
前記電圧変換回路は、
交流の各半周期において、前記スイッチング素子をオンオフさせることにより、前記整流回路の高電位側の出力端から前記インダクタおよび前記スイッチング素子を経由して前記整流回路の低電位側の出力端に至る第1電流経路に電流が流れる第1期間と、前記整流回路の高電位側の出力端から前記インダクタ、前記充電電流供給路および前記コンデンサを経由して前記整流回路の低電位側の出力端に至る第2電流経路に電流が流れる第2期間とを複数回交互に到来させる
ことを特徴とする直流電源回路。 - 前記電圧変換回路は、更に、
前記放電電流経路における前記コンデンサの前記他端と前記直列回路との間に、前記インダクタと直列に接続された状態で介挿された補助インダクタを有し、
前記整流回路の高電位側の出力端と前記インダクタとの接続は、前記インダクタと前記補助インダクタとの間の接続点を経由してなされており、
前記第1電流経路および前記第2電流経路は、前記整流回路の高電位側の出力端から前記接続点を経由して前記インダクタに至り、
前記第1期間では、前記第1電流経路に電流が流れると同時に、前記コンデンサの電荷が前記放電電流経路を経て放電することにより前記インダクタおよび前記補助インダクタにエネルギが蓄積され、
前記第2期間では、前記第2電流経路に電流が流れると同時に、前記インダクタおよび前記補助インダクタに蓄積されたエネルギが前記充電電流供給路を経て前記コンデンサ側に放出されることにより前記コンデンサが充電される
ことを特徴とする請求項1記載の直流電源回路。 - 前記補助インダクタは、一端が前記コンデンサの他端に前記負荷を介して接続され、
前記充電電流供給路は、アノードが前記インダクタの一端に接続され且つカソードが前記コンデンサの他端に接続されたダイオードを含む
ことを特徴とする請求項2記載の直流電源回路。 - 前記放電電流経路は、一端が前記コンデンサの他端および前記負荷の一端に接続された前記補助インダクタと、一端が前記スイッチング素子に接続され且つ他端が前記補助インダクタの他端に接続された前記インダクタと、前記スイッチング素子とを含み、
前記充電電流供給路は、アノードが前記インダクタの一端に接続され且つカソードが前記負荷の一端に接続されたダイオードを含む
ことを特徴とする請求項2記載の直流電源回路。 - 前記インダクタは、中間タップが設けられ且つ前記整流回路の高電位側の出力端と前記インダクタとの接続は、前記中間タップを経由してなされており、
前記第1電流経路および前記第2電流経路は、前記整流回路の高電位側の出力端から前記中間タップを経由して前記インダクタに至り、
前記第1期間では、前記第1電流経路に電流が流れると同時に、前記コンデンサの電荷が前記放電電流経路を経て放電することにより前記インダクタにエネルギが蓄積され、
前記第2期間では、前記第2電流経路に電流が流れると同時に、前記インダクタに蓄積されたエネルギが前記充電電流供給路を経て前記コンデンサ側に放出されることにより前記コンデンサが充電され、
前記インダクタにおける、前記中間タップの位置を変更することにより前記第1電流経路および前記第2電流経路に流れる電流の大きさを校正できる
ことを特徴とする請求項1記載の直流電源回路。 - 前記充電電流供給路は、前記インダクタの一端と前記コンデンサの他端との間に接続された副スイッチング素子を含み、
前記放電電流経路は、一端が前記コンデンサの他端に接続された共振用コンデンサと、前記インダクタの他端と前記共振用コンデンサの他端との間に接続され前記負荷に電流を供給する電流供給回路とを含み、
前記整流回路の高電位側の出力端は、前記インダクタの他端と前記電流供給回路との間の接続点に接続され、
前記副スイッチング素子は、前記第1期間においてオフし、前記第2期間においてオフするように動作し、
前記第2電流経路は、前記インダクタから前記副スイッチング素子を経由して前記コンデンサの他端に至り、
前記第1期間では、前記整流回路の高電位側から、前記第1電流経路を電流が流れることにより前記インダクタに磁気的エネルギが蓄積されると同時に、前記コンデンサが、自己に蓄積された電荷を、前記共振用コンデンサおよび前記電流供給回路を通じて前記負荷に放電し、
前記第2期間では、前記インダクタに蓄積された磁気的エネルギが前記副スイッチング素子、前記共振用コンデンサおよび前記電流供給回路を通じて前記負荷に放出されると同時に、前記整流回路の高電位側の出力端から、前記第2電流経路を電流が流れることにより前記コンデンサが充電される
ことを特徴とする請求項1記載の直流電源回路。 - 前記電流供給回路は、ダイオードブリッジから構成され、2つの入力端の一方が前記共振用コンデンサの他端に接続され且つ他方が前記インダクタの他端に接続されるとともに、2つの出力端間に前記負荷が接続され、
