WO2013164896A1

WO2013164896A1 - Current suppressing circuit, power supply circuit, power supply apparatus, semiconductor circuit, and load circuit substrate

Info

Publication number: WO2013164896A1
Application number: PCT/JP2012/061617
Authority: WO
Inventors: 浩島森
Original assignee: 富士通株式会社
Priority date: 2012-05-02
Filing date: 2012-05-02
Publication date: 2013-11-07
Also published as: JPWO2013164896A1

Abstract

The present invention suppresses a rapid increase of a charge current to a capacitor. A current suppressing circuit (10) is provided between a power supply section (12), which outputs a direct current voltage, and a load (14), which operates by means of the direct current voltage outputted from the power supply section. The current suppressing circuit has a capacitor (18) and a polarized coil (20) connected in series. The polarized coil includes a core, in which a magnetic field wherein magnetic density (B) has become saturated magnetic density (Bs) due to a permanent magnet is formed, and a coil (24) that is wound on the core. When charging of the capacitor is started by having a power supply switch (16) turned on, and a charge current (Ic) flowing in the coil becomes equal to or more than a current (Is), inductance of the polarized coil is increased. The polarized coil suppresses a rapid increase and the peak current of the charge current by means of impedance corresponding to the inductance.

Description

Current suppression circuit, power supply circuit, power supply device, semiconductor circuit, and load circuit board

The present invention relates to a current suppression circuit, a power supply circuit, a power supply device, a semiconductor circuit, and a load circuit board.

Conventionally, a current limiter that restricts the flow of a large current to the coil by providing a permanent magnet or an electromagnet in a part of the core and saturating the magnetic density of the core has been proposed. Further, as a technique using a current limiter, a technique for suppressing the discharge current of a capacitor provided inside the apparatus has been proposed. In this technique, when the power supply from the power supply line is stopped due to a short circuit or the like, the discharge current from the capacitor is suppressed to prevent the power stored in the capacitor from being discharged to the power supply line.

On the other hand, the power supply device rectifies the AC voltage with a rectifier circuit and then smoothes it using an electrolytic capacitor or the like to convert it to a DC voltage and supplies it to the load device. In such a power supply device, when the power switch is turned on and voltage application to the capacitor is started, the current value of the capacitor charging current instantaneously increases, and an inrush current is generated in the input current of the power supply device.

As a technique for suppressing the inrush current, there is a technique for providing an impedance component such as an inrush current suppressing resistor on the output side of the rectifier circuit. With this technique, inrush current can be suppressed, but power is consumed by the impedance component even in a steady state.

From here, there is a technology in which a switch is provided in parallel with the resistor for suppressing the inrush current, and the switch is closed in a steady state so that power is not consumed by the impedance component. However, in this technique, since the impedance component disappears at the moment when the switch is closed, the voltage applied to the capacitor may rise and cause an inrush current.

Furthermore, as a technique for suppressing the inrush current to the capacitor, a technique for suppressing the inrush current at the time of charging the capacitor by providing an impedance component for the charging current of the capacitor has been proposed. However, in the proposed technique, an impedance component always acts on the charging current of the capacitor.

JP 09-168281 A JP 2001-238349 A JP 2004-201369 A JP 2010-263709 A

In one aspect, an object of the present invention is to suppress generation of an inrush current due to a voltage applied to a capacitor.

In one scheme, the capacitor accumulates charge with a charging current according to the applied DC voltage. The bias coil includes a coil connected in series to the capacitor, a core around which the coil is wound, and a magnetizing member that forms a magnetic field in the core with a saturation magnetic flux density inside the core. Further, the inductance of the magnetically biased coil increases when the charging current flowing through the coil becomes a predetermined value or more.

It has the effect that generation | occurrence | production of the inrush current by the voltage applied to the capacitor rising can be suppressed.

It is a circuit diagram which shows the current suppression circuit in the technique of an indication. It is a perspective view which shows an example of the magnetic bias coil in the technique of an indication. It is a diagram which shows the DC superimposition characteristic of a BH characteristic, a non-biased coil, and a biased coil. It is a diagram which shows the change of the voltage applied to a current suppression circuit. It is a diagram which shows the change of the input current to a current suppression circuit. It is a circuit diagram which shows the other aspect of the current suppression circuit in the technique of an indication. It is a circuit diagram of the principal part which shows an example of the power supply device which concerns on 1st Embodiment. It is a diagram which shows the change of the alternating voltage, the input current, and the capacitor voltage at the time of the momentary power failure in the case of providing the magnetizing coil. It is a diagram which shows the change of the alternating voltage, the input current, and the capacitor voltage at the time of the momentary power failure when not providing the magnetizing coil. It is a circuit diagram of the principal part which shows an example of the power supply device which concerns on 2nd Embodiment. It is a diagram which shows the change of the alternating voltage in the power supply device which concerns on 2nd Embodiment, an input current, and a capacitor voltage. It is a diagram which shows the change of an alternating voltage, an input current, and a capacitor voltage when not providing the magnetizing coil in the power supply device which concerns on 2nd Embodiment. It is a circuit diagram of the principal part which shows an example of the power supply device which concerns on 3rd Embodiment. It is a block diagram which shows an example of the other aspect in the technique of an indication.

