JPH10309044A - Backup power unit and its back-up method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a power unit and method for backing up a means to be backed up by which the discharging of a primary battery for backup can be maintained in the minimum state. SOLUTION: The charging voltage of a charging body which is connected in parallel with a primary battery 5 and composed of a secondary battery 3a or a capacitor 3b is selected higher than the reference voltage value of the primary battery 5 and, when the initial backup of a means 8 to be backed up is made, the means 8 is charged through the charging body 3a or 3b. Then, when the voltage of the charging body 3a or 3b reaches the prescribed reference potential of the primary battery 5, the supply of the backup voltage to the means 8 is automatically switched.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a memory, a clock and the like.
The present invention relates to a backup power supply device for backing up a C circuit and an improvement of a backup method.

[0002]

2. Description of the Related Art Conventionally, as a backup power supply device for backing up a means to be backed up such as a clock function and a memory in an electronic device when a power supply of the electronic device is interrupted, a primary power supply as shown in FIGS. 5A and 5B is used. A battery or a rechargeable secondary battery is used.

That is, the circuit diagram of FIG. 5A shows a case in which a primary battery 5 is used, and a backup means 8 such as an IC having a memory and a clock function is connected via a switch 10 between input terminals T ₁ and T _2. , The anode of diode 2 for preventing charging and 1
The anode of the next battery is connected in series,
The cathode side of the diode 2 and the cathode side of the primary battery 5 are connected in parallel.

FIG. 5B shows a case where a secondary battery 3a is used. A backup means 8 is connected between the input terminals T ₁ and T ₂ via a switch 10, and an anode of a diode for preventing overcharging is connected to the charging terminal. The possible anode of the secondary battery 3a is connected in series, the cathode of the diode 2 and the cathode of the secondary battery 3a are connected in parallel to both ends of the backup means 8, and the charger 1 is connected in parallel to both ends of the diode 2. I have. At the time of charging, a predetermined voltage is applied to the input terminals T ₁ and T ₂ to charge the secondary battery 3a.

In the event of a power failure, the switch 10 is turned on to supply a voltage to the backed-up means 8 from the primary battery 5 or the secondary battery 3a.

[0006]

A primary battery as shown in FIG. 5A is often used as the backup power supply having the above-described configuration. In this case, however, the primary battery itself has a small capacity, so that it takes a long time. There was a problem that it was not possible to make a backup. In addition, when a secondary battery as shown in FIG. 5B is used, it is necessary to always charge the secondary battery via a charger, and it is necessary to save much time for monitoring the state of charge.

An object of the present invention is to provide a backup power supply apparatus and a backup power supply backup method which solve the above-mentioned problems, and an object thereof is to combine a primary battery and a secondary battery for a long time. An object of the present invention is to provide a backup power supply device capable of withstanding a backup and a backup power supply backup method.

[0008]

As shown in FIG. 1, a backup power supply according to the present invention is a backup power supply for backing up a means to be backed up 8 through a primary battery 5. A power supply device 9 connected in parallel to the primary battery 5 and connected to the primary battery 5 via a charging input power supply unit;
It has chargers 3a and 3b configured to be charged to a voltage higher than the secondary battery voltage. The backup unit 8 is backed up via the charging units 3a and 3b during the initial backup operation, and the primary battery is used during long-term backup. 5, the backup means 8 is backed up.

According to the present invention, in the initial stage of the backup, the backed-up means 8 is backed up using a charging means such as the secondary battery 3a, and after the charging means has discharged for a predetermined time, the discharge voltage is detected, and Switch to the primary battery 5
As a result, the backup means 8 is backed up, so that a backup power supply device and a backup power supply backup method capable of reducing the discharge amount of the primary battery and extending the life can be obtained.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A backup power supply and a backup power supply backup method according to the present invention will be described below in detail with reference to FIGS.

Referring to FIG. 1, input terminals T ₁ and T ₂
Is connected to a charging power supply. An electronic circuit including a clock function or a memory such as a RAM, that is, a backed-up means 8 is connected between the input terminals T ₁ and T ₂ via a switch 10 which is turned on during a power failure. .

As the charger 1, a serial charging type or a parallel charging type is known. FIG. 1 shows a configuration in which the charger 1 is connected in parallel to input terminals T ₁ and T ₂ . Charger 1 is 2
A charged body such as the secondary battery 3a or the capacitor 3b having a large capacity is charged.

The charger 3a or 3b is connected in series with the overcharge preventing diode 2 as in FIG. 5B, and this series circuit is connected in parallel between the input terminals T ₁ and T ₂ . Further, the primary battery 5 has an anode connected to one end of the switch 6.
The series circuit of the secondary battery 5 and the switch 6 is connected to the charger 3a or 3b.
And a detector 4 for detecting the voltage between both ends of the charger 3a or 3b is connected in parallel to the chargers 3a and 3b, a detection output of the detector 4 is supplied to the control circuit 7, and the switch 6 and the charger 1 is controlled.

