WO2006051843A1

WO2006051843A1 - Power supply apparatus

Info

Publication number: WO2006051843A1
Application number: PCT/JP2005/020591
Authority: WO
Inventors: Shinji Kudo
Original assignee: Shinji Kudo
Priority date: 2004-11-12
Filing date: 2005-11-10
Publication date: 2006-05-18
Also published as: TW200627751A; JPWO2006051843A1

Abstract

A power supply apparatus for supplying power to a computer device or the like, wherein in case of power failure, a sufficient amount of power can be supplied, the structure is simple and an excellent cost-effectiveness is achieved. The power supply apparatus comprises a rectifier (2) for rectifying an AC voltage supplied from an AC power supply source; a voltage stabilizing circuit in which a smoothing capacitor (4) connected to the rectifier is further connected in parallel to a voltage holding capacitor (6), which has a larger capacitance than the smoothing capacitor, via a resistor (8); a voltage converting circuit (14) DC/DC converts an output voltage from the voltage stabilizing circuit to a lower voltage; and a power failure detecting circuit (12) for detecting a power failure of the AC power supply source.

Description

Specification

Power supply

Technical field

The present invention relates to a power supply device that supplies power to an electronic device such as a computer device.

Background art

[0002] In the event of an unexpected power failure, such as a power outage, momentary power outage, voltage drop, etc. on a computer device, etc., the computer device must be properly shut down, causing file corruption, loss, Damage may occur. On the other hand, the uninterruptible power supply shown in Fig. 13 has been developed to prevent the above power accident.

This power supply device has a full-wave rectifier 82 for supplying DC power, a smoothing capacitor 84, and a DC voltage conversion circuit 86, while a power failure detection circuit 88 and a charging circuit 90 for coping with a power failure. And a storage battery 91, a voltage conversion circuit 92, and a switching circuit 94. While this power supply device supplies DC power to the computer device, it supplies power from the storage battery 91 in the event of a power failure, and the computer device that has received the power failure status notification from the power failure detection circuit 88 performs an appropriate shutdown process.

[0004] Further, as shown in Patent Document 1, a power supply device that does not use the above storage battery has also been developed. This power supply device increases the capacity of the smoothing capacitor in the power supply circuit, and is stored in this smoothing capacitor during a power failure. It is an attempt to supply power for the time it takes for the computer device to shut down using only the charge.

[0005] On the other hand, a power failure detection circuit for detecting a power failure has also been developed. For example, a power failure detection circuit shown in FIG. 14 is generally known. In this circuit, the primary side circuit and the secondary side circuit are insulated by using a photo force bra 100. This primary circuit includes a full wave rectifier 101, a time constant circuit of a resistor 102 and a capacitor 103, a transistor 104 as a switching element, and the like. An auxiliary power source 105 is arranged in series with the photocoupler 100 to drive the transistor 104 and supply current to the light emitting diode of the photopower bra 100 when the transistor 104 is turned on. [0006] In the power failure detection circuit, the capacitor 103 is charged while the AC power is normally supplied, and the transistor 104 is turned on by this charging voltage. When the transistor 104 is turned on, the light emitting diode of the photopower bra 100 emits light and the light receiving transistor is turned on. At this time, the collector voltage of the light receiving transistor of the photocoupler 100 has dropped, and the comparison voltage applied to the terminal (+) of the comparator 106 connected to this collector is lower than the reference voltage of the terminal (-). The output of the comparator 106 is turned off.

Here, when a power failure occurs in the AC power supply, the capacitor 103 is discharged, the voltage is lowered, the transistor 104 is turned off, and the photocoupler 100 is also turned off. At this time, the output of the comparator 106 is turned on when the collector voltage of the photopower plug 100 becomes high, and a detection signal for power failure is output. In such a power failure detection circuit, the auxiliary power source 105 is indispensable for forming a circuit for confirming a power failure of the AC power source in the primary side circuit. Also, the description of the signal detecting means Yore was the photo force bra to the power supply circuit of Patent Document 2, wherein power ^s of the circuit to the power supply apparatus of Patent Document 3 for detecting the output of the secondary power supply circuit in the photo force bra is there.

Patent Document 1: Japanese Patent Application Laid-Open No. 62-277034

Patent Document 2: JP-A-9 56159

Patent Document 3: JP 2000-333385

Patent Document 4: Japanese Utility Model Publication No. 6-9346

Disclosure of the invention

Problems to be solved by the invention

[0009] Now, the life of the storage battery 91 used in the uninterruptible power supply is usually 2 to 3 years, which requires regular maintenance and monitoring. In the case of several power outage accidents in a short time, the battery is repeatedly discharged without being fully charged, so that the power supply device does not function sufficiently. In addition, the storage battery needs current to charge and to guarantee self-discharge, which causes unnecessary power loss and a charging circuit for charging. Switching between times was necessary, and the loss of the circuit and switching time was a problem. Patent Document 4 describes a circuit that supplies power from a backup power supply unit equipped with an auxiliary capacitor in the event of a power failure. The loss of switching time is also a problem for the circuit.

[0010] Further, when the power supply device using the smoothing capacitor 84 is used as a power supply for a normal computer device, the time during which the smoothing capacitor can supply power is as short as about 20 ms to 40 ms. For this reason, in order to supply power while the computer device is shut down, the capacity of the smoothing capacitor needs to be considerably increased. However, when the capacity of this smoothing capacitor is increased, a very large inrush current flows when the power is turned on, so a special inrush current prevention circuit is required. Also, since the impedance of the smoothing circuit seen from the input side of the power supply during operation is very low, a very large current flows when the power supply voltage fluctuates, causing the power supply breaker to drop or the rectifier diode to be destroyed. For example, a smoothing capacitor with a large capacity cannot be used easily.

On the other hand, in the conventional power failure detection circuit, the auxiliary power source 105 is indispensable for exerting the power failure confirmation function of the primary circuit. In this power failure detection circuit, the ground circuit of the primary side circuit and the secondary side circuit are independent from each other. Therefore, the auxiliary power source 105 cannot receive power from the secondary side circuit. A DC power supply circuit is required, and the auxiliary power supply has a problem that power consumption cannot be ignored due to poor efficiency. In addition, when a power failure occurs in the AC power supply, it is impossible to detect a power failure unless the capacitor 103 is discharged and the voltage drops, so it takes time to detect the power failure and it is difficult to detect a power failure such as a momentary power failure. There was a problem of being.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a power supply apparatus that can supply a sufficient amount of power during a power failure, has a simple structure, and is economical. To do.

