JP2001344046A - Power source device for information device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light and inexpensive power source device for an information processor with a backup function. SOLUTION: A battery constituted of a plurality of nickel hydrogen batteries which are only serially connected and provided with a capacity capable of discharging current quantity requested by an information device and performing the saving processing of the information device two or three times is incorporated in a power source device which supplies operating power at the time of saving processing to the information device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply for an information device provided in an information device such as a personal computer or a network terminal, and more particularly, to a commercial AC power supply (hereinafter referred to as a commercial AC power supply).
It is called "AC power supply". ) Relates to a power supply device having a backup function in the event of a power failure such as a power failure.

[0002]

2. Description of the Related Art There are two types of power supplies for a small information device such as a notebook personal computer: an external power source obtained by converting an AC power source into a direct current by an AC adapter or the like, and an internal power source comprising a secondary battery or the like built in the device. Is often provided. There are two types of use of small information devices: desktop use and portable use. Use AC power for desktop use and use built-in power supply for portable use. However, in the case where a small information device is used on a desk using an AC power source, if a power failure such as a power failure occurs in the AC power source, the built-in power source functions as a backup power source.

FIG. 12 shows a typical power supply system provided in a small information device. As shown in FIG. 12A, the small-sized information device 1 is provided with a DC input terminal 200. By connecting the DC output of the AC adapter 2 to the terminal 200, the small-sized information device 1 is connected from the AC power source 3 to the AC adapter 2. The converted DC external power can be supplied. The small information device 1 includes a battery pack 3
10 and a charging circuit 320. One of the external power supply and the internal power supply supplied from the battery pack 310 is selected by the selector 20 and supplied to the internal power supply circuit 10. The direct current adjusted to the required voltage by the circuit 10 is supplied to the CPU 40 and other circuits inside the information device (not shown).

[0004] As shown in FIG. 12B, a battery pack 310 includes a battery cell 311 connected in series and parallel,
Protection circuit 312 for battery cell 311 and protection circuit 31
And an MPU 313 that controls the operation of the communication device 2 and performs a communication interface function with the CPU 40. The MPU 313 is integrated in a case, and is detachably mounted in a housing of the information device. The state of the battery cell 311 such as the remaining amount is monitored by the CPU 40 through the communication interface, and the charging circuit 320 appropriately controls charging.

That is, when the input from the AC power supply 3 is supplied, the selector 20 selects the external input side, and the battery pack 310 is almost in a no-load state. Also at this time, the CPU 40 monitors the state of the battery pack 310 and operates the charging circuit 320 if necessary. On the other hand, A
When the C power supply is disconnected or a power failure occurs, the selector 20 selects the battery pack 310 and the power supply circuit 1
0 is supplied with power from the battery cell 311. When the power failure state continues and the remaining amount of the battery pack 310 falls below a predetermined amount, the small information device 1 starts a prepared evacuation program based on a command from the CPU 40, and the required evacuation processing ends. Later, the power supply from battery pack 310 is stopped.

[0006]

In the above-mentioned conventional battery pack 310, a lithium ion (Li +) battery is often used as the battery cell 311. However, the lithium ion battery has a protection circuit and a remaining battery due to its characteristics and properties. Since a meter is required, the battery pack 310 using a lithium ion battery as a built-in battery is large, heavy, and expensive. When the small information device 1 is placed on a desk and used with an AC power supply, the battery pack 310 functions only as a backup power supply at the time of a power failure, so providing such a large, heavy, and expensive battery pack is cost-effective. This means that a battery pack of an excessive quality is mounted in view of the effect, which is wasteful. A battery pack 3 having a lithium-ion battery as a built-in battery
In the charging control of No. 10, it is necessary to provide a charging circuit 320 that matches the characteristics of the battery pack 310. Therefore, the battery pack 310 and the charging circuit 320 are limited to a specific combination. There is also a problem that there is no product flexibility, such as being limited.

