JP2008245487A - Power factor improved converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power factor improved converter that stably drives a thyristor/triac used for inrush prevention, while supplying stable power, having less pulsating flow for auxiliary power. <P>SOLUTION: In the power factor improving converter 100, power at a constant voltage is supplied as auxiliary power. Power at a constant voltage is generated by rectifying and totaling both of power at a positive voltage V<SB>W2B</SB>induced in a secondary winding W2, when turned on by on/off control of a switching element Q1 and power at a negative voltage V<SB>W2A</SB>induced in the secondary winding W2, when turned off by on/off control. A trigger voltage having a bridge-like pulse waveform is induced in a winding W3 for driving elements, and it becomes possible to apply an adequate voltage to the gate of a thyristor TH at the time of 0-degree phase angle or of 180-degree phase angle of input current. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power factor correction converter, and more particularly to a power factor correction converter connected to a front stage of a switching power supply for power factor improvement.

  In recent years, a switching power supply having excellent conversion efficiency has been widely used as a power supply unit of electronic equipment.

  However, since the switching power supply is a capacitor input type rectification method, a considerable amount of harmonic components are included in the input current. As the use of such devices increases, various harmonic disturbances occur, such as the power line waveform being distorted, causing other electronic devices to malfunction, and the capacity of power facilities being insufficient.

Therefore, an active filter for improving the power factor is provided in the front stage of the switching power supply.
JP 2001-119934 A (FIG. 1)

  FIG. 4 is an explanatory diagram showing a configuration of a conventional power factor correction converter 200 that rectifies AC power supplied from the outside such as a commercial power source into DC power and supplies the DC power to an electronic device. In FIG. 4, the control circuit IC1 controls the switching operation of the switching element Q1 so that the input waveform Vdet from the AC power supply AC and the current waveform Idet flowing through the diode bridge DB are similar to each other, and is input from the AC power supply AC. The current waveform is a sine wave. By the operation of the control circuit IC1, the power factor becomes approximately 1, and the harmonic current is suppressed.

  AC power supplied from an AC power source AC such as a commercial power source is rectified by a diode bridge DB composed of a plurality of diodes. The rectified output of the diode bridge DB is input to one end of the switching element Q1 via a parallel circuit of a resistor R1 and a thyristor TH and a choke coil L1 provided to prevent the occurrence of an inrush current when the AC power supply AC is turned on. ing.

  The choke coil L1 drives the auxiliary winding W2 (hereinafter referred to as the winding W2) for outputting the auxiliary power supply Vcc and the gate of the thyristor TH to the common core with the main winding W1 (hereinafter referred to as the winding W1). Gate driving windings W3 (hereinafter referred to as windings W3) are wound in directions to output a positive voltage when the switching element Q1 is turned on.

  The electric power induced in the winding W2 of the choke coil L1 is on / off controlled by a switching element Q1 driven by a PWM control signal output from the control circuit IC1, and is converted into a direct current by a rectifier circuit including a diode D1 and a capacitor CA. Rectified. The electric power rectified to direct current by this rectifier circuit is adjusted to a constant voltage Vcc via a series regulator SR, and is supplemented to an external circuit in the electronic device to which the power factor correction converter 200 is connected, a control power source of the power factor correction converter, and the like. Power is supplied.

  Further, the control circuit IC1 controls the switching operation of the switching element Q1 so that the output voltage VH becomes a desired boosted DC voltage, and the output voltage VH is maintained at a constant DC voltage. This output voltage VH is input to a DC / DC converter connected in the subsequent stage, is controlled to a predetermined DC voltage, and is supplied to the load as electric power.

  A winding W3 wound around a core coaxial with the winding W1 of the choke coil L1 induces a voltage that is on / off controlled by the switching element Q1. Here, a parallel circuit of a resistor R1 and a thyristor TH is connected between the diode bridge DB and the choke coil L1, and flows from the diode bridge DB to the capacitor Co until the control circuit IC1 is activated through the resistor R5. Limit inrush current. When the control circuit IC1 is activated and the switching element Q1 starts a switching operation, the voltage induced in the winding W3 is applied to the gate of the thyristor TH, the resistor R1 is short-circuited, and the diode bridge is activated during the operation of the power factor correction converter 200. Power is transmitted from the DB to the choke coil L1.