Means for solving the problem

In order to solve the above technical problems, a power supply device according to the present invention includes a rectifier 2 that rectifies an AC voltage supplied from an AC power supply, and a smoothing connected to the rectifier, as shown in FIG. Capacitor 4 and this smoothing capacitor are connected in parallel via resistor 8, and a voltage stabilization circuit provided with voltage holding capacitor 6 having a larger capacity than the smoothing capacitor, and an output voltage from this voltage stabilization circuit Voltage is stepped down by DC to DC conversion This is a configuration having a conversion circuit 14 and a power failure detection circuit 12 for detecting a power failure of the AC power source.

The power supply device according to the present invention has a configuration in which the capacity of the voltage holding capacitor 6 is formed about 10 to 100 times larger than the capacity of the smoothing capacitor 4.

The power supply device according to the present invention has a configuration in which a power factor correction circuit 13 is connected to the rectifier 2 and an output of the power factor improvement circuit is connected to the smoothing capacitor 4 and the voltage holding capacitor 6. .

[0016] The power failure detection circuit of the power supply device according to the present invention includes a primary side circuit that directly drives the circuit using the AC power supply, and a secondary side circuit that operates by receiving power supply from the voltage conversion circuit. It is the composition which consists of.

[0017] The power failure detection circuit of the power supply device according to the present invention extracts a portion of a predetermined voltage or more from the AC voltage and pulsates and rectifies it, and applies this to the light emitting diode of the photocoupler 24. And a secondary circuit that detects a power failure of the AC power supply based on a change in the ON / OFF cycle of a light receiving transistor of the photopower bra.

[0018] The primary side circuit of the power failure detection circuit converts the alternating voltage into positive and negative pulse signals having a predetermined voltage or higher by the trigger diode 18, and converts the signal to the photo force via the rectifier circuit. The photo power bra is periodically turned on / off by inputting it into the bra 24, and when the AC power source falls below the predetermined voltage due to a power failure or step-down, the trigger diode is kept non-conductive and the photo power bra is turned off. In this configuration, the on / off cycle of the light receiving transistor is changed.

[0019] The primary side circuit of the power failure detection circuit applies a current obtained by rectifying the AC voltage to the constant voltage diode 50, and connects the gate terminal of the bidirectional thyristor 54 to the force sword terminal of the constant voltage diode. Then, the bidirectional voltage thyristor is made conductive by the conduction of the constant voltage diode by the breakdown voltage, thereby turning on the photo force bra 24, and the bidirectional thyristor is made non-conductive when the AC voltage is changed. The photobra is turned on and off periodically by turning off the power bra, and in the event of a power failure of the AC power supply, the bidirectional thyristor is kept non-conductive to turn on and off the light receiving transistor of the photopower bra. Zhou It is a configuration that changes the period.

[0020] The power failure detection circuit of the power supply device according to the present invention includes: And a secondary side circuit that is connected to the primary side circuit to be applied to the AC power source and detects a power failure of the AC power source based on a change in the ON / OFF cycle of the light receiving transistor of the bidirectional photo force bra. It is the composition which consists of.

[0021] The primary side circuit of the power failure detection circuit converts the alternating voltage into positive and negative pulsed signals of a predetermined voltage or higher by the trigger diode 18 and converts it into the bidirectional photopower block 40. The bidirectional photo power bra is periodically turned on and off, and when the AC power supply drops below the predetermined voltage due to a power failure or step-down, the trigger diode is kept non-conductive to maintain the bidirectional photo power bra. In this configuration, the ON / OFF cycle of the light receiving transistor of the bra is changed.

[0022] The secondary circuit of the power failure detection circuit is connected in parallel with the light receiving transistor, and repeats discharging and charging based on the periodic on / off of the light receiving transistor, and the voltage of the capacitor and the reference voltage Comparator 34 for comparing the difference, and when the ON / OFF cycle of the light receiving transistor changes, the comparator detects a power failure of the AC power supply when the charging voltage of the capacitor exceeds the reference voltage. It is a structure to do.

[0023] In order to calculate the time during which power can be supplied to the voltage stabilization circuit based on a change in the terminal voltage of the voltage holding capacitor in the event of a power failure, the terminal voltage of the voltage holding capacitor is changed to a digital voltage. This is a configuration provided with an AD converter for conversion.

The invention's effect

According to the power supply device of the present invention, the smoothing capacitor connected to the rectifier and the smoothing capacitor are connected in parallel via the resistor, and the voltage holding capacitor having a larger capacity than the smoothing capacitor is provided. A configuration with a voltage stabilization circuit, a voltage conversion circuit, and a power failure detection circuit has been adopted, so that it has excellent durability with a simple configuration, and in the event of a power failure, a power supply sufficient to protect the electronic device to which power is supplied from the voltage holding capacitor. In addition, the power failure can be detected quickly and accurately by detecting the power failure. There is an effect.

[0025] According to the power supply device of the present invention, the voltage holding capacitor has a capacity that is 10 to 100 times larger than that of the smoothing capacitor 4. There is an effect that a sufficient amount of power can be supplied for the treatment.

[0026] According to the power supply device of the present invention, since the power factor correction circuit is connected to the rectifier and the output of the power factor correction circuit is connected to the smoothing capacitor and the voltage holding capacitor, the voltage rises. Capacitor can be charged at a high voltage with a high voltage, so that a large amount of charge can be held relative to the capacity of the capacitor. The power supply of the necessary voltage can be supplied from the voltage conversion circuit until just before the time is reached, and the efficiency is further improved. Further, the current is kept low, so that the power consumption of the circuit is reduced.

[0027] According to the present invention, the power failure detection circuit includes a primary side circuit that drives a circuit by directly using an AC power supply, and a secondary side circuit that operates by receiving power supply from the voltage conversion circuit. Therefore, an energy-saving circuit with a simple circuit configuration and low power loss can be configured on the primary side circuit, and the secondary side circuit can receive power supply from the voltage stabilization circuit. There is an effect that can be achieved.

