JPH10322897A - Power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption by supplying power externally to charge a secondary battery up to a second preset level when the voltage of the secondary battery drops below a first preset level. SOLUTION: A waiting power supply 20 supplying a power required for sustaining the state of an information processor 5 by converting an input voltage into an output voltage is provided with a secondary battery and a monitor means 22 for comparing the voltage of the waiting power supply 20 with a first preset level is provided with a switch 21 for switching a path passing through the waiting power supply 20 depending on the comparison results. The switch 21 is turned off if the voltage of the waiting power supply 20 is higher than the first preset level otherwise the switch 21 is turned on to charge the secondary battery up to a second preset voltage. According to the arrangement, waste of power can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply provided in an apparatus requiring a standby power supply. For example, the present invention relates to power supplies for various devices ranging from a facsimile, a VTR, a boombox, and information processing equipment such as a copying machine and a computer.

[0002]

2. Description of the Related Art As a prior art, Japanese Patent Application Laid-Open No. 7-298488
Has been proposed.

[0003] This is as follows.

As for the power supply device with a power saving function, in FIG. 6, a main power supply means 110 for converting an input voltage into a predetermined output voltage and supplying sufficient power for the operation of the information processing device 105, Sub-power supply means 20 for converting the voltage into voltage and supplying power necessary for maintaining the state of information processing apparatus 105, and state monitoring means for monitoring the use state of information processing apparatus 105 and outputting use state information indicating the use state 1
12 and the main power supply means 11
Switch 111 for opening and closing a path for supplying an input voltage to 0
And

For this reason, the power is supplied to the sub power supply even during standby.

[0006]

In the conventional power supply device with a power saving function, power is always supplied to the sub-power supply for supplying power to the memory, and the energy is always discarded only for the loss of the conversion efficiency. Power consumption is increased.

[0007] In various home appliances, while energy saving is progressing,
The problem is that the standby power is still as large as 1/4 to 1/3 of that during normal use.

[0008]

According to a first aspect of the present invention, there is provided a power supply device including a secondary battery serving as a standby power source and a circuit for monitoring the secondary battery voltage, wherein the first secondary battery voltage is predetermined.
The power supply device supplies power from the outside so that the battery is charged until the secondary battery voltage becomes equal to or higher than a second predetermined value when the voltage becomes equal to or lower than the predetermined value.

According to a second aspect of the present invention, there is provided a power supply device including a capacitor as a standby power source and a circuit for monitoring a voltage between both ends of the capacitor. A power supply device for supplying electric power from outside so as to charge until a voltage between both ends of a capacitor becomes equal to or more than a second predetermined value.

According to a third aspect of the present invention, when the secondary battery voltage falls below a first predetermined value, the secondary battery is charged for a certain period of time. Power supply device for supplying electric power from the outside in such a manner as to perform the power supply.

According to a fourth aspect of the present invention, in the power supply device of the second aspect, when the voltage between both ends of the capacitor becomes equal to or less than a first predetermined value, the capacitor is charged for a predetermined time. A power supply device for supplying electric power from the outside.

According to a fifth aspect of the present invention, in the power supply device, the power supply is turned on only when the secondary battery or the capacitor is charged for the purpose of supplying power from the outside in a standby state of the device.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

A power supply control method is proposed in which a switch is also provided in front of the sub power supply, and in standby mode, power can be supplied without supplying power to the sub power supply.

FIG. 1 is a block diagram showing the principle of a power supply device of a standby power saving type according to the present invention.

According to the first and fifth aspects of the present invention, the main power supply means 10 for converting an input voltage into a predetermined output voltage and supplying sufficient power for the operation of the information processing device 5, and a use state of the information processing device 5. , A switch 11 for opening and closing a path for supplying an input voltage to the main power supply means 10 in accordance with the contents of the use state information, and an information processing device 5 which converts the input voltage to an output voltage to convert the input voltage to an output voltage. The auxiliary power supply means (standby power supply) 20 for supplying the power required to maintain the state of
A switch for providing a secondary battery to the standby power supply 20 to be charged and for opening and closing a path via the standby power supply 20 depending on the magnitude of the comparison monitoring means 22 for comparing the voltage of the standby power supply 20 with a first specified value. (If the voltage of the standby power supply 20 is higher than the first specified value, the switch 21 is turned off to save power and reduce the voltage of the standby power supply 20 to the first specified value. If the value is smaller than or equal to, the switch 21 is turned on, and charging is performed until the value becomes equal to or more than the second specified value.

Claim 2 is also a principle block diagram of the standby power saving type power supply device of FIG.
By providing a large-capacity capacitor in the standby power supply 20, a switch 21 that opens and closes a path via the standby power supply 20 is provided, thereby realizing energy saving.