  However, such a power factor improving converter 200 in the prior art has the following problems. FIG. 5 is a waveform diagram of the induced voltage in the winding W2. As shown in FIG. 5, the induced voltage envelope has a sinusoidal switching waveform based on the turn ratio of the winding W1 and the winding W2. For this reason, since the voltage greatly decreases in the valley portion of the switching waveform, the turn ratio between the winding W1 and the winding W2 is such that high voltage power is induced in advance in order to output auxiliary power having a constant voltage. Therefore, it is necessary to prepare a choke coil L1 set with Along with the preparation of the choke coil L1, there is a problem that the capacity of the capacitor CA must be increased and the loss of the series regulator SR is increased.

  FIG. 6 is a waveform diagram of a voltage induced from the element driving winding W3 and applied to the gate of the thyristor TH. As shown in FIG. 6, the voltage applied to the gate of the thyristor TH is also a sinusoidal switching waveform based on the turn ratio between the winding W1 and the winding W3. For this reason, the voltage drops greatly at the phase of the valley portion of the switching waveform, that is, when the thyristor TH starts to be turned on, so that a sufficient voltage cannot be applied to the gate. Therefore, in order to reliably turn on the thyristor TH during the operation of the power factor correction converter 200, it is necessary to set the turns ratio of the windings W1 and W3 so that a high voltage is induced in advance. There is a problem that the loss of the gate resistors R2 and R3 connected to the thyristor TH is increased.

  Therefore, the present invention is capable of supplying stable power with less pulsating current from the secondary winding of the choke coil and capable of stably operating a transmission circuit that transmits DC power after rectification. It is an object to provide a rate improving converter.

  In order to achieve the above-described problems, a power factor correction converter according to the present invention is rectified by a first rectifier circuit that rectifies AC power supplied from the outside into DC power, and the first rectifier circuit. A transmission circuit that transmits DC power, a rush preventing element that prevents conduction of power to the transmission circuit by making the transmission circuit conductive when a voltage is applied to a predetermined gate, and the transmission circuit. A switching element that controls on / off of DC power to be applied to the main winding of the choke coil, and a gate of the inrush prevention element that is magnetically coupled to the choke coil and wound in a direction opposite to the main winding And an element driving winding connected to the element.

  With such a configuration, the main winding of the choke coil and the element driving winding have opposite polarities, and a positive voltage is generated in the element driving winding when the main winding is turned off. For this reason, when the thyristor, triac, or the like, which is an inrush prevention element, is turned on, the positive voltage at the time of switching of the main winding becomes the highest, so that a sufficient voltage can be applied to the gate of the inrush prevention element. . Thus, it is not necessary to set the turn ratio between the main winding and the element driving winding so as to induce a high voltage from the time when the main winding is turned on, and the loss can be reduced accordingly. In addition, it is possible to reduce circuit loss such as gate resistance around the transmission circuit.

  In addition, another power factor improving converter according to the present invention transmits a first rectifier circuit that rectifies AC power supplied from outside into DC power, and DC power rectified by the first rectifier circuit. A transmission circuit, an inrush prevention element for making the transmission circuit conductive when a voltage is applied to a predetermined gate to prevent inrush of power into the transmission circuit, and on / off of DC power transmitted by the transmission circuit A switching element that is controlled and applied to the main winding of the choke coil, and is magnetically coupled to the choke coil separately from the main winding, and when the switching element is turned off, the gate of the inrush prevention element An element driving winding for applying a positive voltage may be provided.

  With such a configuration, the waveform of the voltage induced in the element driving winding by applying DC power to the main winding of the choke coil is a bridge-like pulse that is a negative voltage when the switching element is turned off. It becomes a waveform. Therefore, even when the triac is driven with a negative gate voltage to prevent inrush, a sufficient voltage can be applied to the gate from the start of turning on the thyristor, etc., and the turns ratio is set so as to induce a high voltage from the beginning. There is no need to set, and the loss can be reduced accordingly. In addition, it is possible to reduce circuit loss such as gate resistance around the transmission circuit.

  In another power factor improving converter according to the present invention, a first rectifier circuit that rectifies AC power supplied from the outside into DC power, and DC power rectified by the first rectifier circuit is turned on / off. A switching element to be controlled and applied to the first (primary) winding of the choke coil, and a positive voltage induced by the second (secondary) winding of the choke coil when controlled by the switching element. A second rectifier circuit that rectifies and outputs power to DC power, and a negative voltage power induced by the second (secondary) winding of the choke coil when the switching element is turned off. And a third rectifier circuit for rectifying and outputting the output.