Further, in information devices such as personal computers, the information devices are rarely used alone, and peripheral devices such as printers and hard disk drives usually operate simultaneously. For this reason, if the start timings of these devices coincide when power is restored after a power failure, an excessive start-up current is superimposed, resulting in an excessive load on the power supply. In the worst case, there is a possibility that the circuit breaker is activated by an excessive current in a transition period, and the power is again cut off.
As described above, the backup battery is subjected to severe conditions such as the occurrence of a new discharge request after the discharge, so that the backup power supply device tends to be expensive.

In the above description, a battery pack detachably attached to a small information device has been described as an example. However, a backup power supply is built in a small information device or other information devices, or externally connected (connected). There is a similar problem in the case.

The present invention has been made in order to solve the above-mentioned deficiencies of the prior art.
To provide a power supply device for an information device having a backup function when a power failure such as a power failure occurs in an AC power source at a low cost, and secondly, it is possible to perform integrated control when starting a plurality of information devices, An object of the present invention is to provide a power supply device for an information device capable of avoiding occurrence of a power supply failure due to superposition of a starting current.

[0010]

According to the present invention, there is provided a power supply device having an internal battery for supplying operating power to an information device during an evacuation process. When the required output voltage is V ₀ , the output current required for the evacuation process is I ₀ , the time required for one evacuation process is τ, the cell voltage is V, and the cell capacity is Ah, n ≧ [V ₀ / V] (however, when [V ₀ / V] is not an integer, n is an integer immediately above n).
Ah> km · I ₀ · τ
(However, k is a value that satisfies k> 1 in the cell capacity margin ratio, m
Is the number of evacuation processes to be compensated, and a value satisfying m ≧ 2. ), And a built-in nickel-metal hydride battery having a discharge rate of C> Ah / I ₀ .

[0011] In the power supply device, the information device is operated a plurality of times (m ≧
2) Since a built-in battery having a capacity capable of executing the backup process is provided, it is possible to cope with a power failure again after the power is restored, which is excellent in practicality and reliability.
In addition, since a built-in nickel-hydrogen (Ni-MH) battery that is resistant to overcharging, overdischarging, and sudden temperature changes as a built-in battery, a strict protection circuit is not required unlike the case of incorporating a lithium-ion battery, The power supply device can be reduced in weight and cost. Furthermore, in recent years, 10
Since a nickel-metal hydride battery capable of obtaining a discharge current of about A and having a discharge rate of about 10 C has been developed, if this kind of nickel-metal hydride battery is used, one to several battery cells are connected in series. Since the backup process can be performed at least twice with the battery and the number of cells used can be significantly reduced, the power supply device can be reduced in weight and cost.

[0012] This power supply unit is provided with a C
Connected to the PU via the communication interface, the CPU
Transmission of power failure information to the server. It is preferable that a communication interface for communicating signals between the power supply device and the information device has compatibility with a communication interface of a standard battery pack mounted on the information device.

With this configuration, the power supply device of the present invention can be applied to a conventional information device as it is, and the desk-top use of the information device with the power supply device of the present invention mounted and the standard type battery pack mounted. Since the information device can be used at any time, the practicality and convenience of the information device can be improved.

Further, the power supply device includes a charging circuit for the nickel-metal hydride battery and a controller for the charging circuit. The control signal output from the controller controls the discharging from the nickel-metal hydride battery and the power supply to the controller itself. Can also.

With this configuration, when it is expected that the power failure of the AC power supply such as a power failure will continue for a predetermined time exceeding the capacity of the built-in battery, the discharge of the built-in battery and the power supply to the controller are automatically performed. Can be cut off, so that the load on the built-in battery can be minimized.

Further, the power of the peripheral device can be controlled to be on / off by a control signal output from the controller.

In this way, the start-up timings of the information device and its peripheral devices can be integratedly controlled by the control signal from the controller, and can be shifted from each other by a predetermined time, so that an excessive start-up current is superimposed when the power is restored. As a result, the load of the power supply does not become excessive, and inconveniences such as a voltage drop and a power outage can be prevented, and the reliability of the power supply device can be improved. In addition, since the battery load can be reduced, it is not necessary to provide an excessive number of battery cells. In this regard, the backup power supply can be reduced in size, weight, and cost.

