JP4487803B2 - Uninterruptible power supply and processing equipment - Google Patents

Description

  The present invention relates to an uninterruptible power supply that supplies power to a power supply target and a processing apparatus including the same.

  An uninterruptible power supply is built into various electronic devices such as a portable video playback device, and even when an AC power supply (AC power supply) such as a commercial AC power supply that is normally used is cut off or the voltage drops due to a power failure, It is a device that can be supplied with power from a direct current power source (DC power source) such as a battery as a reserve power source.

  FIG. 7 is a block diagram showing a configuration example of a conventional uninterruptible power supply. As shown in FIG. 7, in the wireless power supply device, AC power output from the commercial AC power supply 102 is rectified to DC power by the rectifier circuit 104 and then converted into a pulse signal by the converter 106. Further, pulse-like signals are output from the two output terminals OUTA and OUTB of the converter 106 to the power supply line 112 and the control bus 114, respectively, and the diodes 109a and b and the capacitors 110a and b installed in the power supply line 112 and the control bus 114, respectively. Is smoothed by a smoothing circuit 108 and converted to DC power. Here, the power supply line 112 is a power supply path through which a large current for power supply can flow, and the control bus 114 is a detection path through which a small current for detecting the oscillation state of the converter 106 flows. is there.

  The DC power (C) of the feed line 112 is input to the AC / DC switching circuit 116, while the DC power from the DC power source 120 is also input to the AC / DC switching circuit 116. The control bus 114 is provided with an oscillation state detector 118 that detects the oscillation state of the DC voltage (D) from the converter 106. The oscillation state detector 118 selects the DC power (A) from the converter 116 when the level of the DC voltage output from the converter 106 to the control bus 114 is equal to or higher than the threshold value, and vice versa. , DC power (B) from the DC power source 120 is selected. The oscillation state detector 118 supplies the AC / DC switching circuit 116 with a rectangular-wave power selection signal (for example, when the AC power source 102 is selected; high level, when the DC power source 120 is selected; low level) indicating the selection result. Output.

  The switching unit 116a of the AC / DC switching circuit 116 switches the switch for connecting the AC power source 102 or the DC power source 120 based on the power source selection signal input from the oscillation state detector 118, and the AC power source 102 or the DC power source. One of the DC powers 120 is output to the DC / DC converter 122. As a result, the DC / DC converter 122 converts the input DC power into a predetermined voltage and supplies it to the external power supply target 124.

JP-A-5-137277 Japanese Patent Laid-Open No. 9-180075

  However, in the uninterruptible power supply having the configuration shown in FIG. 7 described above, as shown below, due to the presence of the capacitors 110a and 110b of the smoothing circuit 108, a delay period is caused when switching from the AC power supply 102 to the DC power supply 120. There was a problem that the power supply temporarily stopped.

  FIG. 8 is a waveform diagram showing output voltages at points OUTA, OUTB, D, E, and F in the uninterruptible power supply of FIG. FIG. 8 shows an example in which the converter 106 is a converter (converter with an energy saving function) capable of executing an intermittent oscillation mode in which the voltage is intermittently oscillated when the power consumption of the power supply target 124 decreases.

  As shown in FIG. 8A, when the power supply from the AC power source 102 is stopped due to disconnection of the AC cord or the like, the output of the converter 106 is discharged from a capacitor (not shown) included in the rectifier circuit 104. It gradually decreases (T1 period) and then becomes zero (T2 period). However, when the DC power source 120 is selected by the switching operation of the power source (period T3), the load of the output OUTA of the converter 106 becomes no load, so that the input of the converter 106 is restored and the pulsed voltage is applied to the converter 106. Output from OUTA and shift to intermittent oscillation mode.

  Further, the capacitor 110b that smoothes the output OUTB of the converter 106 is set to a capacity that does not cause the DC voltage (D) to drop out so that the switching operation of the power source does not malfunction during the period extended in the intermittent oscillation mode.

  However, at the moment when the power supply from the AC power supply 102 is stopped, as shown in FIG. 8B, a voltage drop occurs in the smoothed DC voltage (D), and the threshold voltage value of the oscillation state detector 118 is detected. (T3 period). For this reason, as shown in FIG. 8C, the power supply selection signal of the oscillation state detector 118 changes from a high level indicating the selection state of the AC power supply 120 to a low level indicating the selection state of the DC power supply 120 (T3). period). Thereafter, when the converter 106 input is restored as described above, the DC voltage (D) rises and exceeds the return voltage value as shown in FIG. 8B. As shown, the DC power source 120 is switched to the AC power source 102 (T4 period). However, when the restart of the DC / DC converter 122 is completed and a load is applied to the output OUTA of the converter 106, a voltage drop occurs again in the DC voltage (D), so that the AC power source 102 is switched to the DC power source 120 again. . Thereafter, the switching operation between AC and DC as described above is repeated several times, and when the capacitor capacity of the rectifier circuit 104 is exhausted, it is completely switched to the DC power source 120 (period T5).

  As described above, in the configuration in which the oscillation state detector 118 detects the output OUTB of the converter 106 at the point D of the control bus 114 and switches the power supply, the delay period is inevitably caused by the action of the capacitor 110b that smoothes the output OUTB of the converter 106. (T2 period) occurs. For this reason, switching from the AC power source 102 to the DC power source 120 is delayed due to the occurrence of the delay, and as shown in FIG. 8D, the output of the DC / DC converter 122 is scratched (power failure period). There was a problem that.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a novel power supply that can stably supply power by switching between an AC power source and a DC power source without delay. Another object of the present invention is to provide an improved uninterruptible power supply and a processing apparatus equipped with the same.