  With such a configuration, the power of both positive and negative voltages induced when ON / OFF control is performed by the switching element using the second rectifier circuit and the third rectifier circuit is rectified and output to DC power. And a constant voltage with no pulsating current. For this reason, it is not necessary to set the turns ratio so as to induce a high voltage, and stable power can be supplied to an external circuit or the like provided in an electronic device or the like. Loss can be reduced.

  Furthermore, in the power factor correction converter described above, the second rectifier circuit includes a diode and a capacitor connected to one end of the second winding of the choke coil, and the third rectifier circuit includes the choke coil. It may consist of a diode and a capacitor connected to the other end of the second winding.

  With such a configuration, a DC voltage is applied to the first winding of the choke coil to rectify both positive and negative voltage power induced in the second winding into DC power, and a constant voltage without a valley portion. It becomes possible.

  Another power factor improving converter according to the present invention transmits a first rectifier circuit that rectifies externally supplied AC power to DC power, and transmits DC power rectified by the first rectifier circuit only in one direction. A transmission circuit to be turned on, an inrush prevention element for preventing the inrush of power to the transmission circuit by making the transmission circuit conductive when a voltage is applied to a predetermined gate, and turning on / off the DC power transmitted by the transmission circuit. A switching element that is turned off and applied to the first (primary) winding of the choke coil is magnetically coupled to the choke coil separately from the first (primary) winding, and the switching element is turned off. Sometimes induced by a third (element driving) winding that applies a positive voltage to the gate of the inrush prevention element and by the second (secondary) winding when the switching element is on-controlled. A second rectifier circuit that rectifies and outputs positive voltage power to DC power; and rectifies negative voltage power induced by the second winding to DC power when the switching element is turned off. And a third rectifier circuit for outputting.

  With such a configuration, a sufficient voltage can be applied to the gate of the thyristor or the like when starting to turn on, thereby enabling a smooth operation by the power factor correction converter. Also, it becomes possible to rectify and output the power of both positive and negative voltages induced when the on / off control is performed by the switching element using the second rectifier circuit and the third rectifier circuit, to DC power, A voltage induced by the second (secondary) winding by applying DC power to the first (primary) winding of the choke coil is a constant voltage without a valley portion.

  The power factor correction converter according to the present invention can supply stable power with less pulsating flow to an external circuit, and can stably operate a transmission circuit that transmits power from the outside. The effect of becoming is obtained.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an explanatory diagram illustrating a configuration example of a power factor correction converter 100 according to an embodiment. The power factor improving converter 100 is a switching converter that rectifies AC power supplied from the outside such as a commercial power source into DC power, and outputs DC power (VH) boosted by switching an inductor (winding). The configuration of each part of the power factor correction converter 100 will be described.

  The power factor correction converter 100 includes a diode bridge DB that rectifies an AC supplied from an AC power supply AC such as a commercial power supply provided outside. The diode bridge DB is composed of, for example, four diodes, and has a function of rectifying AC power from the AC power supply AC and outputting it as DC power to the thyristor TH.

  The power factor correction converter 100 includes a choke coil L1 having windings W1 and W2 wound at a predetermined turn ratio. The choke coil L1 has one end (end of winding) of the winding W1 connected to the thyristor TH and the other end (start of winding) connected to a switching element Q1 such as a MOSFET (MOS field effect transistor). One end of the winding W <b> 2 is connected to the rectifier circuit 10, and the other end is connected to the rectifier circuit 20. Such a winding W2 is used for generating an auxiliary power source, and switching control of the switching element Q1 is performed using the auxiliary power source. The switching element Q1 performs on / off control of transmission of DC power to the choke coil L1, for example, by PWM control.

The choke coil L1 induces, on the winding W2 side, AC power having a voltage corresponding to the turn ratio between the winding W1 and the winding W2 when the DC power transmitted through the thyristor TH is input to the winding W1. And has a function of outputting to the rectifier circuit 10 and the rectifier circuit 20. The winding W2 of the choke coil L1 induces a positive voltage _VW2B when the switching element Q1 controls the transmission of DC power, and generates a sinusoidal pulse waveform voltage as shown in the waveform diagram of FIG. When the switching element Q1 outputs to the circuit 20 and the switching element Q1 turns off the transmission of the DC power, the negative voltage _VW2A is induced to generate a bridge-like pulse waveform voltage as shown in the waveform diagram of FIG. Output. Note that the sum of the electric power obtained by rectifying both positive and negative voltages controlled by the switching element Q1 by the rectifier circuit 10 and the rectifier circuit 20 is a constant voltage with no pulsating flow as shown in the waveform diagram of FIG.