In this specification, the "evacuation process" refers to a shutdown process in which all the running processes are terminated and the OS is terminated and then the power is turned off, and a process in which the running process is performed is not limited to the data or the data. This means a process including both a suspending process (also called suspend or hibernation) in which all information such as parameters is saved to the hard disk and restored by a recovery process.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram of a power supply device according to the embodiment, FIG. 2 is a perspective view showing an appearance of the power supply device according to the embodiment, and FIG. 3 is a functional circuit diagram of the power supply device according to the embodiment. 4 is a block diagram of a power supply unit of the information device equipped with the power supply device according to the embodiment,
FIG. 5 is a graph showing characteristics of various batteries.

As shown in FIG. 1, a power supply device 30 according to this embodiment includes a built-in battery 31, a charging circuit 32, a controller 33, and a selector 34 in a case 30a. , A communication interface 302 between the controller 33 and a CPU provided in the information device is provided. The voltage on the DC input 300 side is
It is set higher than the built-in battery 31 side. Normally, the DC input 300 side is selected by the selector 34 and D
The signal is output to the C output terminal 301, and at the time of a power failure, the internal battery 31 is selected and output to the DC output terminal 301.

As shown in FIG. 2, the appearance of the case 30a is the same as that of a standard battery pack of an information device to which the power supply device 30 is mounted. The communication interface 302 is also configured in the same manner as the standard battery pack. Therefore, the power supply device 3 according to the present embodiment example
0 is completely compatible with a standard battery pack of an information device to which the power supply device 30 is attached, and is detachably attached to the information device 1 as shown in FIG. By inputting the DC converted from the input 3 to the DC input 300, it is possible to supply operating power to the information device 1 in a normal state and supply backup power to the information device 1 in a power failure. Further, the information device 1 with the power supply device 30 of the present embodiment mounted thereon can be used on a desk and the information device 1 with a standard battery pack mounted thereon can be used portablely, making the information device 1 practical and convenient. Can also be increased. In FIG. 4, reference numeral 10 denotes the information device 1
Reference numeral 20 denotes a selector provided in the information device 1, reference numeral 100 denotes a drive voltage of the information device 1, reference numeral 2
00 denotes a DC input terminal provided in the information device 1.

Hereinafter, the configuration and operation of the power supply device according to this embodiment will be described in more detail with reference to FIGS.

In FIG. 3, reference numeral 35 denotes a switch, reference numeral 36 denotes a regulator, reference numeral 37 denotes a reset circuit, and reference numeral 3 denotes a reset circuit.
Reference numeral 8 denotes a microcomputer, reference numeral 39 denotes a DC / DC converter, and other portions equivalent to those shown in FIG. 1 are denoted by the same reference numerals.

Power supply terminal Vc of microcomputer 38
To c, the higher voltage side of the voltage of the DC input 300 or the output voltage of the built-in battery 31 is selectively applied. DC input 3 as described above
Since the voltage on the 00 side is set higher than that on the built-in battery 31 side, the microcomputer 38 is driven by power supply from the DC input 300 at normal times, and is supplied by power supply from the built-in battery 31 at power failure. The computer 38 is driven.

The microcomputer 38 detects whether there is an abnormality in the input voltage or the presence or absence of a power failure from a signal relating to the voltage and current of the DC input 300 input to the Si terminal. Also,
From the signal related to the voltage and current of the DC output 301 input to the So terminal, the voltage and current of the power supply supplied to the information device 1 and the state of the information device 1 such as short circuit and open are detected. Further, the built-in battery 31 input to the Bs terminal
The remaining amount of the built-in battery 31 is detected from the charge / discharge voltage and charge / discharge current signals. On the other hand, the microcomputer 38 transmits a charging control signal from the Cc terminal to the charging circuit 32, and controls charging of the built-in battery 31 and stopping of charging. Further, a battery output control signal is transmitted from the Bo terminal to the switch 35 provided in the discharge circuit of the built-in battery 31, and on / off control of the switch 35 is performed.

Normally, the output of the DC / DC converter 39 is supplied to the DC output.
Operates with input as operating power. Switch 3
5 and the regulator 36 are both switched on.