[0028] According to the present invention, the power failure detection circuit includes a primary circuit that extracts a portion of a predetermined voltage or more from an AC voltage and applies the extracted portion to the photopower bra, and an AC power The primary side circuit uses an AC power supply directly to drive the circuit, so there is no need to supply additional auxiliary power to the primary side circuit. It is easy to configure and saves energy with low power consumption. In addition, a power failure and momentary power failure can be detected in a short period of the AC power supply unit cycle. There is an effect that notification can be performed.

[0029] According to the present invention, the primary side circuit of the power failure detection circuit converts the AC voltage into a pulsed signal by the trigger diode, periodically turns on and off the photo power bra, and the above-mentioned cycle is detected in the event of a power failure. Since the configuration is changed, the number of parts is small and the circuit can be easily configured, which is economical. [0030] According to the present invention, the primary circuit of the power failure detection circuit is configured to turn on and off the photo power plastic by the constant voltage diode and the bidirectional thyristor, and to change the on / off cycle of the photo power bra in the event of a power failure. Therefore, it has the effect of being economical because a circuit can be configured with simple parts.

[0031] According to the present invention, the power failure detection circuit includes a primary circuit that applies a pulsed AC signal extracted from a portion having a predetermined voltage or more to the bidirectional photo power bra, and an on / off of the bi-directional photo power bra. Because the primary side circuit uses an AC power source as the drive power for the circuit, a separate auxiliary power source is supplied to the primary side circuit. It is not necessary to reduce power consumption and save energy, and since AC signals are used without being rectified, the number of circuit parts is reduced and the economy is reduced. Power outages and momentary power outages are detected, and the power supply destination electronic device can be notified of power outages quickly.

[0032] According to the present invention, the primary side circuit of the power failure detection circuit is configured to periodically turn on and off the bidirectional photo power bra by the trigger diode, and to change the above cycle in the event of a power failure. Can be achieved with a simple circuit configuration that is greatly reduced, so that it is advantageous in terms of economy.

[0033] According to the present invention, the secondary side circuit of the power failure detection circuit employs a configuration in which the comparator detects a power failure of the AC power source when the ON / OFF period of the light receiving transistor changes. Power outages and momentary power outages are detected within a short period of the unit cycle, and the power outage electronic device can be notified of power outages quickly.

[0034] According to the present invention, the AD converter that converts the terminal voltage of the voltage holding capacitor to digital is employed in the voltage stabilization circuit. It is possible to predict the power supply time during which the shutdown process can be performed, and it is possible to schedule the maximum possible process within this time and perform an efficient shutdown process.

Brief Description of Drawings

FIG. 1 is a circuit diagram of a power supply device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of another voltage stabilization circuit according to the embodiment. FIG. 3 is a circuit diagram of a first power failure detection circuit according to the embodiment.

FIG. 4 is an operation explanatory diagram of the secondary circuit in the power failure detection circuit according to the embodiment.

FIG. 5 is a circuit diagram of a second power failure detection circuit according to the embodiment.

FIG. 6 is a circuit diagram of a third power failure detection circuit according to the embodiment.

FIG. 7 is a circuit diagram of a fourth power failure detection circuit according to the embodiment.

FIG. 8 is a circuit diagram of a fifth power failure detection circuit according to the embodiment.

FIG. 9 is a circuit diagram of a sixth power failure detection circuit according to the embodiment.

FIG. 10 is a circuit diagram of a voltage stabilization circuit using the AD converter according to the embodiment.

FIG. 11 is a diagram showing changes in the terminal voltage of the voltage holding capacitor during a power failure.

FIG. 12 is a circuit diagram of another voltage stabilization circuit using the AD converter according to the embodiment.

FIG. 13 is a circuit diagram of a power supply device according to a conventional example.

FIG. 14 is a circuit diagram of a power failure detection circuit according to a conventional example.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of a power supply device according to the present invention will be described with reference to the drawings.

FIG. 1 shows a power supply device according to an embodiment. This power supply device has a voltage stabilization circuit 1, a voltage conversion circuit 14 and a power failure detection circuit 12 (first power failure detection circuit), and is stable as an uninterruptible power supply to electronic devices (computer devices, etc.) to be supplied. Supply DC power to

[0037] The voltage stabilizing circuit 1 includes a bridge-type rectifier 2 for full-wave rectification, a smoothing capacitor 4, a voltage holding capacitor 6 that stores and holds charges, a resistor 8, and a diode 10. The smoothing capacitor 4 is mainly used for the purpose of smoothing, and has a capacity comparable to that of a smoothing capacitor used in a normal smoothing circuit. The smoothing capacitor 4 is connected to the rectifier 2 in parallel. The voltage holding capacitor 6 is connected in parallel to the smoothing capacitor 4 via a resistor 8, and the electric charge accumulated in the voltage holding capacitor 6 is output via a diode 10.

[0038] As described above, in the voltage stabilization circuit 1, the capacitors are separated into the smoothing capacitor 4 and the voltage holding capacitor 6, and thereby the smoothing capacitor 4 is formed in a small capacity to be mainly smoothed. In addition, the voltage holding capacitor 6 is formed with a large capacity to supply sufficient stored charge during a power failure. The voltage holding capacitor 6 is slowly charged through the resistor 8, thereby preventing an excessive inrush current from being generated in the voltage holding capacitor 6 at the start-up when no charge is accumulated.

In this embodiment, the capacity of the smoothing capacitor 4 is 100 μF to 300 μF, and the capacity of the voltage holding capacitor 6 is 1000 μF to 30000 μF. This capacity can be further increased. In this case, the problem of discharge treatment for ensuring safety occurs. In this way, the capacity of the voltage holding capacitor 6 can be formed to be considerably larger than the capacity of the smoothing capacitor 4 (possibly 10 to 1000 times), but practically about 10 to 100 times. In order to secure a sufficient voltage holding time, 20 times to 100 times is appropriate.

[0040] The charging time of the voltage holding capacitor 6 can be adjusted by adjusting the resistance value of the resistor 8. The resistance value of the resistor 8 may be set so that charging is completed within the time when the startup operation system completes the startup process in the computer device to which power is supplied. Here, the resistance value of the resistor 8 is lk Ω.