  The choke coil L1 is magnetically coupled with, for example, a winding W3 wound around a core coaxial with the winding W1. This winding W3 induces a positive voltage when the switching element Q1 turns off the transmission of DC power, generates a bridge-shaped pulse waveform voltage and applies it to the thyristor TH as shown in the waveform diagram of FIG. To do.

  The thyristor TH has an anode connected to the diode bridge DB, a gate connected to one end (winding start) of the winding W3 of the choke coil L1, and a cathode connected to the other end (winding end) of the winding W3.

When the power factor correction converter 100 is activated, an inrush current flows to the output capacitor Co through the resistor R1 bypassing the thyristor TH, and after the output capacitor Co is charged to some extent, the control circuit IC1 and the switching element Q1 start operating, The voltage _VW3 induced in the element driving winding W3 according to the turn ratio between W1 and the winding W3 is applied to the gate as a trigger voltage, and the thyristor TH is turned on. As a result, DC power can be transmitted from the diode bridge DB as a steady operation. Further, resistors R2 and R3 for voltage adjustment are connected around the thyristor TH and on a connection line to the element driving winding W3. A triac capable of transmitting DC power when turned on instead of the thyristor TH may be used.

The switching element Q1 has a process for comparing the voltage V _{DB of the} DC power rectified by the diode bridge DB and the voltage V _IS detected by the resistor R4 connected between the switching element Q1 and the diode bridge DB. A control circuit IC1 for performing is connected. The switching element Q1 receives the PWM control signal from the control circuit IC1 and controls on / off of transmission of DC power from the diode bridge DB to the choke coil L1 through the thyristor TH, and the waveform of the input current to the choke coil L1. Is switched so that the output voltage VH becomes a constant value.

The power factor correction converter 100 includes a rectifier circuit 10 including a diode D1 and a capacitor CA connected to one end (winding start) of the winding W2 of the choke coil L1. The rectifier circuit 10 rectifies the negative voltage _VW2A induced in the winding W2 from the AC power to the DC power when the switching element Q1 controls the transmission of the DC power to OFF, and outputs the rectified circuit to the series regulator SR.

The power factor correction converter 100 includes a rectifier circuit 20 including a diode D2 and a capacitor CB connected to the other end (end of winding) of the winding W2. The rectifier circuit 20 rectifies the positive voltage _VW2B induced by the winding W2 from the AC power to the DC power when the switching element Q1 turns on the transmission of the DC power, and outputs it to the series regulator SR.

  The series regulator SR adjusts the DC power transmitted through the rectifier circuit 10 and the rectifier circuit 20 to a constant voltage, and supplies it as auxiliary power as described above.

  Next, the operation of the power factor correction converter 100 of one embodiment will be described. When the power factor correction converter 100 is operated and the switching element Q1 is turned on by receiving the PWM control signal from the control circuit IC1, the DC power rectified by the diode bridge DB is input to the winding W1 through the thyristor TH. The

In the choke coil L1, the AC power of the positive voltage V _W2B that is stepped down (or boosted) in accordance with the turn ratio between the winding W1 and the winding W2 by the winding W2 in accordance with the input of DC power to the winding W1. Induced and output to the rectifier circuit 20. The AC power of the positive voltage _VW2B has a sinusoidal pulse waveform as shown in FIG. The AC power output to the rectifier circuit 20 is rectified to DC power here, and is transmitted in the order of points P ₄ -P ₃ -P ₅ -P ₆ -P ₁ -P ₂ (forward) to pass through the series regulator SR. Output for assistance.

  Next, when the switching element Q1 is turned off by receiving the control signal from the control circuit IC1 and switching the input voltage to the choke coil L1, the DC power rectified by the diode bridge DB is converted into the choke coil L1. Is not transmitted to the winding W1.

In the choke coil L1, since direct current power is not input to the winding W1, the alternating current power of the negative voltage V _W2A corresponding to the turn ratio of the winding W1 and the winding W2 is induced by the winding W2, and is output to the rectifier circuit 10. Is done. The AC power of the negative voltage _VW2A has a bridge-like pulse waveform as shown in FIG. The AC power output to the rectifier circuit 10 is rectified to DC power here, and transmitted in the order of points P ₁ -P ₂ -P ₃ -P ₄ -P ₁ -P ₂ (flyback), and the series regulator SR. Is output for assistance.