In order to solve the above problems, according to one aspect of the present invention, there is provided an uninterruptible power supply that supplies power from a DC power supply instead of the AC power supply when power supplied from an external AC power supply is reduced: A rectifier circuit that rectifies AC power supplied from the AC power source into DC power, and a converter that converts the DC power output from the rectifier circuit into a pulsed signal and outputs it from the first power supply line and the control bus A first smoothing circuit provided in the first power supply line for smoothing an output voltage of the converter in the first power supply line, and an output of the converter in the control bus provided in the control bus and a second smoothing circuit for smoothing the voltage converting means and; said first smoothed by the first smoothing circuit is output from the converter of the converter The smoothed by the output from the converter of the converter means second smoothing circuit; a first output voltage at the collector line voltage detecting means and for detecting whether a first threshold value or more the second output voltage in the control bus is based on whether or not the second threshold value or more, the oscillation state detecting means for oscillating state of said converter to detect whether or not normal; said first power supply The AC power supply is selected when the first output voltage on the line is greater than or equal to the first threshold and the second output voltage on the control bus is greater than or equal to the second threshold. , When the first output voltage on the first power supply line is less than the first threshold value, or when the second output voltage on the control bus is less than the second threshold value. , the DC power supply Selection means for selecting; based on the selection result of the selecting means, the first output power input through the first feed line from said converting means, are inputted from the DC power source through a second feed line An uninterruptible power supply comprising: switching means for switching output power to be supplied to a power supply target.

  With this configuration, the voltage drop can be detected quickly by directly detecting the output voltage of the conversion means, so that the voltage can be quickly switched to the DC power supply without delay when the voltage of the AC power supply drops. Further, by detecting the oscillation state of the conversion means, it is possible to quickly switch to the DC power supply without delay even when the conversion means stops oscillating or when the oscillation frequency decreases.

  The voltage detecting means may detect whether or not the output voltage of the converting means is greater than a predetermined voltage, and the oscillation state detecting means may detect the presence or absence of oscillation from the converting means. Further, the selecting means selects an AC power source when the output voltage of the converting means is larger than a predetermined voltage and the converting means is oscillated, and when the output voltage of the converting means is equal to or lower than the predetermined voltage, or A DC power supply may be selected when there is no oscillation from the conversion means.

  The selection means may maintain the selected state of the DC power source for a predetermined period after selecting the DC power source instead of the AC power source. As a result, it is possible to prevent the AC power source from being switched to the AC power source immediately after switching to the DC power source, thereby preventing malfunctions that frequently switch between the AC power source and the DC power source.

  In addition, the selection means selects whether to supply power from an AC power supply or a DC power supply based on detection results by the voltage detection means and the oscillation state detection means, and selects a state in which the AC power supply is selected or a DC power supply. A determination circuit for outputting a power supply selection signal representing a state; a delay circuit for delaying a timing at which the power supply selection signal is input from the determination circuit and the power supply selection signal changes from a state in which a DC power supply is selected to a state in which an AC power supply is selected; May be included.

  The delay circuit may include an integration circuit or a digital circuit.

  The voltage detecting means and the oscillation state detecting means may be constituted by a comparator IC, and the selecting means may be constituted by a gate element. Thereby, the apparatus configuration can be made small and inexpensive.

  The conversion means may include a converter capable of executing an intermittent oscillation mode in which voltage oscillation is intermittently performed when power consumption of a power supply target is reduced.

  In order to solve the above problems, according to another aspect of the present invention, there is provided a processing apparatus comprising a data processing means for processing video / audio data and an uninterruptible power supply for supplying power to the data processing means. Provided. The uninterruptible power supply in this processing apparatus includes: conversion means for converting AC power supplied from an AC power source into DC power; output; voltage detection means for detecting the output voltage of the conversion means; and oscillation state of the conversion means. An oscillation state detection means for detecting; a selection means for selecting whether to supply power from an AC power supply or a DC power supply based on detection results by the voltage detection means and the oscillation state detection means; and based on a selection result by the selection means Switching means for switching the output power of the conversion means and the output power of the DC power supply and supplying the output power to the data processing means.

  As described above, according to the present invention, it is possible to provide an uninterruptible power supply apparatus that can switch between an AC power source and a DC power source without delay and can stably supply power without an interruption.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
The uninterruptible power supply according to the first embodiment of the present invention will be described in detail below. The uninterruptible power supply according to the present embodiment is a power supply apparatus that can supply power by switching between power supplied from an AC power supply (AC power supply) such as a commercial AC power supply and power supplied from another DC power supply (DC power supply). is there. This uninterruptible power supply presupposes that the power supply from the AC power supply is given priority, detects the power supply state from the AC power supply in real time, and when the power supply from the AC power supply drops (for example, power failure, AC This is a switching type power supply device having a function of switching to the power of the DC power source when the AC power source is cut off due to the disconnection of the cord.

  Such an uninterruptible power supply device is an information processing device such as a portable video / audio player, a PDA (Personal Digital Assistant), a portable terminal such as a cellular phone, or a personal computer (notebook type or desktop type). It can be applied to various electronic devices (processing devices) such as various home appliances such as home game machines, television receivers, DVD recorders / players and the like. In the following description, an example in which the uninterruptible power supply according to the present embodiment is applied to a portable video processing device will be described, but the present invention is not limited to such an example.