[0041] At the time of a power failure, the charge of the smoothing capacitor 4 is immediately discharged. However, the charge of the voltage holding capacitor 6 is output through the diode 10 for a sufficient time. It can be safely shut down at any time. The voltage conversion circuit 14 is a circuit that steps down a DC voltage to a predetermined DC voltage by DC-DC conversion. The voltage conversion circuit 14 steps down the primary side voltage to generate a secondary side voltage, but can always generate a constant secondary side voltage with respect to fluctuations in the primary side voltage.

FIG. 2 is a circuit diagram in which a power factor correction circuit 13 (PFC circuit: Power Factor Cont roller) is added to the voltage stabilization circuit 1. The power factor correction circuit 13 is a circuit that improves the power factor and regulates harmonics, and includes a capacitor 3, a coil 5, a switching circuit 7 using a transistor, a resistor 9, a voltage limiting circuit 19 including an IC, and a diode 11.

The power factor correction circuit 13 rectifies an AC power supply (AC) by a rectifier 2, passes through a coil 5, is turned on / off by a switching circuit 7, and thereby the back electromotive force of the coil 5 is converted to a diode 11 And stored in the smoothing capacitor 4. Further, the voltage of the smoothing capacitor 4 is limited by the voltage limiting circuit 19 so that it does not exceed a predetermined voltage (for example, 370 V), and is output.

[0044] By interposing the power factor correction circuit 13 between the rectifier 2 and the smoothing capacitor 4, a current waveform that approximates the voltage waveform is artificially created, and the harmonic current is suppressed to suppress the power factor. To improve. When a power factor correction circuit is used, the voltage rises, but the current is suppressed to a low level to reduce the power consumption of the circuit.Furthermore, the voltage of the smoothing capacitor 4 and the voltage holding capacitor 6 is increased to increase the charge. Accumulation efficiency is also improved. In addition, since the charging voltage of the voltage holding capacitor 6 is high, the power of the required voltage can be supplied from the voltage conversion circuit 14 for a long period of time until this voltage drops and becomes a low voltage that can be converted, which is efficient. .

FIG. 3 shows the first power failure detection circuit 12. The power failure detection circuit 12 is connected to the primary side circuit to which the AC power to be detected is input, and the primary side circuit is connected to the primary side circuit via the photopower bra 24, and is electrically insulated from the primary side circuit. With secondary circuit. In the primary side circuit, the AC power source itself is used as the power source for driving the circuit. For this reason, the primary side circuit and the secondary side circuit are separated from each other by using a photo power bra. . Further, the secondary side circuit uses the DC power source from the voltage conversion circuit 14 as an auxiliary power source. The photo power bra 24 includes a light emitting diode and a light receiving transistor that operates by receiving the light emitting diode.

The primary circuit includes a resistor 15 and a capacitor 16 that form a CR circuit, a trigger diode (DIAC) 18, a full-wave rectifier diode 22, a resistor 20, and a photocoupler 24. The trigger diode 18 suddenly becomes conductive when a voltage of a predetermined level or higher is applied, and the photo-power bra 24 is turned on by the conduction of the trigger diode 18.

The secondary side circuit connected via the photo force bra 24 includes a resistor 26, a capacitor 28, voltage dividing resistors 30 and 32, and a comparator 34. The comparator 34 compares the inputs from the two input terminals (+ terminal, − terminal). The capacitor 28 is connected in parallel with the light receiving transistor of the photocoupler 24, and the capacitor 28 is connected to the input terminal (+ terminal) of the comparator 34. On the other hand, the reference voltage is input to the input terminal (one terminal) of the comparator 34. A power source 36 for driving the secondary circuit is supplied from the voltage conversion circuit 14. [0048] The primary side circuit of the first power failure detection circuit is a time constant circuit composed of a resistor 15 and a capacitor 16 connected to an AC power source (AC), and the capacitor 16 is charged by the AC power source, When this charging voltage reaches the on-voltage of the trigger diode 18, the trigger diode 18 becomes conductive. Then, the electric charge charged in the capacitor 16 passes through the trigger diode 18 and is further rectified through the diode 22, and when this passes through the photocoupler 24, the light emitting diode emits light, and this is received by the light receiving transistor. Photo Power Bra 24 is turned on.

On the other hand, in the secondary circuit, as shown in the voltage waveform diagram of FIG. 4, the discharge of the capacitor 28 is performed through the light receiving transistor of the photocoupler 24 according to the ON state of the photopower bra 24, and the capacitor 28 The voltage drops abruptly (the part of the voltage waveform in Figure 4 that falls to the right). This phenomenon continues in the primary circuit while the capacitor 16 is discharged through the trigger diode 18 (until the breakover voltage), and in this short period the capacitor 28 is discharged to almost zero voltage.

[0050] When the voltage of the capacitor 16 in the primary circuit decreases due to the periodic change in the AC voltage waveform of the AC power supply, the trigger diode 18 becomes non-conductive and the photopower bra 24 also turns off. When the photocoupler 24 is turned off, the capacitor 28 in the secondary circuit is charged and the voltage rises (the portion of the voltage waveform in FIG. 4 that rises to the right). In the voltage waveform in Fig. 4, the time axis represents the case where the AC power supply is 50 Hz (half-wave waveform every 10 ms). This voltage waveform indicates that the trigger diode 18 repeats the conduction / non-conduction cycle every 10 ms, thereby repeating the on / off state of the photocoupler 24. Thus, the voltage of the capacitor 28 has a voltage waveform that is repeated in a sawtooth manner.

[0051] As described above, the primary side circuit has a configuration in which the rectified and pulsed AC power source is used as it is for driving the photocabler 24, and therefore, this circuit does not require an auxiliary power source. In the CR circuit in the primary circuit, for example, the resistor 15 can be set to 500 kΩ or more, and the capacitor 16 can be set to about 0.01 zF. For this reason, the current flowing in the primary circuit can be kept very low, from several tens of μ 百 to several hundred μΑ or less (about several hundred mA in a circuit using a conventional auxiliary power supply), and almost all power is required. And not.