  The series regulator SR supplies, as auxiliary power, power obtained by summing both positive and negative DC power generated during the on / off control in the switching element Q1 output from the rectifier circuit 10 and the rectifier circuit 20. . As a result, as shown in FIG. 2, the power obtained by summing the DC power of both positive and negative voltages becomes a DC power of a constant voltage that combines the sine wave pulse waveform and the bridge pulse waveform. It is supplied as stable constant voltage power.

In the choke coil L1, a trigger voltage _VW3 corresponding to the turn ratio of the winding W1 and the winding W3 is induced by the element driving winding W3 wound around the core coaxial with the winding W1. Applied to the gate of thyristor TH. As shown in FIG. 3, this trigger voltage has a bridge-like pulse waveform because it becomes a positive voltage when the switching element Q1 is turned off. As shown in FIG. 3, since the trigger voltage at the beginning of the current waveform flowing through the thyristor TH, that is, the trigger voltage at the phase angle of 0 ° or 180 ° is the highest voltage, it is sufficient to turn on the thyristor TH with respect to the gate. Voltage. For this reason, the thyristor TH can be activated quickly from the start of the operation of the power factor correction converter 100, and the steady operation of the power factor correction converter 100 is smoothly performed.

As described above, in power factor correction converter 100 according to the present embodiment, switching element Q1 is controlled to be on, DC power is input to winding W1 of choke coil L1, and positive voltage V _W2B induced by winding W2 is applied. DC power of both the positive and negative voltages using the power of the negative voltage _VW2A induced by the winding W2 without the DC power being input to the winding W1 of the choke coil L1 because the switching element Q1 is turned off. The electric power having a constant voltage obtained by summing the electric power is output for assistance through the series regulator SR. In addition, in the winding W3 wound around the core coaxial with the winding W1, when the switching element Q1 is controlled to be off, a trigger voltage having a bridge-like pulse waveform is induced, and a phase angle 0 of the input current is induced. At a time of 180 degrees and 180 degrees, a sufficient voltage is applied to the gate of the thyristor TH to prevent malfunction of the thyristor TH.

  For this reason, since the valley portion generated by the voltage waveform becoming the switching waveform is eliminated as in the power factor improving converter 200 in the prior art, the voltage is not greatly reduced, and the constant voltage is stabilized for auxiliary use. Power can be supplied. In addition, since it is possible to prepare and operate the choke coil L1 in which the turns ratio of the windings W1 and W2 is set so that the minimum peak voltage power can be obtained, a high voltage power is induced in advance. This eliminates the need to set the turns ratio. As a result, the loss of the series regulator SR can be minimized, and since the auxiliary power has no voltage pulsation, the capacities of the capacitors CA and CB of the rectifier circuits 10 and 20 can be configured to a minimum. it can.

  Further, in the thyristor TH, the winding W3 is connected in the opposite polarity to the power factor improvement converter of the prior art, and a trigger voltage having a bridge-like pulse waveform is applied, so that the power factor improvement converter 200 in the prior art is applied. Since the trigger voltage waveform becomes a switching waveform, the voltage does not drop greatly at the start of turning on of the thyristor TH, so that the thyristor TH can be operated smoothly. For this reason, the choke coil L1 in which the turns ratio of the windings W1 and W3 is set so that the minimum voltage necessary to turn on the thyristor TH is induced at the phase 0 degree or around 180 degrees of the waveform diagram shown in FIG. Therefore, it is possible to reduce the loss of the gate resistors R1, R2 and R3 connected to the periphery of the thyristor TH.

[Other Embodiments]
In the above-described embodiment, the winding W3 may be eliminated by using a thermistor or the like capable of transmitting DC power rectified by the diode bridge DB instead of the thyristor TH.

  Further, in the above-described embodiment, the polarity of the winding W3 may be the same as in the prior art (FIG. 4), and a positive voltage may be induced when the switching element Q1 is controlled to be on. In this case, the loss of the series regulator SR can be reduced.

  In the above-described embodiment, the winding W2 and its rectifier circuit portion may be omitted, and an auxiliary external power supply device may be used instead. In this case, it is possible to reduce the loss of the drive circuit such as thyristor TH or triac.