  First, a schematic configuration of a portable video processing apparatus 1 to which the uninterruptible power supply 10 according to the present embodiment is applied will be described with reference to FIG. FIG. 1 is a schematic configuration diagram showing a portable video processing device 1 to which the uninterruptible power supply 10 according to the present embodiment is applied.

  As shown in FIG. 1, a portable video processing device 1 is a small video and audio player that can be carried by a user. The video processing apparatus 1 includes a video processing unit 9 that processes video and audio data, and an uninterruptible power supply 10.

  The video processing unit 9 corresponds to data processing means according to the present embodiment, and reads and reproduces video and audio data from a storage medium such as an optical disk, a semiconductor memory, or a hard disk. The video processing unit 9 includes, for example, a disk drive, a decoder, a playback device, video playback software installed in the video processing device 1, and the like. The video processing unit 9 may be configured to execute various processes (for example, recording, editing, deletion, ripping, self-recording, transfer to a PC, etc.) other than playback for video / audio data.

  The uninterruptible power supply 10 includes, for example, various circuits built in the video processing device 1 and supplies power to each unit in the video processing device 1 such as the video processing unit 9. The uninterruptible power supply 10 is supplied with AC power (AC power) from a commercial AC power supply (AC power supply) 2 via an AC cord 3 connected to an AC input terminal of the video processing apparatus 1.

  Further, the uninterruptible power supply 10 includes a direct current power (DC power) 4 from a direct current power supply (DC power supply) 4 as a reserve power supply of the AC power supply 2 via a DC cord 5 connected to a DC input terminal of the video processing device 1. DC power) can be supplied. The DC power source 4 includes various devices capable of outputting DC power, such as an AC adapter 6 connected to a commercial AC power source 2, a DC stabilized power source, or a battery connecting device 8 as shown in FIG. The battery 7 is externally connected. For example, when the battery 7 is used as the DC power source 4, the image processing device 1 is not connected to the AC power source 2 by attaching the battery connection device 8 to one side surface of the housing of the image processing device 1. The video can be reproduced by the power supplied from the battery 7. For this reason, the user can take out the portable video processing apparatus 1 outdoors and view the video.

  As described above, the DC power supply 4 according to the present embodiment is externally attached to the video processing device 1 that is a power supply target as described above. However, the present invention is not limited to this example. For example, the DC power source 4 including a rechargeable / non-rechargeable battery may be incorporated in a processing device such as the video processing device 1.

  The uninterruptible power supply 10 connected to the AC power supply 2 and the DC power supply 4 as described above switches between the AC power supply 2 and the DC power supply 4 and stably supplies power to the video processing unit 9 and the like without an interruption. Can do. Specifically, when the AC cord 3 is connected and the AC power from the AC power source 2 is normally supplied, the uninterruptible power supply 10 converts the AC power input from the AC power source 2 into DC power. To the video processing unit 9 and the like. On the other hand, the uninterruptible power supply 10 instantaneously switches from the AC power supply 2 to the DC power supply 4 when the AC cord 3 is disconnected, or when the AC power supply 2 is blacked out or has a voltage drop. DC power is supplied to the video processing unit 9 and the like.

  Below, based on FIG.2 and FIG.3, the uninterruptible power supply 10 concerning this embodiment is demonstrated in detail. 2 is a block diagram showing a schematic configuration of the uninterruptible power supply 10 according to the present embodiment, and FIG. 3 is a circuit diagram showing a circuit configuration of the uninterruptible power supply 10 according to the present embodiment.

  As shown in FIG. 2, the uninterruptible power supply 10 includes a conversion means 20 comprising a rectifier circuit 22, a converter 24 and smoothing circuits 26, 28, a voltage detector 30 as an example of a voltage detection means, and an oscillation state detection means. As an example, an oscillation state detector 40, a selection unit 50 including a determination circuit 52 and a delay circuit 54, a switching unit 60 including an AC / DC switching circuit 62 and a switch 64, and a DC / DC converter 70 are provided.

  The conversion means 20 is connected to the AC power source 2, converts AC power (for example, 100 V) supplied from the AC power source 2 into DC power, and switches the DC power to switch the first power supply line 12 and the control bus 14. Respectively.

  Specifically, the rectifier circuit 22 is configured by, for example, a diode bridge (not shown) composed of a plurality of diodes, and rectifies AC power supplied from the AC power source 2 into DC power, thereby converting the converter. 24.

  The converter 24 is composed of, for example, a converter IC that can execute the intermittent oscillation mode. As described above, the intermittent oscillation mode is a mode in which power is oscillated and supplied intermittently for the purpose of energy saving when the power consumption of the power supply target (the video processing unit 9 or the like) is reduced (FIG. 8 ( a)).

  The converter 24 oscillates by converting the DC power input from the rectifier circuit 22 into a pulsed signal (for example, 15 V), and outputs it from the output terminal OUTA to the switching means 60 via the first feed line 12. , Output from the output terminal OUTB to the oscillation state detector 40 via the control bus 14. The first power supply line 12 is a power supply path through which a large current can flow to supply the power output from the converter 24. The control bus 14 is a detection path through which a small current for detecting the oscillation state of the converter 106 flows. As shown in FIG. 4, the pulse-like output power oscillated from the output terminals OUTA and OUTB by the converter 24 becomes close to each other when the oscillation frequency is normal, and when the oscillation frequency decreases, the pulse power is pulsed. The distance between each other is sparse.