Hereinafter, the principle of the disclosed technology will be described prior to the description of the embodiment of the disclosed technology. FIG. 1 shows a current suppression circuit 10. The current suppression circuit 10 is provided between the power supply unit 12 and a load 14 supplied with power from the power supply unit 12. The power supply unit 12 supplies a predetermined DC voltage Vd to the load 14 when the contact is closed by turning on the power switch 16.

The current suppression circuit 10 includes a capacitor 18 such as an electrolytic capacitor. The capacitor 18 is connected in parallel with the load 14 on the load 14 side of the power switch 16 by connecting one of the pair of terminals to the + side of the power supply unit 12 and the other connected to the − side of the power supply unit 12. ing. The capacitor 18 has a function of accumulating charges according to the voltage applied between the pair of terminals.

In the current suppression circuit 10, a magnetic bias coil 20 is connected in series with the capacitor 18 to the positive terminal of the capacitor 18.

As shown in FIG. 2, the magnetic bias coil 20 includes a core 22 formed using a magnetic material, and a coil 24 generated by winding an electric wire around the core 22.

A known material can be applied as the material of the core 22. The core 22 is not limited to an annular shape, and any shape such as a quadrangle having a hollow portion formed inside can be applied.

A part of the core 22 formed in an annular shape is excised, and a permanent magnet 26 as a magnetizing member is fitted into the excised part to form a closed magnetic circuit. The magnetically biased coil 20 may be any one as long as a member that forms the core 22 and a member that forms the permanent magnet 26 are connected so as to form a magnetic loop. In addition, as the magnetizing member, a member that forms a predetermined magnetic field on the core 22 can be applied.

1 and 2, the current that flows through the coil 24 of the magnetic bias coil 20 when the capacitor 18 is charged is the charging current Ic.

FIG. 3 shows a BH characteristic curve of a general coil (hereinafter referred to as a non-biased coil) without the permanent magnet 26 and a bias coil 20, and a DC superposition characteristic which is a characteristic of inductance with respect to current. Is shown. In the DC superposition characteristics of FIG. 3, the characteristics of the biased coil 20 are indicated by solid lines, and the characteristics of the non-biased coils are indicated by broken lines.

In the core 22, magnetic field H is applied by the permanent magnet 26, so that magnetic flux is generated even when no current flows through the coil 24. The magnetic flux density B inside the core 22 changes depending on the direction and strength of the magnetic field H, and by increasing the magnetic field H, the magnetic flux density B increases.

The permanent magnet 26 provided in the biased coil 20 saturates the magnetic flux density B inside the core 22 even when no current flows through the coil 24. When the magnetic flux density B is saturated, a permanent magnet 26 forms a magnetic flux in one direction inside the core 22, and a current flows through the coil 24 to increase the magnetic flux in the same direction. Indicates that there is no room to increase. The magnetic flux density B at this time becomes the saturation magnetic flux density Bs. Since the magnetic flux density B in the core 22 has reached the saturation magnetic flux density Bs, the magnetic flux does not increase even if the magnetic field H is increased.

As shown in FIG. 2, when the saturation magnetic flux density Bs is reached by the magnetic flux in the arrow B direction inside the core 22, the magnetic flux (magnetic flux density B) inside the coil 22 does not increase. At this time, the inductance L of the coil 24 is extremely low. Therefore, even if a current flows in the coil 24 in the direction of increasing the magnetic flux (from the negative side to the positive side), no impedance for this current appears. In FIG. 2, the direction of the charging current Ic is indicated by an arrow Ic.

As shown in FIG. 2, the coil 24 of the bias coil 20 is wound around the core 22 in a direction in which a magnetic flux opposite to the magnetic flux generated by the permanent magnet 26 is generated when the charging current Ic flows from the positive side to the negative side. It has been turned. When a current (charging current Ic) flows through the coil 24, a magnetic field in a direction that reduces the magnetic flux density B is generated. At this time, the coil 24 maintains a low inductance L until the magnetic field inside the core 22 reaches a magnetic field at which the magnetic flux density B is less than the saturation magnetic flux density Bs.

In the core 22, when the strength of the magnetic field becomes a value at which the magnetic flux density B is less than the saturation magnetic flux density Bs, a magnetic flux in a direction to decrease the magnetic flux density B is generated. By generating a magnetic flux in the direction of decreasing the magnetic flux density B inside the core 22, the inductance L of the magnetic bias coil 20 is greatly increased. The inductance L acts as an impedance with respect to the change in the charging current Ic of the coil 24 and suppresses the change in the charging current Ic.