When the occurrence of a power failure is detected from a change in the input signal to the Si terminal, the microcomputer 38 sends the information to the CPU 4 of the information device 1 through the communication interface 302.
A power failure detection signal is transmitted to 0. In addition, since the voltage of the DC input 300 decreases simultaneously with the occurrence of the power failure, the selector 34
The output of the built-in battery 31 is supplied to the information device 1 via the. The CPU 40 receives power supply from the built-in battery 31, activates a pre-installed evacuation program, and executes evacuation processing. This prevents abnormal operation of the information device 1 and loss of data. When the evacuation process ends,
The CPU 40 notifies the microcomputer 38 via the communication interface 302 of the end of the save processing.

The microcomputer 38 includes a CPU 40
After receiving the evacuation processing end notification from the terminal, the battery output control signal is transmitted from the Bo terminal to turn off the switch 35, the power supply from the built-in battery 31 is stopped, and the off signal is transmitted from the OFF terminal. Regulator 3
6 is turned off, and the power supply to the microcomputer 38 is stopped. As a result, the load on the built-in battery 31 during a power failure can be minimized.

When the power is restored from the power failure, the DC input 3
00 is supplied to the information device 1 via the selector 34.
When the power is restored, the RST of the microcomputer 38
A reset signal from the reset circuit 37 is input to the terminal, the microcomputer 38 is initialized, and a predetermined function is resumed and executed. Further, the remaining amount of the built-in battery 31 is detected from the input signal to the Bs terminal, and when the remaining amount has fallen below a predetermined value, a charge control signal is transmitted from the Cc terminal to the charging circuit 32. And built-in battery 3
1 is charged.

The DC / DC converter 39 shown in FIG.
Is for adjusting the output voltage of the AC adapter 2 in accordance with the required voltage of the information device 1, and is omitted when the output voltage of the AC adapter 2 is supplied to the information device 1 as it is. Even if this is omitted, the operation of the power supply device 30 is not changed.

In the above-described embodiment, the power supply source to the information device 1 is selected by the selector 34. However, instead of such a configuration, a switch device which is turned on and off by the microcomputer 38 may be provided.

Further, in the above embodiment, the AC adapter 2 is connected to the DC input 300 provided in the power supply device 30.
The DC output of the AC adapter 2 is connected to the DC input 200 provided in the information device 1 as shown in FIG. You can also do so.

In addition, in the above-described embodiment, the power supply device 30 is configured as a battery pack so that it can be detachably attached to the information device 1.
It is also possible to omit “a” and to incorporate it in a power supply unit of a required information device.

As shown in FIG. 3, a plurality of cells are connected only in series as the built-in battery 31, so that a discharge current capable of executing the evacuation process of the information device 1 is obtained, and the evacuation process of the information device 1 is performed. One having a capacity that can be executed a plurality of times is used. Conventionally, there is no small-sized and small-capacity battery capable of obtaining a large discharge current, and in order to execute the evacuation process of the information device 1, a large number of batteries are connected in series and in parallel as shown in FIG. Needed. However, with the recent technological advancement of secondary batteries, nickel-metal hydride batteries have been provided which are small and have a small capacity and can obtain a large discharge current, as indicated by reference numeral NN in FIG. By connecting a plurality of cells only in series, a built-in battery capable of executing the evacuation process of the information device 1 can be obtained, so that the number of cells to be used can be reduced, and the power supply device 30 can be reduced in weight and weight. Cost can be reduced.

The horizontal axis in FIG. 5 is the energy density corresponding to the battery capacity, and the vertical axis is the output density corresponding to the discharge current.
The symbol P in the figure is a lead battery, N is a conventional nickel-metal hydride battery,
L indicates the characteristics of a lithium-ion battery, and NN indicates the characteristics of a newly developed nickel-metal hydride battery. That is, the points plotted in the figure represent the characteristics of how much a certain amount of energy stored in the battery can be released, and the more the plot is located on the upper right side of the graph, the more the battery is plotted. It can be seen that the performance is high. Conventional nickel-metal hydride battery N
Has only lower performance than the lithium-ion battery L, but recently, a high-performance nickel-metal hydride battery indicated by reference numeral NN has been developed. This new nickel-metal hydride battery is called “5/3 AAA” and has about 10 times higher output characteristics than the conventional nickel-metal hydride battery. However, it is effective to be mounted on an information device having a much smaller load than an electric vehicle, and by using this battery, the evacuation process of the information device 1 can be performed by a plurality of batteries connected only in series. Power supply 3
0 can be realized.