  The smoothing circuit 26 is provided in the middle of the first power supply line 12, and the smoothing circuit 28 is provided in the middle of the control bus 14. As shown in FIG. 3, the smoothing circuits 26 and 28 branch from the diodes D1 and D2 disposed on the first power supply line 12 and the control bus 14 and from the first power supply line 12 and the control bus 14, for example. Consists of capacitors C1 and C2 arranged on the line. One ends of the capacitors C1 and C2 are connected to the downstream side of the diodes D1 and D2 of the first power supply line 12 and the control bus 14, and the other end is grounded. In accordance with the difference in the amount of current flowing through the first power supply line 12 and the control bus 14, the capacity of the capacitor C1 of the smoothing circuit 26 (for example, 1150 μF) is larger than the capacity of the capacitor C2 of the smoothing circuit 28 (for example, 20 μF).

  The smoothing circuits 26 and 28 configured as described above smooth the output signal of the converter 24 in the first power supply line 12 and the control bus 14. As shown in FIG. 4A, for example, when the converter 24 is oscillating at a normal oscillation frequency, the smoothing circuits 26 and 28 are arranged in the form of dense pulses in the first power supply line 12 and the control bus 14. The output voltage (OUTA, OUTB) is smoothed and converted to a DC voltage having a continuous waveform equal to or higher than the threshold voltage (C point, D point). Further, as shown in FIG. 4B, when the oscillation frequency of the converter 24 is lower than the assumed frequency, the smoothing circuits 26 and 28 output sparse pulse-like outputs in the first power supply line 12 and the control bus 14. The voltage (OUTA point, OUTB) is smoothed and converted to a pulsed DC voltage with a sharp rise and a slow fall (C point, D point). During such smoothing, the voltage of the control bus 14 drops more rapidly than the voltage of the first power supply line 12 because of the difference in capacitance and discharge characteristics of the capacitors C1 and C2.

  Note that the capacitors C1 and C2 are set to have a capacitance that can be smoothed so that the waveform of the DC voltage intermittently oscillated from the converter 24 is not intermittently pulsed when the converter 24 is in the intermittent oscillation mode. Thereby, when the intermittent oscillation mode is executed, the detectors 30 and 40 do not react to the output voltage intermittently oscillated from the converter 24, so that a power supply switching operation described later can be prevented from malfunctioning.

  The voltage detector 30 is connected to a point C on the downstream side of the smoothing circuit 26 in the first feeding line 12 (feeding path). The voltage detector 30 detects whether or not the output voltage level of the converter 24 is greater than a predetermined threshold voltage value, and whether or not the output voltage of the converter 24 is acceptable (is a normal voltage level) according to the detection result. Or not) is output to the determination circuit 52 of the selection means 50. This voltage enable / disable signal is, for example, a rectangular wave signal as shown by the waveform at point E in FIG. 4, indicating that the output voltage of the converter 24 is normal when the level is low, and that of the converter 24 when the level is high. Indicates that the output voltage has dropped to an abnormal value.

  More specifically, as shown in FIG. 3, for example, the voltage detector 30 is on a line connecting the comparator U1 configured by a comparator IC or the like, and the first power supply line 12 and one input terminal of the comparator U1. And a reference power source S1 connected to the other input terminal of the comparator U1. The resistor R1 is connected to the other input terminal of the comparator U1.

  As shown in FIG. 4, the voltage detector 30 having such a configuration is configured such that the comparator U1 outputs the output voltage of the converter 24 at the point C of the first feed line 12 and a predetermined first threshold voltage value output from the reference power source S1. (For example, 9V) and detect whether or not the output voltage of the converter 24 is equal to or higher than the first threshold voltage value. As a result of the detection, if the output voltage of the converter 24 is larger than the first threshold voltage value, the voltage detector 30 determines that the output voltage level of the converter 24 in the first feed line 12 is normal, and the voltage For example, a low-level voltage enable / disable signal indicating normality is output. On the other hand, when the output voltage of the converter 24 is equal to or lower than the first threshold voltage value, the voltage detector 30 determines that the output voltage level of the converter 24 in the first power supply line 12 is abnormal, and detects the voltage abnormality. For example, a high level voltage enable / disable signal is output.

  As described above, the voltage detector 30 monitors the output voltage of the converter 24 at the point C of the first power supply line 12, and outputs a low-level voltage enable / disable signal when the output voltage is normal. When a drop is detected, a high level voltage enable / disable signal is output. That is, the voltage detector 30 inverts and outputs the rectangular wave voltage enable / disable signal output from the comparator U1 depending on whether or not the output voltage of the converter 22 is normal.

  Contrary to the above, the voltage detector 30 outputs a high level voltage enable / disable signal when the output voltage of the converter 24 is normal, and the low level when the output voltage of the converter 24 is abnormal. The voltage availability signal may be output.

  As described above, the voltage detector 30 directly detects the voltage at the point C of the first feed line 12 that is the feed line, thereby supplying the DC power supplied from the AC power source 2 and converted by the conversion means 20. Can be detected without delay.