[0052] Here, there is a power outage of AC power supply, an instantaneous (several tens of ms to several hundred ms) power outage or a voltage drop If it occurs, the charging voltage to the capacitor 16 in the primary circuit is reduced or eliminated. For this reason, the voltage applied to the trigger diode 18 does not reach the breakover voltage, and conduction every 10 ms stops. As a result, the off-state of the photocoupler 24 continues and the secondary circuit capacitor 28 is continuously charged, and the charging voltage of the capacitor 28 rises to the voltage (VI) of the power supply 36 of the secondary circuit. During this time, the threshold level L is immediately exceeded (the dotted line portion of the voltage waveform in Fig. 4 rising to the right).

[0053] The threshold level L corresponds to the reference voltage of the comparator 34, and when this level L is exceeded, a power failure is detected. By setting this level L appropriately, it is possible to detect even 50Hz half-wave, that is, 10ms power failure. Here, the threshold level L is approximately twice the peak value of the sawtooth waveform in the voltage waveform of FIG.

Then, a voltage exceeding the reference voltage of the input terminal (one terminal) is applied to the input terminal (+ terminal) of the comparator 34, and a detection signal (OUT) is output from the comparator 34. This detection signal is a power failure detection signal generated when the trigger diode 18 is turned off due to a power failure.

[0055] Therefore, the power failure detection circuit can detect a momentary power failure that occurs during a half-wave of 50 Hz, that is, 10 ms after a power failure occurs in the AC power supply (50 Hz). In addition, the time required to detect this power failure is 20 ms at maximum when the threshold level is set to L (until the voltage at the part rising to the right in Fig. 4 reaches 0 to L). Later, detection becomes possible after a minimum of 10 ms (until the voltage in the dotted line on the right in Fig. 4 reaches L / 2 to L).

Next, the operation of the power supply device will be described.

When the AC power supply (AC) is turned on, charging of the smoothing capacitor 4 is started after passing through the rectifier 2, and then the voltage holding capacitor 6 is charged. At this time, the voltage holding capacitor 6 is charged with a small current of about several tens of mA to one hundred mA because the resistor 8 is connected in series. The voltage smoothed by the smoothing capacitor 4 is input to the voltage conversion circuit 14. Since the smoothing capacitor 4 normally has a higher voltage than the voltage holding capacitor 6, the smoothing action is performed by the smoothing capacitor 4. Voltage conversion circuit 14 Drops the DC voltage to a predetermined voltage by DC-DC conversion, and outputs this DC power to the computer equipment to which it is supplied.

[0057] In general, a computer device requires several tens of seconds to several minutes from when the power is turned on until the operation system completes startup. Therefore, if the voltage holding capacitor 6 can be charged during the startup, there will be no problem with the power supply after startup. Depending on the capacity of the voltage holding capacitor 6, it can be considered that it can be sufficiently charged with a current of 10 mA or less.

[0058] Here, when an AC power failure or a momentary (several tens to hundreds of ms) power failure occurs, the power failure detection circuit 12 detects this power failure after 10 ms to 20 ms. Notify the computer of the detection signal. The computer device immediately starts the shutdown process. On the other hand, the voltage stabilizing circuit 1 starts discharging from the voltage holding capacitor 6 following the smoothing capacitor 4, DC power is directly supplied to the computer device via the diode 10, and the shutdown process is continued. .

[0059] Thus, in the power supply device, the voltage holding capacitor 6 can be formed with a very large capacity, so that a sufficient amount of power can be supplied to the computer device during a power failure. For this reason, the backup system using the conventional storage battery becomes unnecessary. In addition, compared with a storage battery, the electrolytic capacitor used as the voltage holding capacitor 6 has a long life, so that maintenance is not required and the operation cost can be reduced.

[0060] Further, the storage battery is required to have a charging circuit for charging and guaranteeing self-discharge. In the above power supply device, these circuits are unnecessary, and the power supply device can be configured extremely safely and efficiently. Therefore, it is an ideal power supply for a computer device to which power is supplied. In addition, since the voltage holding capacitor 6 exists, the smoothing capacitor 4 only needs to serve as a smoothing capacitor and has a small capacity.

[0061] On the other hand, the power failure detection circuit 12 is configured to directly drive the photo power bra using an AC power source and a signal obtained by rectifying the AC power source, and therefore, a DC auxiliary power source is not required for the primary side circuit. For this reason, the number of parts is reduced, the economy is excellent, and the power consumption is small, so that energy can be saved. In addition, it is difficult to detect a momentary power failure (several tens of ms to several hundred ms) that is currently a problem with the conventional detection circuit. The instantaneous power failure can be detected in a short time.

FIG. 5 shows the second power failure detection circuit 17. This power failure detection circuit has a resistor 15, a capacitor 16, a trigger diode 18, a bidirectional photopower bra 40 and a resistor 20 in the primary side circuit. The bidirectional photo power bra 40 is a photo power bra corresponding to an AC input in which a light emitting diode is connected in antiparallel to the input side. In the power failure detection circuit 17, since the trigger diode 18 can be directly connected to the bidirectional photo power bra 40, the rectifying diode can be reduced and the cost can be reduced. The secondary side circuit connected via the bidirectional photo power bra 40 is the same as the secondary side circuit of the first power failure detection circuit 12.

[0063] In the primary circuit, the capacitor 16 is charged by an AC power supply (AC), and when the voltage of the capacitor 16 exceeds a predetermined voltage, the trigger diode 18 is turned on and connected to the trigger diode 18 in series. Drive bidirectional photo power bra 40. Then, the light emitting diode in the bidirectional photo force bra 40 emits light, the light receiving transistor becomes conductive, and the bidirectional photocoupler 40 is turned on. Eventually, when the charging voltage of the capacitor 16 decreases, the trigger diode 18 becomes non-conductive, and the bidirectional photo power bra 40 is turned off.

[0064] Then, the capacitor 16 is charged again by the AC power source (the sign of the sine wave is inverted), and when the on-voltage of the trigger diode 18 is reached, the capacitor 16 becomes conductive, and the bidirectional photo force bra 40 is turned on. Become. This bidirectional photo power bra 40 repeats the on / off state (100 times / sec) in accordance with the cycle of the AC power supply (50 Hz). While the bidirectional photocoupler 40 is periodically turned on and off, the capacitor 28 of the secondary side circuit cannot rise above a certain voltage, and the detection signal from the comparator 34 is not output.