The operation of the above configuration will be described. now,
When the switch 10 is turned on, the charging voltage of the charger 3a or 3b monitored by the detector 4 so as to be always maintained in the charged state is equal to the primary battery as shown in the characteristic diagram of FIG. 5 of the reference voltages V ₁ than ΔV only in the initial state so placed in the manner set slightly higher the backup unit 8
Automatically supply backup voltage to That is, the discharge characteristic curve lines in FIG. 2, taken the discharge time a voltage on the vertical axis on the horizontal axis (H), curve 13 is the voltage of the primary battery 5 - shows the discharge characteristics, selected on the basis voltages V ₁ Have been. Secondary battery 3a
In selecting as the reference voltages V ₁ than ΔV as high curve 11 Figure 2 1 battery 5. Further, the discharge voltage may have a characteristic such that the discharge voltage rapidly drops from the charge voltage V ₂ > V ₁ as shown by a curve 12 in FIG. 2, like the capacitor 3b.

The primary battery 5 and the charger 3a having such characteristics
Since or 3b time to back up according to the combination of the case relatively short is large, the charging member 3a or back up the backup means 8 by the charging voltage of 3b, the detector 4 after a predetermined time T ₁ is charged bodies 3a Alternatively, the control circuit 7 detects that the voltage of 3b has decreased by ΔV, turns on the switch 6 via the control circuit 7, and performs control to start charging the charger 1.

If the above control is performed, the charger 3a or 3
Since the backup means 8 is backed up by the primary battery 5 from the point of time when the backup of b is completed, consumption of the discharge voltage of the primary battery is suppressed, and a backup power supply device and a backup power supply that can back up for a long time Backup method can be provided.

In the configuration of FIG. 1, a switch 6 connected in series to the 1 o'clock battery 5 is controlled based on the detection output of the detector 4, but the switch is not provided as shown in FIG. You can do it.

In FIG. 3, the primary battery 5 and the secondary battery 3a or the capacitor 3b are connected in parallel, and the charging voltage of the charged body composed of the secondary battery 3a or the capacitor 3b is changed to the charging voltage V as shown by the characteristic 12 in FIG. if taking high _2, charging member 3a discharge voltage at the moment the switch 10 is "on" when the power charging member 3a or 3b side to the backup unit 8 or 3
b → diode 2 → switch 10 → backed-up means 8 → voltage is automatically supplied through the path of the charger 3a or 3b, and further, the charging voltage of the charger 3a or 3b drops by discharging, and the primary battery 5 Automatically reaches the backup reference means 8 via the primary battery 5 when the average reference voltage value reaches
The backup voltage is supplied through the path of the primary battery 5 → diode 2 → switch 10 → backed-up means 8 → primary battery 5.

Therefore, the voltage drop of the charger 3a or 3b can be detected by the detector 4 and the charging of the charger 1 can be controlled to start. In this case, a primary battery 5 and a secondary battery 3a or a capacitor 3b connected in parallel are integrally laminated as shown in FIG. 4 to reduce the size, thereby providing a backup power supply device suitable for portable electronic devices and the like. Can be obtained.

[0020]

According to the backup power supply device and the backup power supply backup method of the present invention, a combination of a primary battery and a charger such as a secondary battery is used.
The consumption of the discharge voltage of the secondary battery is suppressed, and one
The secondary battery can be used, and a long-life backup power supply can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a backup power supply device of the present invention.

FIG. 2 is an explanatory diagram of characteristics of a battery used in the backup power supply device of the present invention.

FIG. 3 is another circuit diagram of the backup power supply device of the present invention.

FIG. 4 is a configuration diagram of an example of a backup power supply device of the present invention.

FIG. 5 is a circuit diagram of a conventional backup power supply device.

[Explanation of symbols]

1 charger, 2 diode, 3a secondary battery, 3b
Capacitor, 4 detector, 5 primary battery, 6, 10 switch, 7 control circuit, 8 means to be backed up

Claims (4)

[Claims] 1. A backup power supply device for backing up a device to be backed up through a primary battery, wherein the backup power supply device is connected in parallel to the primary battery and is connected to the primary battery through a charging input power supply unit. A charging unit configured to be charged to a voltage higher than the battery voltage; a backup unit that is backed up through the charging unit during the initial backup operation; and a primary battery during the long-term backup operation. A backup power supply characterized in that the backup means is backed up. 2. A detecting means for detecting a charging voltage at both ends of the charger and a switching means connected in series to the primary battery, wherein the switching means is controlled based on a detection output of the detecting means. 2. The backup power supply according to claim 1, wherein: 3. A charging device according to claim 1, further comprising detecting means for detecting a charging voltage at both ends of said charging body, wherein said charging input power supply is controlled based on a detection output of said detecting means. Backup power supply. 4. A backup method for backing up a device to be backed up through a primary battery, wherein a voltage of a charged body connected in parallel to the primary battery and charged from a charging input power supply. Is higher than the voltage of the primary battery, the voltage between both ends of the charged body is detected, and based on the detected output, the backup means is initially backed up by the charged body, and the detected output is used as the primary battery. A backup method for backing up the means to be backed up from a primary battery when the upper limit potential is reached.