Also, in the principle block of the standby power saving type power supply device of FIG. 1, the voltage of the standby power supply 20 is reduced by the comparison monitoring means 22 by utilizing the time constant of the capacitor and the resistor. If the value is equal to or smaller than the specified value of 1, the standby power supply 20 is charged for a specific time (the fourth solution is the same as the second solution).

According to the first and fifth aspects of the present invention, the switch 21 operates according to the state of the sub power supply means (standby power supply) 20 determined by the comparison monitoring means 22 in FIG. The power supply itself to the standby power supply 20 can be cut off, and the operation can be restarted when the standby state is released.

On the other hand, the switch 11 mainly operates on the main power supply means 10. However, if the switch 11 is operated only on the main power supply means 10, there is no power supply to the standby power supply 20 first. Since the above work does not make sense,
The standby power supply 20 is configured as a switch that works in conjunction with a switch to the main power supply means 10 so that power is also supplied to the standby power supply 20.

The secondary battery B ₁ of the standby power supply 20 can be represented by an equivalent circuit as shown in FIG.

According to the second aspect of the present invention, the standby power supply
Mass capacitor C ₂ 0 are expressed by an equivalent circuit as shown in FIG.

According to the third and fourth aspects of the present invention, power is supplied to the standby power supply 20 for a specific time by the comparison monitoring means 22 of FIG.

FIG. 2 is a block diagram showing an embodiment of the power supply of standby power saving specification of the present invention.

In FIG. 2, the power supply with standby power saving function according to claim 1 is a conventional power supply device with a power saving function shown in FIG. 6 which includes a secondary battery provided in a sub power supply (standby power supply) 20 and an input power supply. Switch S1 for opening and closing the path to standby power supply 20
And switches S21 and S22 linked to each of the main power supply 10 and the standby power supply 20, and a comparison monitoring circuit 22 for comparing and monitoring the voltage of the standby power supply 20.

When the switches S21 and S22 are turned on for the first time, the main power supply 10 and the standby power supply 20 are turned on.
When the standby power supply 20 is charged and the power supply is turned on for the second and subsequent times, the standby power supply 20 operates as a switch that opens and closes the path to only the main power supply 10.

The comparison monitoring circuit 22 is a circuit for comparing and monitoring the charged voltage of the standby power supply 20. If the voltage of the standby power supply 20 becomes lower than the first specified value (eg, 2.5 V), the operation starts from OP1. Set in FF1 and switch S
1 is turned on to charge the standby power supply 20, and the voltage of the standby power supply 20 is set to a second specified value (eg, 4.5V).
If it becomes the above, enter FF1 from OP2 and RESET
Then, the switch S1 is turned off, and the operation is performed so as not to waste electricity by not conducting to the standby power supply 20.

In FIG. 2, the switch S1 is operated by a relay, but the relay can be realized by a power FET because it uses electric power.

Next, a description will be given of a power supply with a reduced standby power consumption according to a second aspect of the present invention.

The same operation as that of the first embodiment is realized by providing a large-capacity capacitor in the standby power supply 20 in FIG.

In the case of a secondary battery, the holding time is long, but in the case of a large capacity capacitor, the holding time is often shorter (depending on the energy holding density).

In the former case, the cost is slightly higher,
The latter requires more recharging.

Next, a power supply of standby power saving specification of claim 3 will be described.

The power supply with standby power saving specification according to the third aspect is described with reference to the switches S21 and S22 in the time chart of FIG.
In first after ON, the switch S1 is ON at R / S output of FF1, the series of flow switch S1 is over OFF, adjust the value of C ₁ comparison monitoring circuit 22 (FIG. 2), the optimum Time constant t, and this time constant t (= C ₁ ×
Using R), the FF 1 operates to charge the standby power supply 20 during the ON time of the switch S1 of the R / S output.

The necessity of this time (C ₁ × R) is shown in FIG.
As shown in FIG. 5, a secondary battery or a large-capacity capacitor has a charging time delay shown in an equivalent circuit corresponding to the internal resistance during charging, and is provided to compensate for it.

For this reason, it may not be sufficient to just look at the upper / lower limit voltage in the comparison monitoring circuit 22, and monitoring can be ensured by monitoring the charging time with the time constant t.

However, if a margin is set for the upper limit of the voltage or a margin is set for the time constant t, it is possible to perform monitoring only by voltage or time without monitoring both. Next, the power supply of standby power saving specification of claim 4 will be described.

The same operation as that of the third embodiment is realized by providing a large-capacity capacitor in the standby power supply 20 in FIG.

Next, a power supply of standby power saving specification of claim 5 will be described.