  The oscillation state detector 40 is connected to the downstream side of the smoothing circuit 28 in the control bus 14 (detection path). The oscillation state detector 40 detects whether or not the oscillation state (for example, the oscillation frequency) of the converter 24 is normal, and according to the detection result, whether or not the oscillation state of the converter 24 is possible (the oscillation state is normal). Is output to the determination circuit 52 of the selection means 50. This oscillation state enable / disable signal is, for example, a rectangular wave signal as shown by the point F waveform in FIG. 4, indicating that the converter oscillation state is normal when the level is low, and oscillation of the converter when the level is high. Indicates that the condition is abnormal.

  Specifically, for example, as shown in FIG. 3, the oscillation state detector 40 is disposed on a comparator U2 composed of a comparator IC or the like and a control bus 14 connected to one input terminal of the comparator U2. Resistor R3, resistor R4 arranged on a line branched from the control bus 14 and grounded, and a reference power source S2 connected to the other input terminal of the comparator U2.

  As shown in FIG. 4, in the oscillation state detector 40 having such a configuration, the output voltage of the converter 24 in the control bus 14 and a predetermined second threshold voltage value (for example, 10 V) output from the reference power source S2 by the comparator U2. To detect whether or not the output voltage of the converter 24 is equal to or higher than the second threshold voltage value. As a result of this detection, when the output voltage of the converter 24 is larger than the second threshold voltage value, the oscillation state detector 40 determines that the converter 24 is oscillating and indicates, for example, a low level indicating the normal oscillation state. The oscillation state enable / disable signal is output. On the other hand, when the output voltage of the converter 24 is equal to or lower than the second threshold voltage value, the oscillation state detector 40 determines that the converter 24 is not oscillating and indicates, for example, a high level oscillation indicating an oscillation state abnormality. Outputs status enable / disable signal.

  Thus, by detecting the voltage level on the control bus 14, it is possible to detect whether or not the oscillation frequency of the converter is normal. That is, as shown in FIG. 4A, when the converter 24 outputs at a normal oscillation frequency higher than a predetermined reference oscillation frequency, the second threshold is obtained by smoothing by the smoothing circuit 28. A continuous voltage waveform larger than the voltage value (for example, 10 V) is input to the oscillation state detector 40. Therefore, during the input period of the continuous voltage waveform larger than the second threshold voltage value, the oscillation state detector 40 determines that the oscillation state is normal and indicates, for example, a low level indicating the normal oscillation state. The oscillation state enable / disable signal is output.

  On the other hand, as shown in FIG. 4B, when the converter 24 outputs at an oscillation frequency equal to or lower than a predetermined reference oscillation frequency or when the converter 24 does not oscillate, smoothing is performed by the smoothing circuit 28. Even if it is, a voltage waveform that is partially or wholly lowered to a second threshold voltage value (for example, 10 V) or less is input to the oscillation state detector 40. For this reason, during the input period of the voltage waveform below the second threshold voltage value, the oscillation state detector 40 determines that the converter 24 is not oscillating, and indicates an oscillation state abnormality, for example, a high level oscillation state. A propriety signal is output.

  As described above, when the oscillation state detector 40 monitors the oscillation frequency of the converter 24 and determines that it is oscillating at a normal frequency higher than the predetermined reference oscillation frequency, the oscillation state detector 40 outputs a low level oscillation state enable / disable signal. On the other hand, when the oscillation of the converter 24 is stopped or when it is determined that the converter 24 has fallen below a predetermined frequency, a high-level oscillation state enable / disable signal is output. That is, the oscillation state detector 40 inverts and outputs the rectangular wave oscillation state propriety signal output from the comparator U2 depending on whether or not the oscillation state of the converter 22 is normal.

  In contrast to the above, the oscillation state detector 40 outputs a high-level oscillation state enable / disable signal when the oscillation state of the converter 24 is normal, and when the oscillation state of the converter 24 is abnormal, A low level oscillation state enable / disable signal may be output.

  The selection means 50 selects whether power is supplied from the AC power source 2 or the DC power source 4 based on the detection results by the voltage detector 30 and the oscillation state detector 40. This selection means 50 generates and outputs a power source selection signal based on the voltage enable / disable signal and the oscillation enable / disable signal input from the voltage detector 30 and the oscillation state detector 40, and is input from the determination circuit 52. The delay circuit 54 delays the change timing of the power supply selection signal.

  As shown in FIG. 3, the determination circuit 52 is composed of a logic circuit such as a NOR circuit. The determination circuit 52 is based on the voltage availability signal (FIG. 5A) input from the voltage detector 30 and the oscillation status availability signal input from the oscillation state detector 40 (FIG. 5B). Thus, it is selected whether the power is supplied from the AC power source 2 or the DC power source 4, and a power source selection signal (FIG. 5C) indicating the selection state of the AC power source 2 or the DC power source 4 is generated and output. The power supply selection signal is, for example, a high-level and low-level rectangular wave signal. When the power source selection signal is at a high level, the AC power source 2 is selected. On the other hand, when the power source selection signal is at a low level, the DC power source 4 is selected.

  As shown in FIGS. 5A to 5C, when the input voltage enable / disable signal is at a low level indicating normal voltage and the input oscillation state enable / disable signal is at a low level indicating normal oscillation state In addition, a high-level power source selection signal indicating a state in which the AC power source 2 is selected is output. On the other hand, when the input voltage enable / disable signal is at a high level indicating an abnormal voltage, or when the input oscillation state enable / disable signal is at a high level indicating an abnormal oscillation state, the determination circuit 52 is connected to the DC power source 4. A low-level power source selection signal indicating the state in which is selected is output.