That is, in the magnetically biased coil 20, when the inductance L increases, a counter electromotive force is generated with respect to the charging current Ic, and an increase in the charging current Ic is suppressed by the counter electromotive force.

The magnetized coil 20 is provided with a permanent magnet 26 so that the core 22 has a saturation magnetic flux density Bs until the current reaches a predetermined value (hereinafter referred to as current Is) with respect to the charging current Ic in the direction of the arrow Ic. Yes. Thus, when the charging current Ic flowing through the coil 24 increases, the permanent magnet 26 forms a magnetic field H that maintains the inside of the core 22 at the saturation magnetic flux density Bs until the charging current Ic reaches the current Is.

Further, when the charging current Ic increases and exceeds the current Is, the magnetic flux density B of the core 22 that has been set to the saturation magnetic flux density Bs by the permanent magnet 26 is decreased. Thereby, the inductance L of the magnetic bias coil 20 increases significantly. The magnetic bias coil 20 suppresses an increase in the charging current Ic by an impedance corresponding to the inductance L.

As described above, the current suppression circuit 10 has a DC superimposition characteristic of the magnetic bias coil 20 with respect to a DC superimposition characteristic of the non-magnetic coil so that an inductance L is generated in the magnetic bias coil 20 when the charging current Ic exceeds the current Is. Shift.

In FIG. 3, the current Is is set so that the direct current superimposition characteristic of the non-biased coil and the direct current superimposition characteristic of the magnetic bias coil 20 do not overlap, but this is not restrictive. Any method may be used as long as the inductance L of the magnetic bias coil 20 is increased by a preset current Is or more. For example, it includes setting the current Is so that the direct current superimposition characteristic of the non-biased coil and the direct current superimposition characteristic of the magnetic bias coil 20 overlap.

FIG. 4 shows a change in voltage applied between the terminals of the capacitor 18 (hereinafter referred to as capacitor voltage Vc), and FIG. 5 shows a change in the charging current Ic by turning on the power switch 16. ing. 4 and 5, the voltage change and the current change in the current suppression circuit 10 provided with the magnetic bias coil 20 are shown by solid lines, and the voltage change of the capacitor voltage and the charging current when the magnetic bias coil 20 is removed are shown. The change in current is indicated by a broken line.

As shown in FIG. 4, in the current suppression circuit 10, when the power switch 16 is turned on, electric charge is accumulated in the capacitor 18, and a capacitor voltage Vc corresponding to the accumulated electric charge is generated. That is, the capacitor 18 accumulates electric charges so that the capacitor voltage Vc matches the applied voltage. At this time, in the case where the magnetic bias coil 20 is provided, the voltage change is moderate as compared with the case where the magnetic bias coil 20 is not provided.

As shown by a broken line in FIG. 5, when the magnetic bias coil 20 is not provided, the charging current Ic increases rapidly immediately after the power switch 16 is turned on. The charging current Ic decreases when it reaches a peak value (peak current). The peak current Ipa of the charging current Ic is determined by impedance components such as the impedance of the power supply unit 12 and circuit resistance. Since this impedance component is low because it causes unnecessary power consumption, the peak current Ipa has a very high current value. Therefore, an rush current that becomes a surge current having a very large current value is generated in the input current In immediately after the power switch 16 is turned on.

On the other hand, in the current suppression circuit 10 including the biased coil 20, the charging current Ic increases rapidly immediately after the power switch 16 is turned on. However, in the current suppression circuit 10, when the charging current Ic reaches the current Is, the inductance L of the magnetic bias coil 20 increases, and an impedance corresponding to the inductance L is generated, so that the slope of the charging current Ic rises gradually. It becomes. Therefore, the current suppression circuit 10 can suppress the peak current Ipb of the charging current Ic to be lower than the peak current Ipa. This peak current Ipb is determined by the inductance L of the magnetic bias coil 20, and by increasing the inductance L, the peak current Ipb can be lowered.

Therefore, in the current suppression circuit 10, the capacitor voltage Vc gradually increases as compared with the case where the bias coil 20 is not provided, but the input current caused by the charging current Ic when the power switch 16 is turned on. The inrush current of In can be suppressed.

In the current suppression circuit 10, the peak current Ipb and the current Is are set based on the allowable range of the inrush current generated in the input current In, and the inductance L of the magnetic bias coil 20 is set based on the set peak current Ipb and current Is. To do. As a result, the current suppression circuit 10 can prevent an inrush current from occurring in the input current In due to an increase in the charging current Ic of the capacitor 18.

The magnetic bias coil 20 can be connected in series with the load 14. In the current suppression circuit 10 A shown in FIG. 6, the bias coil 20 connected in series to the capacitor 18 is also connected in series to the load 14. In the current suppression circuit 10 A, the current that has passed through the magnetic bias coil 20 flows to the load 14 and the capacitor 18.

