JPS62250832A - Source feeder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a power supply device that supplies power using a battery as an alternative during a commercial power outage.

2. Description of the Related Art In recent years, many computer devices using commercial power sources have been used in important areas of social life. In particular, when a power outage occurs in hospitals' medical systems and electronic exchanges, many people are seriously affected. For this reason, various types of power supply devices have been developed as backup power supplies in case of power outages.

Hereinafter, the conventional υ bow source supply device as described above will be explained with reference to the drawings.

No. 3L4 shows a block diagram of a conventional power supply device. In Figure 3, 1 is a power failure detection circuit that detects the voltage of the commercial power supply and detects the occurrence of a power outage of the commercial power supply, and 2 is a power failure detection circuit that detects the battery voltage and further prevents over-discharge. 3 is a power supply switching circuit that switches between battery voltage output and commercial power supply; 4 is a switching control circuit that controls the operation of power supply switching circuit 3; 6 is a battery, and 6 is a voltage conversion circuit that converts the voltage of the battery 5 into a voltage equal to the voltage supplied from the commercial power source.

The operation of the power supply device configured as described above will be described below.

When the commercial power supply fails, the power failure detection circuit 1 detects the power failure and outputs a detection signal to the switching control circuit 4.

Next, the switching control circuit 4 receives an identification signal from the battery voltage detection circuit 2 indicating whether the battery voltage can be supplied to the load (the battery voltage is above a predetermined value), and if it can be supplied, operates the power supply switching circuit 3. , the voltage of the battery 5 is converted by a voltage conversion circuit 6 to a voltage equal to that of a commercial power source, and is supplied to the load.

Problems to be Solved by the Invention However, with the above-described configuration, if the load fluctuates greatly or the load is large, the electric IT! 15 also fluctuated greatly, which caused the problem that the battery voltage detection circuit 2 malfunctioned.

Hereinafter, the state and complexity of the malfunction will be explained with reference to FIG. 4 together with FIG. 3. In the graph of the fourth factor, the vertical axis shows the battery voltage, and the horizontal axis shows the passage of time. Moreover, the curve in the graph shows the change in battery voltage over time.

The supply start point is shown at point A in FIG. At the start of supply (point A), the battery voltage is high, but as time passes, the electricity ith 5 is discharged and the battery voltage gradually decreases. If the load is heavy, the battery voltage will drop more rapidly. Point B in FIG. 4 is the point at which the battery voltage has dropped to the point where it is no longer possible to supply power to the load. Switching control circuit 4 at point B
In order to prevent battery 5 from over-discharging, the output from battery 5 is cut off.

However, when the load is disconnected, the battery voltage rises rapidly and returns to a supply voltage again, connecting the output from the battery to the load. This resupply point is indicated by point 0 in FIG. However, since the capacity of the battery 5 is low, the battery voltage immediately drops and the supply stops. This stopping point is indicated by point D in FIG. Thereafter, the state at point 13-D in FIG. 4 is repeated until the battery voltage drops completely. In other words, the supply circuit enters a kind of oscillation state.

Conventionally, as a measure to prevent the supply circuit from oscillating, a hysteresis characteristic has been added to the detection characteristics of the battery voltage detection circuit 2 to prevent the supply operation from becoming unstable even if the battery voltage fluctuates to some extent. However, if the amount of variation in battery voltage due to load variation deviates from a predetermined hysteresis width, the supply circuit will still be in an oscillating state. Therefore, it has been desired to develop a device that can supply stable power even when the load fluctuates.

The present invention has been made in view of the above-mentioned prior art, and it is an object of the present invention to provide a power supply device that can stably supply power without being affected by changes in battery voltage due to changes in load.

Means for solving the problem In order to achieve this purpose, the power supply device of the present invention is mainly used.
a first voltage detection means for detecting power outage/restoration of 11 sources;
It has an auxiliary power supply that supplies power to the load during a main power outage, and switches to the auxiliary power supply when the main power supply fails, and when the auxiliary power supply is connected to the load and the voltage of the auxiliary power supply drops, the auxiliary power supply is switched off from the load. The control means disconnects the load, maintains the disconnection even if the voltage of the auxiliary power source increases in this state, and connects the main power source and the load when the main power source is restored.

Effect: With this configuration, even if the voltage of a dynamic power source such as a battery fluctuates due to a sudden change in load, the operation of the power supply switching circuit is latched and a stable power supply is provided.

Embodiment Hereinafter, an embodiment of the invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a first embodiment of the power supply device of the present invention. In Fig. 1, 11 is a power failure detection circuit;
12 is a battery voltage detection circuit that detects the voltage of the battery; 13 is a power supply switching circuit; 14 is a switching control circuit that controls the power supply switching circuit 13; 15 is a battery; 16 is a voltage conversion circuit; 17 is a switching control circuit 14; Latch circuit that latches operation, 18
is a latch release circuit that releases the operation of the latch circuit 17.

The battery 15 is connected to a battery voltage detection circuit 12, and the output of the battery voltage detection circuit 12 is connected to a voltage conversion circuit 16, a switching control circuit 14, and a latch release circuit 18. Further, the outputs of the switching control circuit 14 and the latch release circuit 18 are connected to the latch circuit 17. Power outage detection circuit 1
The output of 1 is connected to the latch release circuit 18 and the switching control circuit 14. A commercial power supply is connected to the power supply switching circuit 13, and the outputs of a voltage conversion circuit 16 and a latch circuit 17 are also connected to the power supply switching circuit 13.