  As described above, the determination circuit 52 selects the AC power source 2 as the power supply source when the detection result of the voltage detector 30 indicates normal voltage and the detection result of the oscillation state detector 40 indicates normal oscillation state. In other cases, the DC power source 4 is selected as the power supply source.

  The delay circuit 54 is a circuit that delays a part of the power supply selection signal in order to maintain the selected state of the DC power supply 4 for a predetermined period after the DC power supply 4 is selected instead of the AC power supply 2. For example, as shown in FIG. 3, the delay circuit 54 includes a comparator U3 composed of a comparator IC and the like, a resistor R5 arranged on a line connecting the determination circuit 52 and one input terminal of the comparator U3, Capacitor C3 arranged on a line branched from the line and grounded, and a pull-up resistor arranged on another line branched from the line and connected to an arbitrary DC power supply (for example, DC power supply 4) R6, a pull-up resistor R7 arranged on a line branched from the line and grounded, and a reference power source S3 connected to the other input terminal of the comparator U3. Thus, the delay circuit 54 according to the present embodiment has a circuit configuration using an integrating circuit, and the delay time is determined by the time constants of the resistor R5 and the capacitor C3.

  As shown in FIGS. 5C to 5E, the delay circuit 54 having such a configuration changes from the selection state of the DC power source 4 to the selection state of the AC power source 2 in the power source selection signal input from the determination circuit 52. Delay timing. Specifically, when the power supply selection signal input to the delay circuit 54 changes from the DC selection state (low level) to the AC selection state (high level), the grounded capacitor C3 is charged, so that it is input. As shown in FIG. 5D, the rectangular-wave power supply selection signal is converted into a waveform having a gradual rise at the time of change from the DC power supply selection state to the AC power supply selection state (rise is gradual). Further, the power supply selection signal converted into a waveform having a gradual rise as described above is input to the comparator U3 and, as shown in FIG. 5E, is equal to or higher than a predetermined third threshold voltage value of the reference power supply S3. In this case, the waveform is converted into a rectangular waveform having a high level and a low level when the voltage is lower than the third threshold voltage value.

  On the other hand, the delay circuit 54 hardly delays the timing at which the power supply selection signal changes from the selection state (high level) of the AC power supply 2 to the selection state (low level) of the DC power supply 4 (falling is almost instantaneous). . As a result, when the voltage of the AC power source 2 drops, switching from the AC power source 2 to the DC power source 4 can be performed instantaneously.

  As described above, the delay circuit 54 delays only the change timing from the selection state of the DC power source 4 to the selection state of the AC power source 2 in the power source selection signal for a predetermined period. This delay time is set to a time (for example, about several seconds) that does not frequently cause AC-DC power supply switching in a short time by adjusting the time constant of the resistor R5 and the capacitor C3 of the delay circuit 54. . By providing such a delay circuit 54, the AC power source 2 is not switched for a predetermined period after the DC power source 4 is once switched. This prevents frequent switching of the AC-DC power supply during the intermittent oscillation mode of the converter 24 as shown in FIGS. 8C to 8D, thereby preventing excessive switching operation. And stable power supply.

  In order to delay only a part (rise) of the power supply selection signal as described above, the delay circuit 54 is connected to the output side of the comparator U3 and the capacitor C3 instead of the pull-down resistor R7, for example. A discharge reset circuit (not shown) for discharging the capacitor C3 based on the output of U3 (point I) may be provided. The discharge reset circuit includes a transistor (not shown) connected in parallel to the capacitor C3, and discharges the capacitor C3 when the power supply selection signal (point I) output from the comparator U3 becomes high level. . This prevents the power supply selection signal (point H) from instantaneously falling from the high level to the low level, thereby preventing the delay until the switching timing from the AC power supply 2 to the DC power supply 4. Further, the delay circuit 54 as described above is not necessarily provided.

  The switching unit 60 switches between the output power (AC power) of the conversion unit 20 and the output power (DC power) of the DC power source 4 based on the power source selection signal input from the delay circuit 54 of the selection unit 50, and DC / Output to DC converter 70. The switching means 60 includes an AC / DC switching circuit 62 and a switch 64 as shown in FIG.

  As shown in FIG. 3, the switch 64 includes a first switch 64 a disposed in the first power supply line 12 connected to the converter 24 and a second switch 16 disposed in the second power supply line 16 connected to the DC power source 4. 2 switches 64b. The first switch 64 a is configured by a gate element such as a field effect transistor (FET), for example, and is a switch that connects / disconnects the first power feed line 12 that connects the converter 24 and the DC / DC converter 70. The second switch 64b is a switch that is configured by, for example, a gate element such as an FET, and connects / disconnects the second power supply line 16 that connects the DC power supply 4 and the DC / DC converter 70. The first and second switches 64a and 64b are turned on when, for example, a low-level power supply selection signal is input, the power supply lines 12 and 16 are connected, and a high-level power supply selection signal is input. And the power supply lines 12 and 16 are shut off.

  Further, as shown in FIG. 3, the AC / DC switching circuit 62 includes a first driver 62a for turning on / off the first switch 64a and a second driver 62b for turning on / off the second switch 64b. . As shown in FIG. 5F, the first driver 62a inverts the power source selection signal input from the delay circuit 54 of the selection means 50 and outputs the inverted signal to the first switch 64a. On the other hand, as shown in FIG. 5G, the second driver 62b outputs the power source selection signal input from the delay circuit 54 of the selection means 50 to the second switch 64b without being inverted.