In the current suppression circuit 10A, it is necessary to set the current Is in consideration of the current flowing through the load 14. However, also in the current suppression circuit 10A, when the voltage applied to the capacitor 18 increases, the increase in the charging current Ic can be suppressed. Thereby, also in the current suppression circuit 10 A, similar to the current suppression circuit 10, it is possible to suppress a rapid increase in the input current In due to the inrush current.

Embodiments of the disclosed technology will be described below.

[First embodiment]

FIG. 7 shows the power supply device 30 according to the first embodiment of the disclosed technique. The power supply device 30 includes a power switch 32 and a fuse 34, and an AC power supply 36 such as a commercial power supply is connected via the power switch 32 and the fuse 34. The power supply device 30 is supplied with AC power of a predetermined voltage (hereinafter referred to as AC voltage Vac) from the AC power source 36 by turning on the power switch 32 (closing the contact).

The power supply device 30 includes a rectifying circuit 38 that rectifies the AC voltage Vac and a smoothing circuit 40 that smoothes the voltage rectified by the rectifying circuit 38. The power supply device 30 smoothes the voltage rectified by the rectifier circuit 38 by passing through the smoothing circuit 40.

The resistor 42 is a discharge resistor provided to discharge the electric charge of the capacitor 18 when the power switch 32 and the switch 46 are opened. The load 44 includes a switch 46. The power supply device 30 supplies power of a predetermined DC voltage Vin to the load 44 when the switch 46 of the load 44 is turned on. The load 44 operates according to the power supplied from the power supply device 30 and thereby consumes power according to the impedance RL.

In the power supply device 30, a current including the current corresponding to the power consumed by the load 44 (hereinafter referred to as input current In) flows through the fuse 34. The fuse 34 blows when the input current In exceeds the allowable current value, and cuts off the power supply to the rectifier circuit 38 and the subsequent parts.

In the disclosed technology, the load 44 does not include the switch 46, and includes the electric device that is turned on / off by the power switch 32 by integrating the power supply device 30 and the load 44. That is, in the disclosed technology, the load 44 may be an electric device including the power supply device 30.

In the first embodiment, the smoothing circuit 40 is an example of a current suppression circuit in the disclosed technology, and the power supply device 30 including the smoothing circuit 40 is an example of a power supply device and a power supply circuit in the disclosed technology.

The rectifier circuit 38 has four diodes 48 connected in a bridge manner, and full-wave rectifies and outputs the input AC voltage Vac. The disclosed technology is not limited to full-wave rectification but may be half-wave rectification. The power supply device 30 can also include a transformer that converts the AC voltage Vac input from the AC power supply 36 into a predetermined voltage. By including a transformer, the power supply device 30 boosts or steps down the input AC voltage Vac, converts it to a desired voltage, and outputs it. Further, in the disclosed technique, a DC voltage source that outputs a DC voltage can be used instead of the AC power supply 36 and the rectifier circuit 38.

The smoothing circuit 40 includes a capacitor 18. In the power supply device 30, one terminal side of the capacitor 18 is the positive side (+ side), and the other terminal is connected to the negative side (− side). In the smoothing circuit 40, the capacitor 18 is connected in parallel with the load 44 as viewed from the rectifier circuit 38 side.

The smoothing circuit 40 includes the biased coil 20. The magnetic bias coil 20 is connected to the positive terminal of the capacitor 18 so as to be in series with the capacitor 18. In the smoothing circuit 40, the capacitor 18 and the bias coil 20 connected in series are integrally connected in parallel to the load 44. The magnetic bias coil 20 may be inserted into the negative terminal of the capacitor 18.

The biasing coil 20 is supplied with a charging current Ic corresponding to the charge accumulated in the capacitor 18 and a current (discharge current) corresponding to the charge released from the capacitor 18. The charging current Ic for charging the capacitor 18 is included in the input current In of the power supply device 30.

In the disclosed technology, in the smoothing circuit 40, the biased coil 20 does not function as an impedance with respect to the discharge current by using the biased coil 20. In the disclosed technique, the magnetic bias coil 20 does not function as an impedance with respect to the charging current Ic until the charging current Ic reaches the current Is.

On the other hand, in the magnetically biased coil 20, when the charging current Ic rapidly increases and exceeds the current Is, a magnetic flux is generated in a direction that cancels the magnetic flux in the core 22, and the inductance L is greatly increased. Thereby, the magnetic bias coil 20 becomes an impedance with respect to the charging current Ic that is rapidly increased, and suppresses an increase in the charging current Ic.

The power supply device 30 suppresses the occurrence of an inrush current in the input current In by suppressing a rapid increase in the charging current Ic. The power supply device 30 prevents the inrush current from being generated in the input current In, thereby preventing the input current In from exceeding the protection current (blown current) by the fuse 34 and blowing the fuse 34.