[0065] Here, when a power failure or voltage drop occurs in the AC power supply, the voltage of the capacitor 16 decreases, the trigger diode 18 remains non-conductive, and the bidirectional photo power bra 40 also remains off. In the secondary circuit, the capacitor 28 continues to be charged, a voltage exceeding the reference voltage is applied to the input terminal (+ terminal) of the comparator 34, and a power failure detection signal is output from the comparator 34. The bidirectional photo force bra 40 operates with respect to alternating current, and the primary side circuit is configured to use an alternating current power source for driving the bidirectional photo force bra 40 as it is. Is unnecessary.

FIG. 6 shows a third power failure detection circuit 45. This power failure detection circuit is The circuit has rectifier 42 for full-wave rectification, capacitor 44, resistors 43, 46, 48, constant voltage diode 50, thyristor connection circuit consisting of NPN transistor 52 and PNP transistor 53, and photopower bra 24 . The secondary side circuit connected via the photo force bra 24 is the same as the secondary side circuit of the first power failure detection circuit 12. This power failure detection circuit 45 can use a transistor and a constant voltage diode without using a trigger diode or thyristor, and can make the circuit element an IC.

[0067] The primary side circuit rectifies the AC power source with the rectifier 42, and when the voltage of the capacitor 44 storing the AC power exceeds the breakdown voltage of the constant voltage diode 50, the current flows to the constant voltage diode 50 through the base of the transistor 53. Current flows from the collector of the transistor 53 to the base of the transistor 52. Since the collector of the transistor 52 is connected to the base of the transistor 53, the base current of the transistor 53 further increases, and both the transistors 52 and 53 are completely turned on immediately. When the transistors 52 and 53 are turned on, the photopower bra 24 connected in series with the transistors 52 and 53 is turned on.

[0068] When the transistors 52 and 53 are turned on, the capacitor 44 is discharged through the resistor 46. When the charging voltage of the capacitor 44 is lost and the positive feedback of the transistors 52 and 53 cannot be maintained, the transistors 52 and 53 are turned off. It becomes a state. Therefore, the resistor 43 must always charge the capacitor 44 with such a current that the positive feedback of the transistors 52 and 53 cannot be maintained. As described above, while the photocoupler 24 is periodically turned on and off (100 times / 50 Hz), the capacitor 28 of the secondary side circuit cannot rise above a certain voltage, and the detection from the comparator 34 occurs. No signal is output.

[0069] Here, when a power failure or voltage drop occurs in the AC power supply, the voltage of the capacitor 44 cannot exceed the breakdown voltage of the constant voltage diode 50, so that the transistors 52 and 53 cannot be turned on, and the photopower Bra 24 remains off. In the secondary circuit, the capacitor 28 continues to be charged, a voltage exceeding the reference voltage is applied to the input terminal (+ terminal) of the comparator 34, and a power failure detection signal is output from the comparator 34. Further, since the primary side circuit is configured to rectify an AC power source and use it for driving the photopower bra 24, an auxiliary power source is not required for this circuit.

FIG. 7 shows a fourth power failure detection circuit 47. This power failure detection circuit is a trigger element. A bidirectional thyristor 54 is used as a child. The bidirectional thyristor 54 is basically the same in operation as the transistors 52 and 53, and both are equivalent. The bidirectional thyristor 54 is used for the purpose of conducting the bidirectional thyristor 54 by flowing a gate current from the bidirectional thyristor 54 toward the constant voltage diode 50. Because the direction is different, it cannot be used for this circuit.

The power failure detection circuit 47 includes a rectifier 42, a capacitor 44, resistors 43, 46, and 48, a constant voltage diode 50, a bidirectional thyristor 54, and a photocoupler 24 on a primary side circuit. The secondary side circuit connected via the photo force bra 24 is the same as the secondary side circuit of the first power failure detection circuit 12.

[0072] This primary side circuit rectifies the AC power supply by the rectifier 42, and when the voltage of the capacitor 44 storing the AC power exceeds the breakdown voltage of the constant voltage diode 50, the constant voltage diode is passed through the gate of the bidirectional thyristor 54. A current flows through 50, and the bidirectional thyristor 54 becomes conductive by this gate current. Then, the photo force bra 24 connected in series to the bidirectional thyristor 54 is turned on.

[0073] When the bidirectional thyristor 54 is turned on, the capacitor 44 is discharged through the resistor 46, the charging voltage of the capacitor 44 is lost, and when the current does not flow to the bidirectional thyristor 54, the gate function is restored and the bidirectional function is restored. The thyristor 54 becomes non-conductive, and the photo force bra 24 is turned off. In this way, while the AC voltage waveform from the AC power supply changes normally and periodically and the photocoupler 24 is periodically turned on and off, it is detected from the comparator 34 of the secondary side circuit. No signal is output.

Here, when a power failure or voltage drop occurs in the AC power supply, the voltage of the capacitor 44 cannot exceed the breakdown voltage of the constant voltage diode 50. For this reason, the gate current does not flow through the bidirectional thyristor 54, and the bidirectional thyristor 54 cannot shift to the conductive state, so that the photo force bra 24 is maintained in the OFF state. In the secondary circuit, the capacitor 28 continues to be charged, and a power failure detection signal is output from the comparator 34. Further, since the primary side circuit is configured to rectify an AC power source and directly use it for driving the photopower bra 24, an auxiliary power source is not necessary for this circuit.

FIG. 8 shows a fifth power failure detection circuit 55. This power failure detection circuit is a trigger element. The thyristor 60 is used for the child. Instead of the thyristor 60, a thyristor connection circuit including the NPN transistor 52 and the PNP transistor 53 can be employed. The power failure detection circuit 55 includes a rectifier 42, a capacitor 44, resistors 43, 46, 58, a constant voltage diode 56, a photocoupler 24, and a thyristor 60 on a primary side circuit. The secondary side circuit connected via the photo force bra 24 is the same as the secondary side circuit of the first power failure detection circuit 12.

[0076] This primary side circuit rectifies the AC power supply (AC) by the rectifier 42, and when the voltage of the capacitor 44 storing the rectifier exceeds the breakdown voltage of the constant voltage diode 50, the constant voltage diode 56 becomes conductive. . Due to the conduction of the constant voltage diode 56, a gate current flows through the thyristor 60 and the thyristor 60 becomes conductive, and the photocoupler 24 connected in series to the thyristor 60 is turned on.

