JPH06284600A - Emergency power supply and emergecy lighting apparatus - Google Patents

Abstract

PURPOSE:To prevent breakdown of a semiconductor element, etc., by preventing a sharp current to enter a smoothing capacitor through a control electrode of a semiconductor device from a battery in a power supply limiting apparatus. CONSTITUTION:When a battery 2 is connected to a working power supply 1 before a charger 3 is connected thereto, since charge of a smoothing capacitor 7 of the charger 3 is zero, current tends to rush to the smoothing capacitor 7 through the emitter and base of the transistor 10 and that of the transistor 11. However, in this case, a resistor 13 of the current limiting apparatus reduces the current. Thereby, no excessive current flows into the transistors 10, 11 and therefore breakdown of the transistors 10, 11 can be prevented.

Description

Detailed Description of the Invention

[Object of the Invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emergency power supply device having a battery for an emergency such as a power failure of a regular power supply, and a disaster prevention lighting device using such an emergency power supply device.

[0003]

2. Description of the Related Art Hitherto, various types of emergency power supply devices have been proposed for use in disaster prevention lighting such as evacuation guide lights and emergency lighting. For example, the one shown in FIG. 3 has been proposed. In FIG. 3, 1 is a commercial AC power source as a regular power source, and 2 is a battery charged by the regular power source 1. Reference numeral 3 is a charging circuit for charging the battery 2, and is composed of, for example, a step-down transformer 4, a rectifying circuit 5, a dropper type constant voltage circuit 6 and a smoothing capacitor 7. Reference numeral 8 is a load of the battery 2, for example, a light bulb or the like. A switching circuit 9 is provided to control the power supply from the battery 2 to the load 8. As the switching circuit 9, a contactless type using a semiconductor switch has been widely adopted in recent years from the viewpoint of downsizing and reliability. 3 mainly comprises a pair of Darlington-connected transistors 10 and 11, and the collector / emitter of the transistor 10 is interposed between the battery 2 and the load 8. Also, a transistor 1 Darlington connected to the transistor 10.
1 to the positive electrode of the charging circuit 3 and a resistor 12
It is connected to the negative electrode of the charging circuit 3 via. Therefore, when the utility power supply 1 is normal, that is, when the predetermined output is generated in the charging circuit 3, the transistor 11 is reverse-biased and turned off, and the transistor 10 is also turned off. Therefore, the battery 2 can supply power to the load 8. Absent. On the other hand, when the utility power supply 1 is abnormal, that is, when the charging circuit 3 does not generate a predetermined output, the battery 2 causes the transistors 10, 11,
The transistors 10 and 11 are biased through the resistor 12, and the transistors 10 and 11 are turned on to supply power to the load 8. Note that 13 is a current limiting resistor, 1
Reference numeral 4 is a diode for preventing backflow.

[0004]

The conventional emergency power supply device operates as described above, but in this one, the emergency power supply device is incorporated into a certain device, for example, a disaster prevention illumination device, and this device (disaster prevention illumination device) is installed in a facility. It was found that the following problems would occur when installed in That is, when the battery 2 is connected to the circuit before the installation of the disaster prevention lighting device or the like is completed and the electric wiring work is not completed, the steep current from the battery 2 causes the transistor 10, The current may flow into the smoothing capacitor 7 via the emitter base 11 and the current may destroy the transistors 10, 11 and the like. This is because a battery that is fully charged at the initial stage is generally used, while the smoothing capacitor 7 before the normal power source 1 is connected has no electric charge.

The present invention has been made to solve such a conventional problem, and is an emergency power supply device capable of reliably preventing the semiconductor elements of the switching circuit from being destroyed, or such an emergency power supply device. It is intended to provide a disaster prevention lighting device using the.

[Constitution of Invention]

[0007]

According to a first aspect of the present invention, there is provided a charging circuit for rectifying and smoothing a common power supply voltage, and a charging circuit which is normally charged from the common power supply via the charging circuit and which has an emergency function. A battery for supplying electric power to a load is provided at some times, and a pair of main poles is inserted between the battery and the load, and a control pole is supplied with a signal corresponding to the presence or absence of the output of the charging circuit to conduct electricity. Controlling a power supply from the battery to the load by a switching circuit having a semiconductor element controlled by a current limiting circuit, and limiting a current between a control pole of the semiconductor element of the switching circuit and a positive side output terminal of the charging circuit. The device is characterized by being inserted.

In the present invention, the current limiting device is a resistor, a diode or another impedance element,
It can be configured using a switching element or the like.

According to a second aspect of the present invention, there is provided a first lighting load which is normally energized by a regular power source, the emergency power supply device according to the first aspect, and the emergency power source when the regular power source is in an emergency. A second lighting load energized by the battery of the power supply;
It is characterized by configuring a disaster prevention lighting device.

The invention described in claim 3 is characterized in that, in the invention described in claim 2, the first lighting load and the second lighting load are made common.

[0011]

According to the first aspect of the present invention, the current limiting device effectively prevents a steep current from flowing from the battery to the smoothing capacitor through the control pole of the semiconductor element, and prevents the semiconductor element or the like from being destroyed. To prevent.