  Furthermore, in the above-described embodiment, the winding W2 and its rectifier circuit portion may be the same as the conventional one (FIG. 4). Also in this case, the loss of the drive circuit such as the thyristor TH or triac can be reduced.

It is explanatory drawing which shows the structure of the power factor improvement converter of one Embodiment. It is a wave form diagram which shows the voltage waveform of the electric power induced by the coil | winding W2 of a power factor improvement converter. It is a wave form diagram which shows the voltage waveform induced with the coil | winding W3 of a power factor improvement converter. It is explanatory drawing which shows the structure of the power factor improvement converter of a prior art. It is a wave form diagram which shows the voltage waveform of the electric power induced by the coil | winding W2 of the power factor improvement converter of a prior art. It is a wave form diagram which shows the voltage waveform induced with the coil | winding W3 of the power factor improvement converter of a prior art. It is a clear diagram.

Explanation of symbols

10, 20 Rectifier circuit 100 Power factor improving converter AC AC power supply DB Diode bridge IC1 Control circuit L1 Choke coil Q1 Switching element SR Series regulator TH Thyristor W1 Primary winding (main winding, first winding)
W2 Secondary winding (second winding)
W3 Element drive winding (3rd winding)

Claims (7)

A first rectifier circuit that rectifies AC power supplied from the outside into DC power;
A transmission circuit for transmitting DC power rectified by the first rectifier circuit;
An inrush prevention element that prevents the inrush of electric power to the transmission circuit by making the transmission circuit conductive when a voltage is applied to a predetermined gate,
A switching element that applies on / off control of the DC power transmitted by the transmission circuit to the main winding of the choke coil;
A power factor correction converter comprising: an element driving winding magnetically coupled to the choke coil and connected to a gate of the inrush prevention element in a state wound in a direction opposite to the main winding . A first rectifier circuit that rectifies AC power supplied from the outside into DC power;
A transmission circuit for transmitting DC power rectified by the first rectifier circuit;
An inrush prevention element that prevents the inrush of electric power to the transmission circuit by making the transmission circuit conductive when a voltage is applied to a predetermined gate,
A switching element that applies on / off control of the DC power transmitted by the transmission circuit to the main winding of the choke coil;
In addition to the main winding, an element driving winding that is magnetically coupled to the choke coil and applies a positive voltage to the gate of the inrush prevention element when the switching element is off-controlled. The power factor improvement converter which is characterized. The power factor correction converter according to claim 1 or 2,
The element driving winding is:
A power factor correction converter, wherein the converter is wound around a core coaxial with the main winding, one end of which is connected to the gate of the inrush prevention element and the other end is connected to the transmission circuit. The power factor correction converter according to claim 3,
The transmission circuit is
The thyristor is characterized in that the gate is connected to one end of the element driving winding, the anode is connected to the first rectifier circuit, and the cathode is connected to the other end of the element driving winding. Power factor improvement converter. A first rectifier circuit that rectifies AC power supplied from the outside into DC power;
A switching element that controls on / off of the DC power rectified by the first rectifier circuit and applies the DC power to the first winding of the choke coil;
A second rectifier circuit that rectifies and outputs a positive voltage power induced by the second winding of the choke coil to a DC power when ON-controlled by the switching element;
And a third rectifier circuit that rectifies and outputs a negative voltage power induced by the second winding of the choke coil to a DC power when the switching element is turned off. Rate improvement converter. The power factor correction converter according to claim 5,
The second rectifier circuit includes a diode and a capacitor connected to one end of the second winding of the choke coil,
The power factor correction converter according to claim 3, wherein the third rectifier circuit includes a diode and a capacitor connected to the other end of the second winding of the choke coil. A first rectifier circuit that rectifies AC power supplied from the outside into DC power;
A transmission circuit for transmitting DC power rectified by the first rectifier circuit only in one direction;
An inrush prevention element that prevents the inrush of electric power to the transmission circuit by making the transmission circuit conductive when a voltage is applied to a predetermined gate,
A switching element that applies on / off control of the DC power transmitted by the transmission circuit to the first winding of the choke coil;
A third winding that is magnetically coupled to the choke coil separately from the first winding and applies a positive voltage to the gate of the inrush prevention element when the switching element is off-controlled;
A second rectifier circuit for rectifying and outputting positive voltage power induced by the second winding to DC power when the switching element is on-controlled;
A power factor correction converter comprising: a third rectifier circuit that rectifies negative voltage power induced by the second winding into DC power when the switching element is off-controlled and outputs the DC power .

Images