In the secondary battery, the ratio of the discharge current Id to the capacity Ah is represented by the discharge rate C, and the capacity Ah (ampere
The discharge rate at which the hour is discharged in one hour is 1C. Now, the output voltage required for the power supply device 30, that is, the output voltage required for the information device 1 to execute the saving process is V ₀ , the output current required for the information device 1 to execute the saving process is I ₀ , Assuming that the discharge voltage of each cell is V, the capacity of each cell is Ah, the total operation time to guarantee is T, and the time required for the evacuation treatment is τ, the number of cells to be connected in series is n = V ₀ / V. . However, since n is an integer, the actual condition is n
≧ [V ₀ / V] (however, when [V ₀ / V] is not an integer, n is an integer immediately above it). Also, if designed to consume 1 / k of the power source capacitor total power _{supply, I 0 · T = Ah /} k, i.e., it is necessary capacity _{Ah = k · I 0 · T} . Further, in order to enable the evacuation processing more than m times, since T> m · τ, Ah> km
A capacity of I ₀ · τ (where k is a margin of cell capacity and satisfies k> 1 and m is a number of backup processes to be compensated and satisfies m ≧ 2) is required. On the other hand, as a condition of the discharge current, a cell having a discharge rate of C> Ah / I ₀ is required.

A new type nickel-metal hydride battery called “5/3 AAA” has V = 1.2 (V) and Ah = 1 (A
h), since C = 5, by connecting 10 cells in series, the margin k is set to 1.5 to 3, and V ₀ = 1
Electric power of 2 (V) and I ₀ = 5 (A) or more can be supplied for 10 minutes or more, and a notebook personal computer of about 40 to 60 (W) can be operated for 10 minutes or more. In addition, since the time τ required for the evacuation process of this type of personal computer is about three minutes, the power supply device having the above performance can execute the evacuation process three or more times.

Normally, that is, A
Information device 1 using DC converted from C input as operating power supply
When a power supply failure such as a power failure does not occur in the AC input, the power supply device 30 is a load only for self-discharge and a small amount of circuit operating power. If there is a power failure, the capacity of the built-in battery 31 decreases by the amount of processing performed during that time. The charging for the reduced amount is performed after the power is restored, but the charging is performed with a current smaller than the discharging current, so that the charging time is many times longer than the discharging time. Therefore, in a case where the power supply situation is not good, there is a possibility that a power failure occurs again during charging. Also in this case, the power supply device 30 of the present embodiment has a battery capacity capable of executing the evacuation process three times, so that it is possible to cope with the margin. Furthermore, it is extremely rare that power failures of three or more times occur at the same time, and it is considered that this will rarely occur practically. However, the power supply device 30 according to the present embodiment can cope with this state, and has excellent reliability. And practicality.

Next, a second embodiment of the power supply device according to the present invention will be described with reference to FIGS. FIG. 7 shows the second
FIG. 4 is a functional circuit diagram of the power supply device according to the embodiment, and FIG. 4 is a timing chart illustrating the operation of the power supply device according to the second embodiment.

In FIG. 7, reference numeral 1 denotes an information device such as a personal computer, reference numeral 30 denotes a power supply device according to the present embodiment, reference numerals 4 and 5 denote load devices of an AC power supply, and reference numerals 40 and 50 denote load devices 4 and 5. 2 illustrates a switch provided in an AC power supply path. As is clear from this figure, the power supply device 30 of the present embodiment uses the switch control signals a and b output from the microcomputer 38 to supply AC power to the load devices 4 and 5.
The input is integratedly controlled. Hereinafter, an operation and an effect of the power supply device 30 according to the present example will be described with reference to FIG.