Hereinafter, the operation of the power supply device 30 will be described as an operation of the embodiment.

In the power supply device 30, the AC voltage Vac of the AC power supply 36 is input to the rectifier circuit 38 by turning on the power switch 32. The rectifying circuit 38 rectifies the AC voltage Vac and outputs it to the smoothing circuit 40. In the smoothing circuit 40, the voltage input from the rectifier circuit 38 is smoothed and output to the load 44. At this time, in the power supply device 30, the inductance L of the magnetic bias coil 20 is so small that it can be ignored, so that the capacitor voltage Vc becomes the DC voltage Vin supplied to the load 44.

Incidentally, in the power supply device 30, when the power switch 32 is turned on, charging of the capacitor 18 of the smoothing circuit 40 is started. At the start of charging of the capacitor 18, a large inrush current flows as the charging current Ic. In the power supply device 30, the inrush current of the charging current Ic is suppressed by connecting the magnetic bias coil 20 in series with the capacitor 18 of the smoothing circuit 40.

That is, as shown in FIG. 5, in the power supply device 30, since the capacitor 18 is charged immediately after the power switch 32 is turned on, the charging current Ic tends to increase rapidly.

At this time, by providing the magnetic bias coil 20, when the charging current Ic reaches the current Is, the magnetic bias coil 20 becomes an impedance with respect to the charging current Ic. Thereby, in the smoothing circuit 40 of the power supply device 30, the change of the charging current Ic becomes gentle. Thereafter, the charging current Ic starts decreasing when it reaches the peak current Ipb.

As described above, in the power supply device 30, the magnetic bias coil 20 provided in the smoothing circuit 40 suppresses an abrupt increase in current generated in the charging current Ic. Further, in the power supply device 30, by suppressing the charging current Ic to the capacitor 18, the input current In does not increase due to the inrush current and the fuse 34 is not blown.

On the other hand, in the power supply device 30, for example, the AC power that is input may be temporarily stopped due to the AC power supply 36 being stopped (hereinafter referred to as an instantaneous power failure). The power supply 30 discharges the capacitor 18 when a power failure such as an instantaneous power failure occurs. In the power supply device 30, since the power switch 36 is turned on, charging of the capacitor 18 is started immediately after the power failure is restored.

8 and 9 show changes in the AC voltage Vac, the input current In, and the capacitor voltage Vc before and after the instantaneous power failure. 8 shows a change in the power supply device 30 provided with the magnetic bias coil 20, and FIG. 9 shows a change in the power supply device obtained by removing the magnetic bias coil 20 from the power supply device 30.

As shown in FIGS. 8 and 9, when the power switch 32 is turned on and the supply of the AC voltage Vac is continued, the capacitor voltage Vc and the input current In change within a predetermined range. In FIGS. 8 and 9, the capacitor voltage Vc at this time is the voltage Vc0.

Here, when an instantaneous power failure occurs at time T from time t1 to time t2, the power supply from the AC power supply 36 is stopped. In addition, the supply of the AC voltage Vac from the AC power supply 36 is started to the power supply device 30 when the power failure of the AC power supply 36 is restored. When the supply of the AC voltage Vac is started by the power failure recovery, the power supply device 30 starts charging the capacitor 18. In the power supply device 30, the capacitor voltage Vc drops from the voltage Vc 0 (voltage drop) by discharging the capacitor 18 even in the case of an instantaneous power failure with a short power failure time.

For this reason, when the power failure is restored, the power supply device 30 starts charging the capacitor 18. At this time, the voltage applied to the capacitor 18 is increased by a voltage corresponding to a voltage drop generated at the time of a power failure. As the voltage rises, the charging current Ic increases rapidly, and the input current In increases as the charging current Ic increases.

As a result, as shown in FIG. 9, in the power supply device that does not have the bias coil 20, when the charging current Ic increases rapidly, an inrush current having a large current value (peak current Ip) occurs in the input current In. End up.

On the other hand, as shown in FIG. 8, in the power supply device 30 provided with the magnetic bias coil 20, the charging current Ic increases rapidly. However, in the power supply device 30, when the increased charging current Ic reaches the current Is, the inductance L of the magnetic bias coil 20 increases, and the impedance corresponding to the inductance L suppresses the increase in the charging current Ic and the peak current.

Thereby, in the power supply device 30, the occurrence of an inrush current in the input current In can be suppressed. Therefore, the power supply device 30 can suppress the occurrence of an inrush current that causes the fuse 34 to blow in the input current In even in the event of an instantaneous power failure.

[Second Embodiment]

Next, a second embodiment of the disclosed technique will be described. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

FIG. 10 shows a power supply device 50 according to the second embodiment. This power supply device 50 is different from the power supply device 30 in that it includes a resistor 52 for suppressing inrush current, a bypass switch 54 and a voltage detection circuit 56. The resistor 52 is connected between the rectifying circuit 38 and the magnetic bias coil 20 of the smoothing circuit 40, and the bypass switch 54 is connected in parallel to the resistor 52. The voltage detection circuit 56 detects the voltage V (DC voltage Vin) supplied to the load 44.