[0077] When the capacitor 44 is discharged, no current flows through the thyristor 60, the gate function is restored, the thyristor 60 is turned off, and the photo power bra 24 is also turned off. When the voltage of the capacitor 44 rises, the thyristor 60 and the photocoupler 24 are turned on again by the conduction of the constant voltage diode 56, and the photocoupler 24 repeats the on / off state according to the cycle of the AC power supply.

Here, when a power failure or voltage drop occurs in the AC power supply, the voltage of the capacitor 44 cannot exceed the breakdown voltage of the constant voltage diode 56. For this reason, the gate current does not flow through the thyristor 60, and the thyristor 60 cannot shift to the conductive state, and the photopower bra 24 is maintained in the off state. As a result, the capacitor 28 continues to be charged in the secondary circuit, and the comparator 34 power failure detection signal is output. The primary circuit does not require an auxiliary power supply.

FIG. 9 shows a sixth power failure detection circuit 69. This power failure detection circuit uses a bidirectional thyristor 54 as a trigger element, and two constant voltage diodes 70 and 71, and does not rectify the AC power supply. 40 is driven. In this power failure detection circuit 69, the bidirectional thyristor 54 can be replaced with a transistor thyristor connection circuit as in the third power failure detection circuit. In this case, since current must flow in both directions, two thyristor connection circuits using transistors are used. In addition, it requires a circuit configuration that allows current to flow only in one direction to the circuit, which complicates the circuit.

This power failure detection circuit 69 has a capacitor 64, resistors 62, 66, 68, constant voltage diodes 70, 71, a bidirectional thyristor 54, and a bidirectional photocoupler 40 on the primary side circuit. The secondary circuit connected via the bidirectional photo force bra 40 is the same as the secondary circuit of the first power failure detection circuit 12. The constant voltage diodes 70 and 71 are connected in series with opposite polarities so as to operate with respect to both positive and negative voltages.

[0081] In this primary side circuit, when the capacitor 64 is charged by an AC power supply (AC) and the voltage of the capacitor 64 exceeds the breakdown voltage of the constant voltage diode 70 (or 71), the constant voltage diode 70 ( Or 71) conducts. Due to the conduction of the constant voltage diode 70 (or 71), a gate current flows through the bidirectional thyristor 54 to cause the bidirectional thyristor 54 to conduct, and the bidirectional photopower bra 40 connected in series to the bidirectional thyristor 54 is provided. Turns on.

Due to the discharge of the capacitor 64, no current flows through the bidirectional thyristor 54, the gate function is restored, the non-conducting state remains, and the bidirectional photopower bra 40 is also turned off. Eventually, when the voltage of the capacitor 64 rises, the bidirectional voltage thyristor 54 and the bidirectional photo power bra 40 are turned on again by the conduction of the constant voltage diode 70 (or 71), and the bidirectional photo diode 40 is turned on according to the cycle of the AC power supply. The force bra 40 is repeatedly turned on and off.

[0083] Here, when a power failure or voltage drop occurs in the AC power supply, the voltage of the capacitor 64 cannot exceed the breakdown voltage of the constant voltage diode 70 (or 71). For this reason, since no gate current flows through the bidirectional thyristor 54, the bidirectional thyristor 54 cannot enter the conductive state, and the bidirectional photopower plug 40 maintains the OFF state. As a result, the capacitor 28 continues to be charged in the secondary circuit, and a power failure detection signal is output from the comparator 34. The primary circuit does not require an auxiliary power supply.

[0084] Regarding the second to sixth power failure detection circuits, the same effect as that of the first power failure detection circuit is obtained, and the photo power bra is driven by directly using the AC power supply and a signal obtained by rectifying the same. Therefore, this primary side circuit does not require a DC auxiliary power supply.Therefore, the number of parts is reduced, it is economical, power consumption is small, and energy saving is achieved. Power outages and momentary power outages are detected in a short period of unit cycle. There is an effect that a power failure can be quickly notified to the electronic device to which power is supplied.

FIG. 10 is a circuit diagram in which an AD converter 74 is added to the voltage stabilization circuit shown in FIG. The voltage stabilizing circuit shown in FIG. 10 has the same basic circuit configuration as that of the voltage stabilizing circuit of FIG. 2, and the same components are denoted by the same reference numerals and detailed description thereof is omitted.

The AD converter 74 is connected between both terminals of the voltage holding capacitor 6, measures the output voltage of the voltage holding capacitor 6, converts it to a digital voltage, and outputs it. The output of the AD converter 74 is input to a computer device to which power is supplied, and the computer device calculates a supplyable time during which a power supply can be received from the voltage holding capacitor 6 in the event of a power failure. The computer apparatus ends the shutdown operation within the supply available time. The power supply for the AD converter 74 is supplied from the voltage conversion circuit 14.

[0087] When the internal processing program is activated and the computer device receives a power failure detection signal from the power failure detection circuit 12, the computer device changes the output voltage of the voltage holding capacitor 6 through the AD converter 74 for a certain period of time. Measure every time. This voltage holding capacitor 6 holds a predetermined voltage (for example, 370 V) immediately before the power failure, and discharge starts at the same time as the power failure, and the terminal voltage decreases. Capacitance of the voltage holding capacitor 6 (C), between a stored energy (W) and capacitor terminal voltage (V) is, W = CV ^2/2 relationship is satisfied, the power supply to the computer system The terminal voltage (V) of the accompanying voltage holding capacitor 6 is expected to change with time as shown in Fig. 11.

[0088] Here, when the terminal voltage is relatively high, the rate of voltage drop is relatively linear. Therefore, the computer device considers that the rate is constant and can be supplied with power. Predict. For this reason, the computer device checks the time (lm s to 100 ms (preferably 10 ms to 20 ms) when the terminal voltage (V) of the voltage holding capacitor 6 starts to decrease (P_1: detection level). )) Measure the voltage every time and assume that the rate of this voltage drop is constant thereafter. From the time when the computer device starts to shut down (P-3: Shutdown start time, voltage is 200V, for example) Until the voltage reaches the minimum voltage at which the device can operate (P-2: minimum operating voltage, eg 120V) The power supply available time (T) is calculated and determined. For example, when the power failure detection signal is received, the terminal voltage of the voltage holding capacitor 6 is measured, and thereafter, the terminal voltage is measured once to several times at the predetermined intervals, and then the average voltage drop is reduced. Find the percentage. In this embodiment, the rate of voltage drop was determined from the terminal voltage at two points, the point when the power failure detection signal was received and the point 10 ms later.