Assuming that the power supply to a certain load device is started at time t0, the power is cut off at time T1 during operation, and the power is restored at time t2, a large starting current (rush current iR) is applied to the load device at the start of t0. Current) often flows. For example, when the power supply of the load device includes a transformer or a motor, or when the power supply is a power supply circuit of a capacitor input type, a rush current flows during normal startup. Assuming that the peak current at the time of startup is iR and the current value in a steady state is iS, the maximum ratio between iR and iS that can be supplied as a power supply device is called a crest factor, which is one index representing the performance of the power supply. I have.

As shown in FIG. 7, in an environment where the information device 1 and the load devices 4 and 5, which are peripheral devices, are connected to a public commercial power supply and these devices are started simultaneously, at the time of start-up and after a power failure. When the power is restored, an excessive current on which the starting current is superimposed flows. For this reason, in an environment where the power supply capacity is not sufficient, a voltage drop may occur, or in the worst case, a fuse may be blown or a breaker may operate to cause a second power failure. Therefore, in the present embodiment, a switch control signal delayed by a predetermined time from the input timing of the power supply from the microcomputer 38 is generated,
By integrally controlling the switches 40 and 50, the load devices 4,
5 is adjusted. As a result, the superposition of the respective starting currents can be reduced or prevented, and the occurrence of a new power failure such as a voltage drop or a second power failure can be prevented.

Next, a third embodiment of the power supply device according to the present invention will be described with reference to FIG. FIG. 9 is a configuration diagram of a power supply device according to the third embodiment.

As is apparent from this figure, the power supply device of this embodiment has a timing signal generation circuit 61 in the AC adapter 6.
The power switch 62 of the load device 4 built in the AC adapter 6 is controlled by a signal a generated from the timing signal generation circuit 61, and another load is controlled by a signal b generated by the timing signal generation circuit 61. The power switch 50 of the device 5 is controlled. With such a configuration, the same effect as that of the power supply device according to the second embodiment can be obtained.

Next, a fourth embodiment of the power supply device according to the present invention will be described with reference to FIG. FIG. 10 is a configuration diagram of a power supply device according to the fourth embodiment.

As is apparent from this figure, the power supply device of the present embodiment has an independent timing control function, and the timing signal generation circuit 2 uses the power supply of the AC adapter 2 as a reference.
0, the switch control signals a, b, c out of phase with each other
And the load devices 50, 70, and 80 are individually controlled by these switch control signals a, b, and c. With such a configuration, the same effect as that of the power supply device according to the second embodiment can be obtained. In addition, input,
The load may be either DC or AC. .

Next, a fifth embodiment of the power supply device according to the present invention will be described with reference to FIG. FIG. 11 is a configuration diagram of a power supply device according to the fifth embodiment.

As is apparent from this figure, the power supply device of the present embodiment is different from the power supply devices of the third and fourth embodiments in that a plurality of switch control units whose phases are shifted from the timing signal generation circuit are different from each other. In place of the configuration for generating a signal, for example, it is assumed that a plurality of switch devices S having delay means D for giving a required delay to the switch control signal a output from the microcomputer 38 in FIG. Features. With such a configuration, the same effect as that of the power supply device according to the second embodiment can be obtained.

[0049]

According to the first aspect of the present invention, since the information device has a built-in battery of the power supply device having a capacity that allows the information device to perform the evacuation process a plurality of times, even if a power failure occurs again after the power recovery, It can respond and is excellent in practicality and reliability. In addition, since a nickel-metal hydride battery connected only in series is used as the built-in battery, the number of cells can be reduced and the protection circuit can be simplified or omitted, and the power supply device can be reduced in weight and cost. it can.

According to the second aspect of the present invention, the communication interface between the power supply device and the information device is made compatible with the communication interface of the standard battery pack mounted on the information device. The power supply device of the present invention can be applied to the information device as it is, and the desktop use of the information device with the power supply device of the present invention mounted thereon and the portable use of the information device with the standard battery pack mounted are performed at any time. Therefore, the practicality and convenience of the information device can be improved.

