JPH0328897B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is a power source for various electrical equipment that uses commercial power for normal operation and that needs to continue its operation with a secondary battery such as a battery in the event of a commercial power failure. This relates to a backup device.

1. Configuration of a conventional example and its problems FIG. 1 is a schematic configuration diagram of a conventional backup device. In Fig. 1, 1 is a rectifier circuit that rectifies the commercial power supply, 2 is a constant voltage circuit that makes the power supply rectified by the rectifier circuit 1 constant, and 3 is a rechargeable secondary battery, which is commercially available. When the power source is in use, it is configured to be constantly charged by a charging circuit consisting of a diode D and a current limiting resistor R.
4 is a power failure detection circuit; 5 is a switching control circuit that controls a relay contact a for switching between two power sources, a commercial power source and a battery; the circuit is controlled by a power failure detection signal from the power failure detection circuit 4. It is configured as follows. That is, when the commercial power source is used, the relay contact a is on the commercial power source side, and only when a power outage occurs, the switching control circuit 5 is activated by the signal detection signal from the power failure detection circuit 4, and switches the relay contact a to the battery side. Therefore, in this state, the switching control circuit 5 continues its operation using the voltage of the battery 3. Further, SW is a power switch that turns on and off the commercial power supply and the secondary battery 3 at the same time, and when this power switch SW is turned off, the commercial power supply and the secondary battery 3 are turned on and off at the same time.
The secondary batteries are separated from each other to prevent unnecessary backup.

However, such conventional backup devices have one major drawback. When the power switch SW is turned off, there is no need for unnecessary backup as explained above, but unlike in ordinary offices and factories, the main power supply is switched off for each floor or room. If the power is turned off, there is no way to distinguish between this and a power outage, so the battery will continue to perform backup operations until the battery is completely depleted.Therefore, it will take some time before the battery is fully charged the next time the power is turned on. The problem was that it took a considerable amount of time, and if there was a power outage before then, the operation could not be guaranteed until the originally designed backup time.
Particularly, in places where the power is turned on and off every day, complete charging and complete discharging are repeated every day, which has no positive effect on the life of the battery.

Purpose of the Invention The purpose of the present invention is to eliminate the drawbacks of the above-mentioned conventional example, and to provide an excellent backup device that can eliminate unnecessary battery consumption and guarantee backup time as designed when it is actually required. That is.

Structure of the Invention In order to achieve the above object, the present invention divides backup by a secondary battery into two stages.In the first stage, backup is carried out for a certain minimum necessary period of time, and in the second stage, backup is carried out for the above-mentioned certain period of time. Regardless, the configuration is such that backup can be performed for a certain period of time determined by the capacity of the secondary battery.

DESCRIPTION OF EMBODIMENTS The structure of an embodiment of the present invention will be described below. FIG. 2 is a schematic configuration diagram of an embodiment of the present invention, in which 6 is a rectifier circuit that rectifies the commercial power supply, and 7 is a constant voltage circuit that makes the voltage rectified by the rectifier circuit 6 constant. , 8 is a rechargeable secondary battery,
9 is a power outage detection circuit that monitors commercial power outages; 1
Reference numeral 0 denotes a power supply switching control circuit that operates in response to a power failure detection signal from the power failure detection circuit 9, and 11 a timer circuit for terminating the operation of the power supply switching control circuit 10 at a fixed time.

Next, the operation of the above embodiment will be explained.

While the commercial power supply is normal, the relay contact a for power switching is connected to the commercial power supply side, and the power is connected through the path of the commercial power supply, power switch SW ₁ , rectifier circuit 6, relay contact a, and constant voltage circuit 7. is supplied. Here, when the commercial power supply is in a power outage state, the power outage detection circuit 9 first detects this, and the power supply switching control circuit 10 closes the relay contact a to the battery side. That is, the power supply switching control circuit 10 utilizes the charge in the capacitor that has been charged when the commercial power supply is used to close the relay contact a to the battery side as soon as it receives the signal from the power failure detection circuit 9.
The power switch SW ₁ is on when commercial power is used, so when the commercial power fails and the relay contact a is turned on to the battery side, the voltage from the secondary battery 8 is applied to the switch SW ₁ and the relay contact a, constant voltage circuit 7
The power supply switching control circuit 10 also continues its operation using the voltage of the battery 8, and maintains the state in which the relay contact a is connected to the battery side. switch here
When SW ₂ is on, the switch is activated after a predetermined period of time by the output of the timer circuit 11 which is activated by the power failure detection signal from the power failure detection circuit 9.
The operation of the power supply switching control circuit 10 is forcibly canceled through SW ₂ . Therefore, in this case, the relay contact a is restored after the above-mentioned certain period of time, and the battery is prevented from being discharged more than necessary. While the timer circuit 11 is in operation, its output is used as an ALM signal.
It is applied to an alarm circuit, etc. to warn the outside that the battery will be disconnected after a certain amount of time. In this way, if the user of the system still wishes to continue operation during the alarm, by turning off the switch SW ₂ , the power supply switching control circuit 10 is switched off from the battery regardless of the timer signal from the timer circuit 11. The battery voltage can be output to the output terminal until the life of the battery. The switch SW ₂ is configured so that the operator can operate it at will, so if a long backup is required in advance, the switch SW 2 can be operated at will.
You can also turn SW ₂ off from the beginning. Further, the power switch SW ₁ is configured to be able to turn on and off the commercial power source and the battery 8 at the same time, and when turned off, the battery backup can be disconnected as in the conventional case.

Effects of the Invention As is clear from the above embodiments, the present invention is configured such that backup by a battery can be limited to a predetermined period of time using a timer circuit. When a certain period of time is limited, unnecessary consumption of the battery can be prevented, and over-discharge of the battery can be prevented, thereby significantly extending the life of the battery. According to the present invention, the control by the timer circuit can be canceled arbitrarily, and therefore, when necessary, the control by the timer circuit can be arbitrarily set for a sufficient period of time, regardless of the predetermined period of time. Backup time can be realized. In particular, in this case, even if a backup is performed using a timer circuit, a warning is issued before the backup ends, so the mode can be switched by listening to the warning, and the backup will not be interrupted midway. This has the advantage that it can be easily prevented from occurring.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a conventional power backup device, and FIG. 2 is a schematic diagram of an embodiment of the power backup device of the present invention. 6... Rectifier circuit, 7... Constant current circuit, 8... Secondary battery, 9... Power outage detection circuit, 10... Power supply switching control circuit, 11... Timer circuit, SW ₁ , SW ₂ ... Switch, a... Relay contact.

Claims (1)

[Claims] 1 A rechargeable secondary battery for backup, a charging circuit that charges this battery when using commercial power,
a power outage detection circuit that detects a power outage in the commercial power supply; a first switching circuit that automatically switches the power supply source from the commercial power supply side to the battery side by the operation of the power outage detection circuit; a timer circuit that continues the operation of the first switching circuit for a predetermined period of time; and when the first switching circuit is operated by the timer circuit, when the predetermined period of time approaches arbitrarily disconnect the means for issuing an alarm and the timer circuit,
A second switching circuit is provided for keeping the first switching circuit in operation irrespective of a predetermined period of time determined by the timer circuit, and backup in the event of a power outage is limited by the timer circuit. A power backup device characterized in that it has two backup modes: a first stage in which the power supply is switched by the second switching circuit, and a second stage in which the limitations imposed by the timer circuit are removed by switching the second switching circuit.