JPH09289091A - Lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting system of three wires which can prevent erroneous operation due to cross-over phenomenon. SOLUTION: This system has three wires which the two power lines of an ac power supply Vac are connected to one line for switching an illumination load on and off through the turning on and off of a wall switch SW1 or the like, and comprises the ac power supply Vac, the wall switch SW1 connected in series with the ac power supply Vac, a plurality of lighting devices A1, A2 connected in parallel with both end of the ac power supply Vac, and a three-wire detecting circuit 12 which detects the turning on and off of the wall switch SW 1. A level at which the three-wire detecting circuit 12 detects the turning on and off of the wall switch SW1, i.e., a three-wire detection level, is set to be higher when the wall switch SW 1 is turned off than when the wall switch SW1 is turned on.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device, and more particularly, to a lighting device for lighting a lighting load by an inverter circuit which is commonly used when an AC power source is energized and cut off.

[0002]

2. Description of the Related Art A circuit diagram of a conventional example according to the present invention is shown in FIG.

This circuit turns on and off the lighting load when the AC power supply Vac is energized (hereinafter referred to as "normal time") by turning on and off the two power supply lines of the AC power supply Vac and the wall switch SW1 for example. A lighting system that has a three-wire system for connecting with one line for switching the power supply, and uses one inverter circuit to share the lighting load at a high frequency during normal times and when the AC power supply Vac is cut off (hereinafter referred to as an emergency). An AC power supply Vac, a wall switch SW1 connected in series to the AC power supply Vac, a plurality of lighting devices A1 to An (n is a positive integer) connected in parallel to both ends of the AC power supply Vac, and a wall switch. Three-wire detection circuits 11 to 1 for detecting ON / OFF of SW1
n, and the discharge lamps La1 to Lan are used as the illumination loads of the respective lighting devices A1 to An. It should be noted that the three-line detection circuits 11 to 1n include, for example, one using a photo coupler. Further, FIG. 3 shows only the lighting devices A1 and A2.

The lighting device A1 has an AC power supply Vac when an abnormality occurs.
The fuse F1 that protects the three-wire detection circuit 11 and the lighting device A1 by cutting off the supply of the power supply voltage from the power source, the rectifier DB1 that rectifies the AC power supply voltage Vac via the fuse F1, and the output voltage of the rectifier DB1 A DC / DC converter 21 for converting and outputting a DC voltage;
An inverter circuit IN that converts the DC voltage output of the DC converter 21 into an AC high frequency voltage and supplies it to the discharge lamp La1.
V1, a secondary battery V1 for supplying a DC voltage to the inverter circuit INV1 in an emergency, a charging circuit 31 for charging the secondary battery V1 by the DC / DC converter 21, and a DC
/ DC converter 21 DC voltage output and secondary battery V1
The switching circuit 41 for switching the DC voltage output of the above and connecting to the inverter circuit INV1 and the control unit 61 for receiving the detection signal from the three-wire detection circuit 11 and controlling the oscillation operation of the inverter circuit INV1. Since the lighting devices A2 to An have the same configuration as the lighting device A1, the description thereof will be omitted.

Next, the operation will be briefly described. In normal times, when the wall switch SW1 is turned on, the 3-wire detection circuit 11 detects that the wall switch SW1 is turned on and the inverter circuit INV1 is detected.
To illuminate the discharge lamp La1 and charge the secondary battery V1 from the AC power supply Vac via the rectifier DB1, the DC / DC converter 21, and the charging circuit 31. When the wall switch SW1 is turned off, the 3-wire detection circuit 11
Turns off the wall switch SW1 to detect the inverter circuit I
The discharge lamp La1 is turned off by, for example, stopping the oscillation of NV1, and the rectifier DB1 and DC / D are connected from the AC power supply Vac.
Rechargeable battery V via C converter 21 and charging circuit 31
Charge 1. In an emergency, since the AC power supply Vac is cut off, the supply of the power supply voltage from the AC power supply Vac to the inverter circuit INV1 is cut off, and the secondary battery V1 serves as the power supply for the inverter circuit INV1 to oscillate the inverter circuit INV1. The discharge lamp La1 is lit at high frequency in an emergency manner.

[0006]

However, in the above-mentioned conventional example, since the fuse F1 is provided closer to the AC power supply Vac than the contacts of one end of the three-wire detection circuit 11 and one end of the AC power supply Vac, it is normal and Even if the fuse F1 is disconnected when the wall switch SW1 is turned off, as shown by the arrow in FIG.
AC power supply Vac → Fuse F2 → 3-wire detection circuit 12 → 3
Current flows through the 3-wire detection circuit 11 through the path of the wire detection circuit 11 → rectifier DB1 → AC power supply Vac.
1 detects that the wall switch SW1 is on, and the supply of the power supply voltage from the AC power supply Vac is cut off due to the disconnection of the fuse F1. Therefore, the inverter circuit INV1 is oscillated and the discharge lamp La1 is turned on, causing a problem of the wraparound phenomenon.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a lighting device having a three-wire system and capable of preventing malfunction due to a wraparound phenomenon.

[0008]

In order to solve the above problems, according to the invention of claim 1, a secondary battery which is always charged by the AC power supply when the AC power supply is energized, and a secondary battery when the AC power supply is energized. An inverter circuit that uses the AC power supply as the power supply voltage source and supplies a high frequency voltage to the lighting load by using the secondary battery as the power supply voltage supply source when the AC power supply is cut off, and the power supply from the AC power supply to the inverter circuit when the AC power supply is on. The switch that turns on and off the voltage supply and the output of the inverter circuit that detects the on / off state of the switch and blinks the lighting load is controlled, and the level at which the on / off state of the switch is detected is turned on when the switch is off. It is characterized by including a three-wire detection circuit higher than the time, and a fuse for disconnecting the connection between the AC power supply and the lighting load when an abnormality occurs.