According to a third aspect of the present invention, a power supply device includes a charging circuit for a nickel-metal hydride battery and a controller for the charging circuit, and discharges from the nickel-metal hydride battery and controls the controller itself according to a control signal output from the controller. Since the power supply is controlled, if the power failure of the AC power supply such as a power failure is expected to continue for a predetermined time exceeding the capacity of the internal battery, the internal battery is automatically discharged and the power to the controller is automatically Since the supply can be cut off, the load on the built-in battery can be minimized.

According to the fourth aspect of the present invention, the power supply of the peripheral device is integrally controlled on / off by the control signal output from the controller. Therefore, the start timings of the information device and the peripheral device are shifted by a predetermined time. It is possible to prevent an excessive start-up current from being superimposed at the time of start-up or power recovery, to prevent inconveniences such as a voltage drop and a power outage, and to improve the reliability of the power supply device. In addition, since the battery load can be reduced, it is not necessary to provide an excessive number of battery cells. In this regard, the backup power supply can be reduced in size, weight, and cost.

[Brief description of the drawings]

FIG. 1 is a block diagram of a power supply device according to a first embodiment.

FIG. 2 is a perspective view illustrating an appearance of a power supply device according to the first embodiment.

FIG. 3 is a functional circuit diagram of the power supply device according to the first embodiment.

FIG. 4 is a block diagram of a power supply unit of the information device equipped with the power supply device according to the first embodiment.

FIG. 5 is a graph showing characteristics of various batteries.

FIG. 6 is a block diagram of a power supply unit of the information device showing another mounting example of the power supply device according to the first embodiment.

FIG. 7 is a functional circuit diagram of a power supply device according to a second embodiment.

FIG. 8 is a timing chart for explaining the operation of the power supply device according to the second embodiment.

FIG. 9 is a configuration diagram of a power supply device according to a third embodiment.

FIG. 10 is a configuration diagram of a power supply device according to a fourth embodiment.

FIG. 11 is a configuration diagram of a power supply device according to a fifth embodiment.

FIG. 12 is a circuit diagram showing a configuration of a power supply system of a conventionally known small information device and a configuration of a battery pack applied thereto.

[Explanation of symbols]

 Reference Signs List 1 information device (load device) 2 AC adapter 3 AC input 10 internal power supply 20 selector 30 power supply device 31 built-in battery 32 charging circuit 33 controller 40 CPU 300 DC input 301 DC output 302 communication interface

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takashi Takeuchi 1-88 Ushitora, Ibaraki-shi, Osaka F-term in Hitachi Maxell, Ltd. (Reference) 5B011 DA06 DA07 DB04 JA04 5H030 AA04 AS03 AS11 BB01 BB21

Claims (4)

[Claims] 1. A power supply device having an internal battery for supplying operating power to an information device during an evacuation process, wherein the internal battery has an output voltage V ₀ required for the evacuation process and an output current required for the evacuation process. I ₀ , when the time required for one evacuation treatment is τ, the cell voltage is V, and the cell capacity is Ah, n ≧ [V ₀ / V] (provided that [V ₀ / V] is not an integer) , N is an integer immediately above it) and n cells are connected in series, and Ah> km · I · ₀ · τ (where k is a cell capacity margin ratio and satisfies k> 1) Value, m is the number of evacuation processes to be compensated, and m ≧
A value that satisfies 2. ) Becomes capacity and, C> Ah / I information device power supply apparatus characterized by a built-in nickel-hydrogen batteries having a ₀ becomes discharge rate. 2. The power supply device for an information device according to claim 1, wherein a communication interface with the information device is compatible with a communication interface of a standard battery pack mounted on the information device. . 3. The power supply device includes a charging circuit for the nickel-metal hydride battery and a controller for the charging circuit, and discharges the nickel-metal hydride battery and supplies power to the controller according to a control signal output from the controller. The power supply for an information device according to claim 1, wherein the power supply is controlled. 4. The power supply device includes a charging circuit for the nickel-metal hydride battery and a controller for the charging circuit, and controls a power supply of a peripheral device based on a control signal output from the controller. 2. The power supply device for an information device according to 1.