Then, the computer apparatus performs a shutdown process as much as possible within the range of the power supply possible time (T). For this reason, the computer device can schedule the maximum possible processing within this time by predicting the available time for shutdown processing in the event of a power failure. Shutdown processing can be performed.

FIG. 12 is a circuit diagram in which a CPU circuit 76 is further added to the AD converter 74 of the voltage stabilization circuit shown in FIG. The CPU circuit 76 includes a CPU, a memory, and a control circuit, and can perform predetermined arithmetic processing, etc., and calculates the supplyable time (T) for the shutdown operation based on the digital voltage output from the AD converter 74. And output this. Then, the computer device performs a shutdown process based on the supply available time. In the CPU circuit 76, the calculation contents for determining the supplyable time are the same as those performed by the computer device described above. The power supply of the CPU circuit 76 is supplied from the voltage conversion circuit 14.

[0091] Usually, when many processes are running on the computer device, the computer device may not be able to guarantee that the calculation process of the supplyable time is appropriately performed. In such a case, by providing a dedicated CPU circuit 76 in the voltage stabilization circuit, it is possible to appropriately calculate the supplyable time, reduce the load on the computer device, and improve the reliability of the entire computer device. be able to.

Explanation of symbols

[0092] 2 Rectifier

4 Smoothing capacitor

6 Voltage holding capacitor

12 Power failure detection circuit

13 Power factor correction circuit Voltage conversion circuit Trigger diode Photocoupler Capacitor capacitor /, ° C Bidirectional photocoupler Constant voltage diode Bidirectional thyristor AD converter

Claims

The scope of the claims

[1] a rectifier for rectifying an AC voltage supplied from an AC power source;

A smoothing capacitor connected to the rectifier and a voltage stabilizing circuit connected in parallel to the smoothing capacitor via a resistor, and having a voltage holding capacitor having a larger capacity than the smoothing capacitor;

A voltage conversion circuit that steps down the output voltage from this voltage stabilization circuit by DC-DC conversion;

And a power failure detection circuit for detecting a power failure of the AC power source.

[2] The power supply device according to [1], wherein a capacity of the voltage holding capacitor is about 10 to 100 times larger than a capacity of the smoothing capacitor.

[3] A power factor correction circuit is connected to the rectifier, and an output of the power factor correction circuit is connected to the smoothing capacitor and the voltage holding capacitor. The power supply device according to item 2.

[4] The power failure detection circuit includes a primary side circuit that drives the circuit by directly using the AC power source, and a secondary side circuit that operates by receiving power supply from the voltage conversion circuit. The power supply device according to any one of claims 1 to 3.

[5] The power failure detection circuit extracts a portion of a predetermined voltage or more from the AC power source and pulsates and rectifies it, and applies this to a light emitting diode of a photo power bra. And a secondary side circuit for detecting a power failure of the AC power supply based on a change in the ON / OFF cycle of the light receiving transistor of the photopower bra. The power supply device according to any one of the items in the range 4.

[6] The primary side circuit of the power failure detection circuit converts the alternating voltage into positive and negative pulsed signals exceeding a predetermined voltage by a trigger diode, and inputs this to the photo power bra through a rectifier circuit. And this photo power plastic is turned on and off periodically,

When the AC power supply drops below the predetermined voltage due to a power failure or step-down, the trigger diode is kept non-conductive to change the on / off period of the phototransistor light receiving transistor. The power supply device according to claim 5 in the range.

[7] The primary side circuit of the power failure detection circuit applies a current rectified from the AC voltage to a constant voltage diode, and connects a gate terminal of a bidirectional thyristor to a power sword terminal of the constant voltage diode,

The bi-directional thyristor is made conductive by the conduction of the constant voltage diode by a breakdown voltage, thereby turning on the photo force bra, and when the AC voltage changes, the bi-directional thyristor is made non-conductive and the photo force bra is turned on. Turn the photo power bra on and off periodically,

6. The power supply according to claim 5, wherein, in the event of a power failure of the AC power supply, the on / off cycle of the light receiving transistor of the photopower bra is changed by maintaining the bidirectional thyristor in a non-conductive state. apparatus.

[8] The power failure detection circuit includes a primary side circuit that applies an AC signal obtained by extracting a portion of a predetermined voltage or more from the AC voltage and pulsing positively and negatively to a light emitting diode of a bidirectional photopower bra; A secondary circuit connected via a bidirectional photo force bra and detecting a power failure of the AC power source based on a change in the on / off period of a light receiving transistor of the bidirectional photo force bra. The power supply device according to any one of claims 1 to 4.

[9] The primary side circuit of the power failure detection circuit converts the AC voltage into positive and negative pulse signals exceeding a predetermined voltage by a trigger diode, and inputs the signal to the bidirectional photopower bracket. The bidirectional photo power bra is turned on and off periodically,

When the AC power supply drops below the predetermined voltage due to a power failure or step-down, the trigger diode is kept non-conductive to change the ON / OFF cycle of the light receiving transistor of the bidirectional photopower bra. The power supply device according to claim 8, wherein the power supply device is characterized.

[10] The secondary circuit of the power failure detection circuit is connected in parallel with the light receiving transistor, and a capacitor that repeatedly discharges and discharges based on periodic on / off of the light receiving transistor, and the difference between the voltage of the capacitor and the reference voltage. A comparator for comparing

6. The range according to claim 5, wherein the comparator detects a power failure of the AC power supply when the charging voltage of the capacitor exceeds the reference voltage when the ON / OFF cycle of the light receiving transistor changes. To any one of claims 9 Power supply.

AD converter that converts the terminal voltage of the voltage holding capacitor to a digital voltage in order to calculate the time during which power can be supplied to the voltage stabilization circuit based on the change in the terminal voltage of the voltage holding capacitor in the event of a power failure The power supply device according to any one of claims 1 to 10, wherein a power supply device is provided.