According to the second aspect of the invention, the fuse is provided at a position closer to the AC power source than the input end of the three-wire detection circuit.

According to the invention described in claim 3, the lighting load is a discharge lamp.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a circuit diagram according to an embodiment of the present invention.

3 is different from the conventional example shown in FIG. 3 in that the lighting device A1 is provided with a current detector 51 for detecting the output current of the DC / DC converter 21 and transmitting the detection signal to the controller 61. As shown in FIG. 4, the level for detecting ON / OFF of the wall switch SW1 in the 3-wire detection circuit 11, that is, the 3-wire detection level is the 3-wire detection level L2 when the wall switch SW1 is OFF. It is set to be higher than the three-line detection level L1 at that time, and the same configurations as the other conventional examples are denoted by the same reference numerals and the description thereof will be omitted. The lighting devices A2 to A
Since n also has the same configuration as the lighting device A1, the description thereof will be omitted.

The operation will be briefly described below. When the wall switch SW1 is normally turned on, a signal having a higher level than the three-wire detection level L1 is input to the three-wire detection circuit 11, that is, the three-wire detection circuit 11 detects that the wall switch SW1 is on and the inverter circuit INV1 is turned on. Oscillate and discharge lamp L
a1 is turned on and the rectifier D is supplied from the AC power supply Vac.
The secondary battery V1 is charged via B1, the DC / DC converter 21, the current detection unit 51, and the charging circuit 31. It can be confirmed that a large current flows through the current detection unit 51 due to the lighting of the discharge lamp La1 and the charging of the secondary battery V1, and the lighting device A1 is operating normally. When the wall switch SW1 is turned off, a signal having a level lower than the three-wire detection level L2 is input to the three-wire detection circuit 11, the three-wire detection circuit 11 detects that the wall switch SW1 is off, and the inverter circuit INV1 is detected.
The discharge lamp La1 is turned off by stopping the oscillation of the secondary battery V1 and the secondary battery V1 is charged from the AC power supply Vac through the rectifier DB1, the DC / DC converter 21, the current detection unit 51, and the charging circuit 31. A current smaller than that when the wall switch SW1 is turned on flows to the current detection unit 51 because the discharge lamp La1 does not light and the secondary battery V1 is charged, and the lighting device A1
Can be confirmed to be operating normally.

Here, the reason why the 3-wire detection level L2 is made higher than the 3-wire detection level L1 is that the current flowing through the 3-wire detection circuit 11 due to the sneak phenomenon occurs when the fuse F1 is disconnected and the wall switch SW1 is off. This is to prevent the lighting device A1 from operating and lighting the discharge lamp La1 as detected by the detection circuit 11 when the wall switch SW1 is turned on.

With this configuration, the AC power supply Vac is switched from the inverter circuit IN by the fuse disconnection or the like.
When the power supply to V1 to INVn is cut off, it is possible to prevent malfunction of the lighting devices A1 to An when the wall switch SW1 is off, that is, the discharge lamp L due to the wraparound phenomenon.
It is possible to prevent erroneous lighting of a1 to Lan.

In the above embodiment, DC / D
The C converters 21 to 2n may be step-down converters or step-up converters, and inverter circuits INV1 to INV may be used.
Vn may have any configuration, and the discharge lamp is used as the illumination load, but other types of light sources may be used.

[0017]

According to the first and third aspects of the present invention, it has a three-wire system, can prevent malfunction due to a sneak-in phenomenon, and can supply a power supply voltage from an AC power supply when an abnormality occurs. It is possible to provide a lighting device capable of protecting the lighting load by blocking the light.

According to the second aspect of the present invention, the lighting device has a three-wire system and can prevent malfunction due to a sneak-in phenomenon, and cut off the supply of the power supply voltage from the AC power supply at the time of an abnormality to provide a lighting device. A lighting device that can be protected can be provided.

[Brief description of drawings]

FIG. 1 shows a circuit diagram of an embodiment according to the present invention.

FIG. 2 shows a three-line detection level in the above embodiment.

FIG. 3 shows a circuit diagram of a conventional example according to the present invention.

[Explanation of symbols]

 F Fuse INV Inverter circuit La Lighting load Vac AC power supply V1 Secondary battery SW switch 1n 3-wire detection circuit

Claims (3)

[Claims] 1. A secondary battery that is constantly charged by the AC power supply when the AC power supply is energized, and the AC power supply is a power supply voltage supply source when the AC power supply is energized, and the secondary battery is the power supply voltage when the AC power supply is shut off. An inverter circuit that supplies a high-frequency voltage to a lighting load as a supply source, a switch that turns on / off a power supply voltage from the AC power source to the inverter circuit when the AC power source is energized, and an on / off switch that detects the on / off state of the switch. In a lighting device including a three-wire detection circuit that controls the output of the inverter circuit in a direction of blinking a lighting load, and a fuse that disconnects the connection between the AC power supply and the lighting load when an abnormality occurs, the three-wire detection circuit includes: The level at which the switch is turned on and off is higher when the switch is off than when it is on. Lighting device according to claim. 2. The lighting device according to claim 2, wherein the fuse is provided closer to the AC power source than an input end of the three-wire detection circuit. 3. The lighting device according to claim 1, wherein the lighting load is a discharge lamp.