The invention described in claims 2 and 3 also provides a disaster prevention illumination device in which the emergency power supply device is prevented from being destroyed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG. The same or corresponding parts as those in FIG. 3 are designated by the same reference numerals and the description thereof will be omitted. In this embodiment, a resistor as a current limiting device 20 is inserted between the base of the transistor 11 of the switching circuit 9 and the positive output terminal of the charging circuit 3.

Further, in this embodiment, a transistor 21 whose conduction is controlled by the voltage across the resistor 13 between the charging circuit 3 and the battery 2 is provided, and the resistor 22 is connected in series with the transistor 21 and the load 8. And light emitting element 2
3 is provided, and the light emitting element 23 is used for charging display.

In this embodiment, the capacitor 25 is provided in parallel with the emitter base of the transistor 61 of the constant voltage circuit.

The operation of this embodiment will be described. If the battery 2 is connected before the charging device 3 is connected to the utility power source 1, the charge of the smoothing capacitor 7 of the charging circuit 3 is zero, so that the emitter base of the transistor 10 and the emitter base of the transistor 11 are connected. A steep current tries to flow into the smoothing capacitor 7 via the capacitor. However, in this embodiment, the resistance as the current limiting device 20 reduces the steep current. Therefore, an excessive current does not flow through the transistors 10 and 11, and the transistors 10 and 11 are not destroyed.

The normal power supply 1 and the emergency power supply 1 operate in the same manner as in FIG. In addition, in the present embodiment, when the battery 2 is charged when the utility power supply 1 is normal, a voltage corresponding to the charging current is generated across the resistor 13,
The transistor 21 turns on. Therefore, a current flows through the light emitting element 23 through the transistor 21 and the load 8 and the like, and the light emitting element 23 emits light to indicate that it is being charged. Since the current flowing through the light emitting element 23 is small (this setting is easy), the load 8 does not substantially emit light by this current. Such a light emitting element 23 can be provided at a position visible from the outside to serve as a charging monitor.

The present embodiment also prevents the electric charge of the smoothing capacitor 7 from adversely affecting the transistor 61 of the constant voltage circuit when the output voltage of the constant voltage circuit 6 drops due to a power failure of the regular power supply 1. is doing. That is, the capacitor 25 bypasses that the output voltage of the constant voltage circuit 6 decreases and the electric charge of the smoothing capacitor 7 is about to be applied to the emitter base of the transistor of the constant voltage circuit. Therefore, the transistor 61 is not destroyed.

When the present embodiment is applied as a disaster prevention lighting device such as a guide light which is required to be normally illuminated, the load 8 (bulb) is the second illumination device for emergency. Therefore, the first lighting device 26 that is always energized by the regular power supply 1 is provided. As the first lighting device 26,
Although detailed description is omitted, known ones such as a fluorescent lamp and a ballast, and a light bulb can be appropriately used. Then, the lighting control means 2 of the second lighting device 26
As for 7, a known means such as a power failure detection relay can be appropriately used.

A second embodiment will be described with reference to FIG. In this embodiment, a diode is used as the current limiting device 30. Further, in the present embodiment, the lighting device 31 serves as both the first lighting device and the second lighting device. As such an illuminating device 31, for example, a fluorescent lamp 32 is used as a light source, and the ballast 3 for the regular power supply 1 is used.
3, an inverter 34 for converting the DC voltage from the battery 2 into a high frequency voltage, and the like. Such an illuminating device itself, or switching means for switching the ballast 33 and the inverter 34, etc., are well known, and therefore detailed description thereof will be omitted. Since the operation of the present embodiment can be easily understood from the drawings and the above description, the description thereof will be omitted.

The present invention is not limited to the above embodiment. For example, the semiconductor element forming the switching circuit may be any other element such as a thyristor other than a transistor, as long as it has a similar function. Further, the specific circuit configuration can be modified as appropriate, and such modification is easy for those skilled in the art.

[0022]

As described above, according to the first aspect of the present invention, the current limiting device prevents a steep current from flowing from the battery to the smoothing capacitor via the control pole of the semiconductor element. Even if the battery is connected before connecting to the regular power source, it is possible to prevent the semiconductor element or the like from being destroyed.

The inventions according to claims 2 and 3 can also provide a disaster prevention lighting device capable of preventing the destruction of the emergency power supply device.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a second embodiment of the present invention.

FIG. 3 is a circuit diagram showing a conventional device 1 ... Regular power supply, 2 ... Battery, 3, 3 '... Charging circuit, 7 ... Smoothing capacitor, 8 ... Load, 9 ... Switching circuit, 20, 30 ... Current limiting device.

Claims (3)

[Claims] 1. A regular power supply; a charging circuit for rectifying and smoothing the regular power supply voltage; always charged from the regular power supply via the charging circuit and supplying power to a load in an emergency of the regular power supply. A battery; and a semiconductor element in which a pair of main poles is inserted between the battery and the load, and a control pole is supplied with a signal according to the presence or absence of an output of the charging circuit to control conduction. A switching circuit for controlling power supply from the battery to the load; and a current limiting device interposed between the control pole of the semiconductor element of the switching circuit and the positive output terminal of the charging circuit. Emergency power supply characterized by. 2. A first lighting load which is normally energized by a normal power supply; an emergency power supply device according to claim 1; and a battery of the emergency power supply device when the normal power supply is emergency And a second lighting load that is activated. 3. The disaster prevention lighting device according to claim 2, wherein the first lighting load and the second lighting load are common.