The power supply device 50 supplies the output of the rectifier circuit 38 to the smoothing circuit 40 and the load 44 through the resistor 52 by turning off the bypass switch 54 and opening the contact. Further, the power supply device 50 supplies the output of the rectifier circuit 38 to the smoothing circuit 40 without passing through the resistor 52 by turning on the bypass switch 54 and closing the contact. The voltage detection circuit 56 turns on the bypass switch 54 when the detected voltage V reaches a preset setting voltage Vs.

Here, when the bypass switch 54 is OFF, the voltage detection circuit 56 detects the terminal voltage of the resistor 42. The terminal voltage of the resistor 42 is the capacitor voltage Vc. The output voltage of the rectifier circuit 38 is a voltage Vr, the impedance (resistance value) of the resistor 42 is R2, and the impedance (resistance value) of the resistor 52 is R1. At this time, the capacitor voltage Vc1 when the bypass switch 52 is OFF is Vc1 = Vr · R2 / (R1 + R2). The voltage detection circuit 56 uses a set voltage Vs set based on this voltage.

Further, the voltage detection circuit 56 closes the bypass switch 54 when the voltage V reaches the set voltage Vs (V ≧ Vs). In this case, the capacitor voltage Vc2 is a voltage corresponding to the voltage Vr output from the rectifier circuit 38.

Hereinafter, the operation of the power supply device 50 will be described as an operation of the second embodiment.

In the power supply device 50, the power switch 32 is turned on while the bypass switch 54 is turned off. In the power supply device 50, the current that has passed through the resistor 52 flows to the capacitor 18 by turning on the power switch 32. As a result, the peak current of the charging current Ic of the capacitor 18 immediately after the power switch 32 is turned on is suppressed by the resistor 52. Further, the voltage detection circuit 56 turns on the bypass switch 54 when the detected voltage V reaches the set voltage Vs.

In the power supply device 50, when the bypass switch 54 is turned on, the capacitor voltage Vc increases by the voltage (Vr · R1 / (R1 + R2)) applied to the resistor 52. The voltage rise is increased by increasing the resistance value R1 of the resistor 52 that suppresses the inrush current when the power switch 32 is turned on.

In the power supply device 50, by providing the magnetizing coil 20 in the smoothing circuit 40A, it is possible to suppress a sudden increase in the charging current Ic due to a voltage change when the bypass switch 54 is turned on. In addition, the power supply device 50 prevents the charging current Ic from rapidly increasing, so that the inrush current does not appear in the input current In and the fuse 34 is not blown.

11 and 12 show changes in the AC voltage Vac, the input current In, and the capacitor voltage Vc. 11 shows a change of the power supply device 50 provided with the magnetic bias coil 20, and FIG. 12 shows a change of the power supply device obtained by removing the magnetic bias coil 20 from the power supply device 50.

As shown in FIGS. 11 and 12, charging the capacitor 18 is started by turning on the power switch 32. At this time, in the power supply device 50, since the bypass switch 54 is turned off, the capacitor voltage Vc does not increase rapidly, and the capacitor voltage Vc1 determined by the resistance value R2 of the resistor 42 and the resistance value R1 of the resistor 52 Become.

Thereafter, the voltage detection circuit 56 turns on the bypass switch 54 at the timing of time t3, whereby the capacitor voltage Vc rises to the voltage Vc2. That is, by turning on the bypass switch 52, the capacitor voltage Vc increases, and accordingly, the charging current Ic tends to increase rapidly.

Here, in the power supply device that does not have the magnetic bias coil 20, as shown in FIG. 12, a rapid increase in the charging current Ic appears as an inrush current in the input current In. At this time, the peak current Ip of the input current In becomes an extremely large current value because the impedance due to the resistor 52 disappears.

In contrast, in the power supply device 50, the charging current Ic is increased by turning on the bypass switch 54. In the power supply device 50, when the charging current Ic reaches the current Is, the inductance L of the magnetically biased coil 20 increases, and the rapid increase of the charging current Ic is suppressed by the impedance corresponding to the inductance L. Further, by suppressing the rapid increase in the charging current Ic, the peak current Ipb when the capacitor voltage Vc reaches the voltage Vc2 can be suppressed low. Thereby, as shown in FIG. 11, it can suppress that an inrush current arises in the input current In.

In the power supply device 50, the current Is can be reduced in order to suppress an inrush current due to a voltage change when the bypass switch 54 is turned on to bypass the resistor 52. Therefore, the magnetic force of the permanent magnet 26 provided on the core 22 can be reduced.