The standby power supply with reduced power consumption according to the fifth aspect also overlaps the description of the first aspect, but in FIG.
The switches S21 and S22 are turned on for the first time, and
0, the power is turned on to the standby power supply 20, and the power is once stored in the standby power supply 20. In the second and subsequent power-on operations, the power supply operates as a switch that opens and closes the path to only the main power supply 10. About the comparison monitoring circuit 22
Switch S1 is opened and closed, and the switch S1 is turned ON only when the voltage of the standby power supply 20 falls below the first specified value.
N, and operates so that the standby power supply 20 is recharged.

[0041] Finally, when combined will be described in light of the structural diagram of Figure 2 the operation of the time chart of FIG. 3, t ₁ at the time of turning ON the switch S21, S22, t ₃ o'clock turned OFF,
The output voltage V of the sub-power supply (standby power) 20 in time t ₁ until t _3, and outputs a voltage of a certain value, t ₄ begins to at standby power 20 discharge, the t ₅ at V _R (V With the voltage divided by R ₁ and R ₂ , the voltage at t ₂ (= output from time t ₁ + C ₁ × R ₂ ) becomes lower than the voltage V ₁ and enters FF1 from OP1 and S
It is ET, and ON the switch S1, t ₆ at standby power 2
0 begins to charge a high voltage at t ₇ V _R is higher than V ₂ voltage, enters the OP2 from FF1, the RESET, OFF the switches S1, cut off the power supply to the standby power supply 20, waits at t ₈ power 20 is again discharged, t starting at less t ₄
Repeat the flow until ₈ o'clock.

[0042]

According to the present invention, by operating the switch according to the state of the standby power supply, the standby state is set.
No power is supplied to the standby power supply, and when the standby state is released, the power supply can be resumed.Therefore, the necessary minimum power is supplied to the standby power supply, eliminating unnecessary power consumption and reducing power consumption. Can be reduced.

Specifically, in FIG. 3, S1 is OFF.
When the time t _a, S1 is the time ON and t _b, the conventional (t _a + t _b) of the time it takes to standby power, the present invention is t
_Since only _b is used, no electric power can be used for a time of t _a / (t _a + t _b ), and waste of energy can be eliminated.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the principle of a power source using reduced standby power according to the present invention.

FIG. 2 is a configuration diagram of an embodiment of a power supply using standby power saving according to the present invention.

FIG. 3 is a time chart in the configuration diagram of FIG. 2;

FIG. 4 is an equivalent circuit of the sub power supply of FIG. 2 (in the case of a secondary battery).

FIG. 5 is an equivalent circuit of the sub power supply in FIG. 2 (in the case of a large-capacity capacitor).

FIG. 6 is a diagram illustrating a configuration example of a conventional power supply device with a power saving function.

[Explanation of symbols]

Reference Signs List 5 information processing device 10 main power supply means 11, 21 switch 12 state monitoring means 20 sub power supply means (standby power supply) 22 comparison monitoring means 10 main power supply 20 sub power supply (standby power supply) 22 comparison monitoring circuit S21, S22, S1 switch FF1 flipflop OP1, OP2 operational amplifier B ₁ secondary battery C _1, C ₂ capacitors _{R 1, R 2, R M} , R N resistors _{V, V 1, V 2,} V R voltage _{t 1, t 2, t 3} , _{t 4, t 5, t 6} , t 7, t 8 hours (time) t _a, t _b the time interval DC / DC converter

Claims (5)

[Claims] A secondary battery serving as a standby power source and a circuit for monitoring the secondary battery voltage are provided, and when the secondary battery voltage falls below a predetermined first predetermined value, the secondary battery is recharged. A power supply device for supplying electric power from outside so as to charge the battery until the battery voltage becomes equal to or higher than a second predetermined value. 2. A capacitor as a standby power source and a circuit for monitoring the voltage between both ends of the capacitor are provided, and when the voltage between both ends of the capacitor falls below a predetermined first predetermined value, the voltage between both ends of the capacitor is set in advance. A power supply device for supplying electric power from the outside so as to charge the battery until the voltage becomes equal to or more than a predetermined second prescribed value. 3. The power supply device according to claim 1, wherein when the secondary battery voltage becomes equal to or less than a predetermined first predetermined value, external power is supplied so as to charge the secondary battery for a predetermined time. A power supply characterized by supplying. 4. The power supply device according to claim 2, wherein when the voltage between both ends of the capacitor becomes equal to or less than a first predetermined value, power is supplied from outside so as to charge the capacitor for a certain period of time. A power supply device characterized by the above-mentioned. 5. A power supply device in which a power supply is turned on only when a secondary battery or a capacitor is charged for the purpose of supplying power from the outside in a standby state of the device.