  When the high-level power supply selection signal (point I) indicating the selection state of the AC power supply 2 is input from the selection means 50, the switching means 60 having such a configuration turns on the first switch 64a and the second switch 64b. Is turned off, DC power supplied from the AC power source 2 via the converter 24 is output to the DC / DC converter 70. On the other hand, when a low-level power source selection signal (point I) indicating the selection state of the AC power source 2 is input from the selection unit 50, the first switch 64a is turned off and the second switch 64b is turned on. DC power of the DC power supply 4 is output to the DC / DC converter 70.

  The DC / DC converter 70 reduces the DC power input from the switching means 60 to a predetermined voltage and supplies it to an external power supply target (the video processing unit 9 or the like).

  The uninterruptible power supply 10 according to the present embodiment has been described in detail above. In such an uninterruptible power supply 10, the voltage detector 30 directly detects a voltage drop in the first power supply line 12 that is a power supply path of the AC power supply 2, so that the AC power supply 2 and the DC power supply 4 are delayed. It can be switched without.

  Specifically, the output voltage of the converter 24 falls below the target output power of the DC / DC converter 70 even when the output of the AC power supply 2 drops due to a power failure or the AC cord 3 being disconnected. Before that, the DC power source 4 can be quickly switched. By switching between the AC power supply 2 and the DC power supply 4 in this way, the voltage input to the DC / DC converter 70 is always the target output voltage of the DC / DC converter 70 as shown in FIG. The voltage becomes larger than that. Therefore, unlike the conventional power supply device shown in FIG. 8, there is no switching delay such as switching to the DC power supply 120 after the output voltage of the converter 106 drops below the target output voltage of the DC / DC converter 122. Therefore, in the uninterruptible power supply 10 according to the present embodiment, the output voltage of the DC / DC converter 70 does not drop below the target voltage, so that the video processing unit 9 or the like that is the power supply target continues to operate favorably. Can do.

  Further, the voltage detector 30 and the oscillation state detector 40 can simultaneously detect the output voltage of the converter 24 and whether or not the oscillation state is possible. Therefore, even if the output of the converter 24 suddenly drops and then recovers or gradually drops, it is accurately detected that an abnormality has occurred in the AC power source 2 and the DC power source 4 is detected. It can be switched appropriately.

  In addition, by providing the delay circuit 54, the change timing of the power source selection signal from the DC selection state to the AC selection state can be delayed. For this reason, once the AC power supply 2 is switched to the DC power supply 4, the switching means 60 can be prevented from performing the switching operation during a predetermined period delayed by the delay circuit 54. Therefore, as shown in FIG. 8, it is possible to prevent an unnecessary switching operation such that the AC power source 102 and the DC power source 120 are frequently switched alternately and repeatedly, thereby stably supplying power. Further, since the delay circuit 54 does not delay the change timing from the selection state of the AC power source 2 to the selection state of the DC power source 4 in the power source selection signal, the switching to the DC power source 4 is instantaneously performed when the voltage of the AC power source 2 drops. Is possible.

  Even in the case where the delay circuit 54 is not provided, the low-voltage power supply 10 can realize power supply without an uninterruptible power supply. Specifically, as shown in FIG. 6B, the switching operation between the AC power source 2 and the DC power source 4 increases, and the input voltage to the DC / DC converter 70 at the time of switching is the DC / DC converter. Since it is larger than the target output voltage of 70, there is no problem in power supply.

  The uninterruptible power supply 10 can be configured using small general-purpose parts such as resistors, capacitors, gate elements such as transistors, and IC parts such as comparator ICs without using large parts such as relay circuits. The configuration can be made small and inexpensive.

  Further, since the voltage level and the oscillation state are detected on the secondary side downstream from the converter 24, safety standards (for example, UL ( Underwriters' Laboratories Inc.), IEC (International Electrotechnical Commission), etc.). For this reason, it is easy to select components, and the board area can be reduced.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, in the above embodiment, the DC power supply 4 is externally attached to the uninterruptible power supply 10, but the present invention is not limited to such an example, and the DC power supply 4 is configured by a battery or the like to the uninterruptible power supply 10. It may be built in.

  The power supply target of the low power supply apparatus 10 is not limited to the example of the video processing unit 9 of the video processing apparatus 1 as in the above embodiment, but is a personal computer, a portable audio player, a stationary video / audio. In various processing devices such as a player, any data processing means for processing various data such as video data, audio data, text data, and control data may be used.

  In the above embodiment, the converter 24 that executes the intermittent oscillation mode is used. However, the present invention is not limited to this example, and a converter that does not execute the intermittent oscillation mode may be used.

  In addition, the high level and low level of the voltage enable / disable signal, oscillation state enable / disable signal, and power supply selection signal may be inverted to represent a state opposite to the above embodiment. Each of these signals is not limited to the example of the rectangular wave signal as in the above embodiment, and any form of signal can be used as long as the signals can express two different states.

  In the delay circuit 54 according to the above embodiment, the power source selection signal is delayed using the integration circuit. However, the present invention is not limited to this example, and the specific configuration of the delay circuit 54 can be arbitrarily changed in design. is there. For example, the delay circuit 54 may be a digital circuit (counter, clock frequency divider, etc.), which allows accurate delay and facilitates circuit modification.

  The present invention can be applied to an uninterruptible power supply, and in particular, can be applied to an uninterruptible power supply that can stably supply power to various electronic devices.