前記放電電流経路は、前記コンデンサの他端から、前記共振用コンデンサ、前記電流供給回路の一方の入力端、前記負荷、前記電流供給回路の他方の入力端、前記スイッチング素子の順に経由して前記コンデンサの一端に至り、
前記エネルギ放出路は、前記インダクタの一端から、前記副スイッチング素子、前記共振用コンデンサ、前記電流供給回路の一方の入力端、前記負荷、前記電流供給回路の他方の入力端の順に経由して前記インダクタの他端に至る
ことを特徴とする請求項6記載の直流電源回路。 - 前記電流供給回路は、アノードが前記共振用コンデンサの他端に接続され且つカソードが前記負荷を介して前記インダクタの他端に接続されたダイオードから構成される
ことを特徴とする請求項6記載の直流電源回路。 - 前記負荷は、第1負荷および第2負荷から構成され、
前記電流供給回路は、
アノードが前記共振用コンデンサの他端に接続され且つカソードが前記第1負荷を介して前記インダクタの他端に接続された第1ダイオードと、
アノードが前記第2負荷を介して前記インダクタの他端に接続され且つカソードが前記共振用コンデンサの他端に接続された第2ダイオードとから構成される
ことを特徴とする請求項6記載の直流電源回路。 - 前記電圧変換回路は、更に、
前記スイッチング素子に並列に接続された第1の一方向性素子と、
前記副スイッチング素子に並列に接続された第2の一方向性素子とを有する
ことを特徴とする請求項6乃至9のいずれか1項に記載の直流電源回路。 - 前記スイッチング素子および前記副スイッチング素子は、FETから構成され、
前記第1の一方向性素子は、アノードが前記スイッチング素子のソースに接続され且つカソードが前記スイッチング素子のドレインに接続されたダイオードからなり、
前記第2の一方向性素子は、アノードが前記副スイッチング素子のソースに接続され且つカソードが前記副スイッチング素子のドレインに接続されたダイオードからなる
ことを特徴とする請求項10記載の直流電源回路。 - 前記第1期間から、前記第2期間に移行する際、および、前記第2期間から、前記第2期間に移行する際に、前記スイッチング素子および前記副スイッチング素子のいずれもがオフ状態で維持される期間が存在する
ことを特徴とする請求項10または請求項11記載の直流電源回路。
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US14/376,984 US9257901B2 (en) | 2012-02-09 | 2012-10-18 | DC power supply circuit |
JP2013505257A JP5250163B1 (ja) | 2012-02-21 | 2012-10-18 | 直流電源回路 |
EP12869175.5A EP2819292B1 (en) | 2012-02-21 | 2012-10-18 | Dc power supply circuit |
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CN105207472A (zh) * | 2015-10-27 | 2015-12-30 | 杰华特微电子(杭州)有限公司 | 提升buck输出电压的电路 |
US10312804B2 (en) * | 2016-02-05 | 2019-06-04 | Shunzou Ohshima | Power supply apparatus with power factor correction using fixed on and off periods |
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JP6340463B1 (ja) * | 2017-09-26 | 2018-06-06 | 高周波熱錬株式会社 | 電源装置 |
US11863062B2 (en) * | 2018-04-27 | 2024-01-02 | Raytheon Company | Capacitor discharge circuit |
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US9257901B2 (en) | 2016-02-09 |
JP5250163B1 (ja) | 2013-07-31 |
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EP2819292B1 (en) | 2017-12-06 |
US20150009728A1 (en) | 2015-01-08 |
JPWO2013124921A1 (ja) | 2015-05-21 |
EP2819292A4 (en) | 2015-04-01 |
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