In addition, when a power failure such as an instantaneous power failure occurs, the power supply device 50 flows a charging current Ic for charging the capacitor 18 when the power failure is restored. In the power supply device 50, the inrush current resulting from the increase in the charging current Ic at the time of restoration of a power failure such as an instantaneous power failure can be suppressed by providing the magnetic bias coil 20.

[Third embodiment]

Next, a third embodiment of the disclosed technology will be described. In the third embodiment, the same parts as those in the first or second embodiment are denoted by the same reference numerals, and the description thereof is omitted.

FIG. 13 shows a power supply device 60 according to a third embodiment of the disclosed technology. The power supply device 60 is different from the power supply device 50 according to the second embodiment in that it includes a power factor improving unit.

The power supply device 60 includes a PFC (Power Factor Control) circuit 62 as a power factor improvement unit. The PFC circuit 62 includes a choke coil 64, a diode 66, a switching element 68, and a PFC control unit 70. As the switching element 68, for example, a MOS-FET can be used, but not limited to this, a known semiconductor element can be used.

The PFC circuit 62 has a choke coil 64 and a diode 66 connected in series on the load side of the resistor 52 and the bypass switch 54. The choke coil 64 in the disclosed technique is a non-biased coil, and a known coil can be applied. The diode 66 may be a known rectifying element that can regulate the current direction.

In the switching element 68, the drain D is connected between the choke coil 64 and the diode 66, and the source S is connected to the negative side of the rectifier circuit 38. The PFC control unit 70 drives the switching element 68 on / off by inputting a switching signal to the gate G of the switching element 68.

The smoothing circuit 40B provided in the power supply device 60 includes a PFC circuit 62 to form a so-called active smoothing filter. The PFC control unit 70 detects the output voltage and output current of the rectifier circuit 38, and generates a switching signal for driving the switching element 68 on / off based on the detected output current and input current. At this time, the PFC control unit 70 sets the duty ratio of the switching signal so that the phase of the waveform of the output current matches the phase of the waveform of the output voltage, and drives the switching element with the set duty ratio.

Thereby, in the power supply device 60, the phase of the input current In is matched with the phase of the AC voltage Vac. A known general configuration can be applied to the PFC circuit 62. The power factor improving unit provided in the power supply device 60 is not limited to the PFC circuit 62, and a known technique for matching the phase of the input current In to the phase of the AC voltage Vac input to the power supply device 60 can be applied. .

Hereinafter, the operation of the power supply apparatus 60 will be described as an operation of the third embodiment.

In the power supply device 60 as well, similarly to the power supply device 50, the power switch 32 is turned on while the bypass switch 52 is turned off. At this time, the resistor 52 suppresses an increase in the charging current In and suppresses an inrush current from being generated in the input current In.

In addition, since the power supply device 60 suppresses the increase in the charging current Ic when the bypass switch 54 is turned on by the magnetic bias coil 20, it is possible to suppress the inrush current from being generated in the input current In.

Furthermore, since the power supply device 60 includes the PFC circuit 62, the phase of the AC voltage Vac and the input current In can be matched, so that the power use efficiency can be improved.

In the power supply device 60, the power supply from the AC power supply 36 is temporarily stopped due to a power failure such as an instantaneous power failure, whereby the capacitor 18 is discharged. The power supply 60 starts charging the capacitor 18 when the power failure is restored. In the power supply device 60, when the bypass switch 54 is turned on at the time of recovery from the power failure, the charging current Ic of the capacitor 18 increases rapidly.

At this time, the power supply device 60 can suppress the charging current Ic from rapidly increasing to the capacitor 18 by providing the magnetically biased coil 20 connected in series with the capacitor 18. Thereby, the power supply device 60 can suppress an inrush current from being generated in the input current In when the power failure is restored.

In the above, although the aspect which aims at current suppression to a power supply device was demonstrated, application of the technique of an indication is not restricted to this. FIG. 14 shows another aspect of the disclosed technology. FIG. 14 shows a semiconductor circuit 72 and a power supply substrate 74 that supplies a DC voltage for operation to the semiconductor circuit 72. The semiconductor circuit 72 includes a pair of

power supply terminals

76A and 76B. The power supply board 74 includes a pair of

output terminals

78A and 78B. The power supply board 74 supplies a DC voltage for operation to the semiconductor circuit 72 by connecting the

power supply terminals

76A and 76B of the semiconductor circuit 72 to the pair of

output terminals

78A and 78B.

The capacitor 18 and the magnetic bias coil 20 are connected in series to the semiconductor circuit 72 in the disclosed technology. At this time, the bias coil 20 has one end connected to the + side power supply terminal 76 A and the other end connected to the + side of the capacitor 18. The capacitor 18 is connected to the power terminal 76B on the negative side.