1 is a schematic configuration diagram showing a portable video processing device to which an uninterruptible power supply device according to a first embodiment of the present invention is applied. It is a block diagram which shows schematic structure of the uninterruptible power supply device concerning the embodiment. It is a circuit diagram which shows the circuit structure of the uninterruptible power supply device concerning the embodiment. It is a wave form diagram which shows the voltage waveform in each point of the uninterruptible power supply concerning the embodiment. It is a wave form diagram which shows the voltage waveform in each point of the uninterruptible power supply concerning the embodiment. It is a wave form diagram which shows the input voltage with respect to the DC / DC converter of the uninterruptible power supply concerning the embodiment. It is a block diagram which shows schematic structure of the conventional uninterruptible power supply. It is a wave form diagram which shows the voltage waveform of each point in the conventional uninterruptible power supply.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Portable video processing apparatus 2 AC power supply 4 DC power supply 9 Video processing part 10 Uninterruptible power supply apparatus 12 1st electric power feeding line 14 Control bus 16 2nd electric power feeding line 20 Conversion means 22 Rectifier circuit 24 Converter 30 Voltage detector 40 Oscillation state Detector 50 Selection means 52 Judgment circuit 54 Delay circuit 60 Switching means 62 AC / DC switching circuit 64 Switch 70 DC / DC converter

Claims (7)

An uninterruptible power supply that supplies power from a DC power supply instead of the AC power supply when the power supplied from an external AC power supply decreases:
A rectifier circuit that rectifies AC power supplied from the AC power source into DC power, and a converter that converts the DC power output from the rectifier circuit into a pulsed signal and outputs it from the first power supply line and the control bus A first smoothing circuit provided in the first power supply line for smoothing an output voltage of the converter in the first power supply line, and an output of the converter in the control bus provided in the control bus Conversion means comprising a second smoothing circuit for smoothing the voltage ;
Voltage detection for detecting whether or not a first output voltage in the first power supply line output from the converter of the conversion means and smoothed by the first smoothing circuit is equal to or higher than a first threshold value. Means;
Based on whether the second output voltage in the control bus output from the converter of the conversion means and smoothed by the second smoothing circuit is equal to or higher than a second threshold value, the oscillation of the converter Oscillation state detecting means for detecting whether or not the state is normal ;
When the first output voltage in the first power supply line is greater than or equal to the first threshold and the second output voltage in the control bus is greater than or equal to the second threshold; When an AC power source is selected and the first output voltage in the first power supply line is less than the first threshold value, or the second output voltage in the control bus is the second threshold value. If it is less than, and selecting means for selecting the DC power supply;
Based on the selection result by the selection means, the first output power input from the conversion means through the first power supply line and the output power input from the DC power supply through the second power supply line are switched. Switching means for supplying power to the power supply target;
An uninterruptible power supply. The selection means includes
The uninterruptible power supply according to claim 1, wherein the state in which the DC power source is selected is maintained for a predetermined period after the DC power source is selected instead of the AC power source. The selection means includes
Based on detection results by the voltage detection means and the oscillation state detection means, the power supply is selected from the AC power supply or the DC power supply, and the AC power supply is selected or the DC power supply is selected. A determination circuit for outputting a power supply selection signal representing
A delay circuit for delaying a timing at which the power source selection signal is input from the determination circuit and the power source selection signal changes from a state where the DC power source is selected to a state where the AC power source is selected;
The uninterruptible power supply device according to claim 2, comprising:   The uninterruptible power supply according to claim 3, wherein the delay circuit includes an integration circuit or a digital circuit. The voltage detection means and the oscillation state detection means are constituted by a comparator IC,
The uninterruptible power supply according to claim 1, wherein the selection unit includes a gate element. Wherein said converter converting means, wherein a viable converter intermittent oscillation mode of performing intermittently the voltage oscillation at the power consumption reduction of supplied power, the uninterruptible power supply of claim 1. A processing device comprising data processing means for processing video / audio data and an uninterruptible power supply for supplying power to the data processing means:
The uninterruptible power supply is
A rectifier circuit that rectifies AC power supplied from an AC power source into DC power; a converter that converts the DC power output from the rectifier circuit into a pulsed signal and outputs the signal from the first power supply line and the control bus; , A first smoothing circuit provided in the first power supply line for smoothing an output voltage of the converter in the first power supply line, and an output voltage of the converter in the control bus provided in the control bus Conversion means comprising a second smoothing circuit for smoothing ;
Voltage detection for detecting whether or not a first output voltage in the first power supply line output from the converter of the conversion means and smoothed by the first smoothing circuit is equal to or higher than a first threshold value. Means;
Based on whether the second output voltage in the control bus output from the converter of the conversion means and smoothed by the second smoothing circuit is equal to or higher than a second threshold value, the oscillation of the converter Oscillation state detecting means for detecting whether or not the state is normal ;
When the first output voltage in the first power supply line is greater than or equal to the first threshold and the second output voltage in the control bus is greater than or equal to the second threshold; When an AC power source is selected and the first output voltage in the first power supply line is less than the first threshold value, or the second output voltage in the control bus is the second threshold value. If it is less than, and selecting means for selecting the DC power supply;
Based on the selection result by the selection means, the first output power input from the conversion means through the first power supply line and the output power input from the DC power supply through the second power supply line are switched. Switching means for supplying power to the power supply target;
A processing device comprising:

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