The operation of the power supply device configured as described above will be described below. When the commercial power supply stops, the power outage detection circuit 11 detects the power outage. Next, the switching control circuit 13
A determination signal is received from the battery voltage detection circuit 12 as to whether or not the battery voltage can be supplied to the load, and if the battery voltage can be supplied, the power supply switching circuit 13 is operated. Next, the switching control circuit 14 lags the operation of the power supply switching circuit 13. Therefore, even if the battery voltage fluctuates due to sudden changes in load, it is possible to provide stable power supply. Also, if commercial power is restored,
The power failure detection circuit 11 operates the latch release circuit 18 together with the switching control circuit 14, and the power supply switching circuit 14 connects the load to the commercial power source. When the battery voltage drops and cannot be supplied to the load, the battery voltage detection circuit 12 operates the latch release circuit 18 together with the switching control circuit 14, and the power supply switching circuit 14 disconnects the battery from the load.

As described above, according to this embodiment, by applying a latch to the power supply switching circuit, sudden changes in load can be caused by:; , I++
A stable power supply can be provided even with voltage fluctuations.

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

FIG. 2 shows a block diagram of a power supply device in another embodiment of the present invention. In FIG. 2, 21 is a power failure detection signal, 22 is a battery voltage detection circuit that detects battery voltage, 23 is a power supply switching circuit, 24 is a switching control circuit that controls the power supply switching circuit 23, 25 is a battery, 2G is a latch circuit, and 27 is a latch release circuit for releasing the latch circuit 20.

The battery 25 is connected to a battery voltage detection circuit 22, and the output of the battery voltage detection circuit 22 is connected to a power supply switching circuit 23 and a latch release circuit 27. The latch f' circuit 2G is connected to the outputs of the switching control circuit 24 and the latch release circuit 27, and is connected to the output of the power supply switching circuit 23.

The operation of the power supply device configured as described above will be described below. In this embodiment, commercial power is directly supplied to the load side, and a power failure detection signal is output from the load side. When the commercial power supply stops, a power failure detection signal is output. Next, the switching control circuit 24 receives a determination signal from the battery voltage detection circuit 22 as to whether or not the battery voltage can be supplied to the 11 loads, and if the battery voltage can be supplied, the power supply switching circuit 24
make it work. Next, the switching control circuit 24 operates the latch circuit 23 together with the power supply switching circuit, and latches the operation of the power supply switching circuit 23. Therefore, even if the battery voltage fluctuates due to sudden changes in load, it is possible to provide stable power supply. Furthermore, when the commercial power supply is restored, the output of the power failure detection signal 21 will stop, so the switching control circuit operates the latch release circuit 27, and the power switching circuit 23 disconnects the battery 25 from the load. When the battery voltage drops and cannot be supplied to the load, the battery voltage detection circuit 22 operates the latch release circuit 27 together with the switching control circuit 24 to disconnect the battery 25 from the load.

As described above, according to this embodiment, a voltage conversion circuit is not required, so that a cheaper power supply device can be obtained.

In this embodiment, the switching control circuit and the latch circuit are separate circuits, but they can be integrated into one circuit by incorporating a latch function into one switching circuit. It is also possible to combine the latch release circuit and the latch circuit into one. In this way, in the present invention, the circuit has various configurations,
It can perform the same function.

Effects of the Invention As described above, the power supply device of the present invention includes a first voltage detection means for detecting power outage and restoration of the main power source, and an auxiliary power source that supplies power to the load during a power outage of the main power source, If the main power supply switches to the auxiliary power supply during a power outage, and the auxiliary power supply voltage drops while the auxiliary power supply is connected to the load, the auxiliary power supply is disconnected from the load, and even if the auxiliary power supply voltage increases in this state, the disconnection is maintained. , consists of a control means that connects the main power supply and the load when the main power supply is restored, so even if the voltage of the auxiliary power supply such as a battery fluctuates due to sudden changes in the load, a stable power supply can be maintained. I can do it.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a first embodiment of the power supply device of the present invention, Fig. 2 is a block diagram of the second embodiment of the same, Fig. 3 is a block diagram of a conventional power supply device, and Fig. 4 is the same. 3 is a graph showing changes in battery voltage over time. 11----1----Power outage detection circuit 12.22--
m-Battery voltage detection circuit 13.2J---One power supply switching circuit 14.24---All switching control circuit 15.25---One battery 16---Voltage conversion circuit 17. 26--
--Latch circuit

Claims (1)

[Claims] a first voltage detection means for detecting power outage/recovery of the main power supply;
an auxiliary power supply for supplying power to the load during a power outage of the main power supply; a second voltage detection means for detecting the voltage of the auxiliary power supply; and a power supply for selectively connecting the main power supply and the auxiliary power supply to the load. switching means; when the main power supply is connected to a load by the power supply switching means, when the first voltage detection means detects a power outage of the main power supply, the power supply switching means connects the auxiliary power supply to the load; When the second voltage detection means, to which the auxiliary power supply is connected to the load, detects that the voltage of the auxiliary power supply has become below a predetermined value, the power supply switching means disconnects the load from the auxiliary power supply, and When the load is disconnected from the auxiliary power source, the auxiliary power source and the load are maintained disconnected regardless of the voltage of the auxiliary power source, and when the first voltage detection means detects that the main power source has been restored, the main power source is A power supply device characterized by comprising a control means for controlling connection between a power source and a load.