When the power supply board 74 is in an active state capable of outputting a DC voltage, when the

semiconductor circuits

76A and 76B are connected to the

output terminals

78A and 78B, power for operation is supplied to the semiconductor circuit 72 from the power supply board 74. The

When the semiconductor circuit 72 is connected to the active power supply substrate 74, immediately after the connection, the capacitor 18 starts to be charged, and the charging current Ic rapidly increases. As a result, an inrush current flows through the power supply substrate 74. At this time, in the semiconductor circuit 72 having the magnetically biased coil 20 connected in series to the capacitor 18, the magnetically biased coil 20 suppresses the rapid increase and the peak current of the charging current Ic.

Therefore, the power supply board 74 connected to the semiconductor circuit 72 can suppress the occurrence of an inrush current due to a sudden rise in the charging current Ic, and prevent the overcurrent protection function from being activated due to the occurrence of the inrush current. Is done.

In the disclosed technique, not only the semiconductor circuit but also a DC power supply that outputs a DC voltage, such as the power supply board 74, is connected to a DC voltage supplied from the DC power supply, and a load circuit formed therein is activated. Including application to various load circuit boards.

In the disclosed technology, by applying to a power storage member such as a capacitor to which a DC voltage is applied, it is possible to suppress an increase in charging current that occurs at the start of charging of the power storage member and a maximum value of the charging current. Therefore, the occurrence of an inrush current due to an increase in charging current is suppressed.

The disclosed technology is not limited to the above-described embodiment, and any form may be used as long as each part includes a target function. In addition, all patent applications and technical documents disclosed in the patent application described in this specification include cases where individual documents, patent applications, and technical standards are specifically and individually described to be incorporated by reference. To the same extent, it is incorporated herein by reference.

Claims

A capacitor for accumulating charge by a charging current according to the applied DC voltage;
A coil connected in series to the capacitor; a core around which the coil is wound; and a magnetizing member that forms a magnetic field having a saturation magnetic flux density inside the core in the core, wherein the charging current flowing through the coil is predetermined. A magnetized coil whose inductance increases by becoming more than the value,
Including a current suppression circuit.
The current suppression circuit according to claim 1, wherein the capacitor is connected in parallel with a load to which the DC voltage is applied.
3. The current suppression circuit according to claim 2, wherein the magnetic bias coil and the capacitor are connected in parallel to the load.
A rectifying circuit that rectifies the AC voltage and generates a DC voltage to be supplied to the load;
A capacitor to which a DC voltage output from the rectifier circuit is applied;
A coil connected in series to the capacitor; a core around which the coil is wound; and a magnetizing member that forms a magnetic field having a saturation magnetic flux density inside the core in the core, wherein the charging current flowing through the coil is predetermined. A magnetized coil whose inductance increases by becoming more than the value,
Including power supply circuit.
The power supply circuit according to claim 4, wherein the load is connected in parallel to the capacitor.
6. The power supply circuit according to claim 5, wherein the load is connected in parallel to the magnetic bias coil and the capacitor.
A voltage source for supplying a DC voltage to the load;
A capacitor to which a DC voltage output from the voltage source is applied;
A coil connected in series to the capacitor; a core around which the coil is wound; and a magnetizing member that forms a magnetic field having a saturation magnetic flux density inside the core in the core, wherein the charging current flowing through the coil is predetermined. A magnetized coil whose inductance increases by becoming more than the value,
Including power supply.
The power supply device according to claim 7, wherein the capacitor is connected in parallel with the load.
The power supply device according to claim 8, wherein the magnetic bias coil and the capacitor are connected in parallel to the load.
The power supply apparatus according to claim 9, wherein the voltage source includes a rectifier circuit that rectifies an AC voltage input from an AC voltage source.
A current suppressing member that suppresses the current of the rectified voltage output from the rectifier circuit when the input of the AC voltage is started from the AC voltage source;
A voltage detection unit that detects a voltage that is output to the load while the current is suppressed by the current suppression member;
When the detection voltage of the voltage detection unit reaches a predetermined voltage, a bypass unit that bypasses the current suppression member and outputs the rectified voltage;
The power supply device according to claim 10, comprising:
A pair of terminals for receiving a DC voltage from an external power source;
A capacitor that accumulates electric charge by a charging current corresponding to an increase in the DC voltage applied between the pair of terminals;
A coil connected in series to the capacitor and connected between the pair of terminals; a core around which the coil is wound; and a magnetizing member that forms a magnetic field in the core with a saturation magnetic flux density inside the core. A magnetically biased coil whose inductance increases when the flowing charging current becomes a predetermined value or more,
A semiconductor circuit including:
A pair of terminals for receiving a DC voltage from an external power source;
A capacitor that accumulates electric charge by a charging current corresponding to an increase in the DC voltage applied between the pair of terminals;
A coil connected in series to the capacitor and connected between the pair of terminals; a core around which the coil is wound; and a magnetizing member that forms a magnetic field in the core with a saturation magnetic flux density inside the core. A magnetically biased coil whose inductance increases when the flowing charging current becomes a predetermined value or more,
Including load circuit board.