JP2607627Y2 - lighting equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device for lighting a discharge lamp at a high frequency.

[0002]

2. Description of the Related Art Conventionally, a high-frequency converter for converting a DC voltage of a DC power supply into a high-frequency voltage and supplying power to a discharge lamp has been often used. This type of high-frequency converter includes an insulation type that completely separates an input unit that receives a DC voltage and an output unit that outputs a high-frequency voltage magnetically using an insulating transformer or the like, and insulates the input unit and the output unit. Some are non-insulated types. In recent years, there has been an increasing demand for miniaturization, weight reduction, and flexibility in shape due to computerization, and no insulating transformer is used. For example, Japanese Patent Application No. 60-113720 (Japanese Unexamined Patent Application Publication No.
A high-frequency conversion device such as that described in Japanese Patent Application Laid-Open No. 1-271794) is often used.

FIG. 5 shows an example of such a high-frequency converter, which is connected to a DC power source E and generates a high-frequency voltage in a non-insulated manner. Output filament terminal F
The discharge lamp FL1 having the first and the second lamps F2 is connected and configured.

Here, a DC power supply E is connected to a diode D1,
D2, a series circuit of smoothing capacitors C1 and C2 connected to both ends of the series circuit, and an AC power supply AC connected to the midpoint of each series circuit. DC voltage is output to both ends of the series circuit. The high-frequency converter INV includes switching elements Q1 and Q2 that are connected in series to both ends of a series circuit of the smoothing capacitors C1 and C2 and that are alternately turned on and off.
It comprises diodes D3 and D4 reversely connected to the respective switching elements Q1 and Q2, capacitors C3, C4 and C5 forming an oscillating circuit, an inductor L1, and a driving transformer T1 for driving the switching elements Q1 and Q2. The capacitance value of the capacitor is set so that capacitor C3> capacitors C4 and C5. The discharge lamp FL1 has filaments F1 and F2 such as a fluorescent lamp, and is connected to both ends of a switching element Q1 of the high-frequency converter INV via a DC cut capacitor C3, an inductor L1, and a drive transformer T1. . And the discharge lamp F
A resonance capacitor C5 is connected between the power supply side filament terminals (F1-F2) of L1, and a preheating capacitor C4 is connected between the non-power supply side filament terminals (F1-F2) of the discharge lamp FL1.

Next, the operation state of the high-frequency converter INV will be briefly described. First, when a DC voltage is received from a DC power supply E, a starting circuit (not shown) switches the switching element Q2.
Is supplied with a forward bias signal, and shifts to the ON state. When the switching element Q2 is turned on, the DC power supply E switches the DC cut capacitor C3 → the capacitor C5 → the inductor L1 → the driving transformer T1 → the switching element Q2.
→ A first closed circuit leading to the DC power supply E is formed, a voltage is generated in the secondary winding of the drive transformer T1 to bias the switching element Q2 in the forward direction, and the switching element Q2 is continuously turned on. Thereafter, when the polarity of the voltage generated in the driving transformer T1 is inverted, the switching element Q
1 shifts to the ON state, and the DC-cut capacitor C3 switches the ON-state switching element Q1 to the drive transformer T1.
A second closed circuit from the inductor L1 to the resonance capacitor C5 to the DC cut capacitor C3 is formed, and a voltage that continuously biases the switching element Q1 in the secondary winding of the drive transformer T1 is continuously generated.

Thus, the switching elements Q1, Q2
Are turned on and off alternately, current flows alternately in the first and second closed circuits, and a high voltage is generated across the resonance capacitor C5 to start the discharge lamp FL. Also, the discharge lamp F
A current flows through the preheating capacitor C4 connected between the non-power-supply-side filament terminals of the discharge lamp FL, so that the filaments F1 and F2 of the filaments F1 and F2 have the same characteristics.
F2 is preheated as appropriate.

However, the high-frequency converter INV
Has a problem that the leakage current to the ground increases due to the non-insulation type configuration. This will be described below.

FIG. 6 is a structural view for explaining the lighting fixture 6, which comprises a first socket 1 and a second socket 2 located at both ends, and the first and second sockets. A discharge lamp 3 such as a straight tube type fluorescent lamp (FL1 shown in FIG. 5) having a filament terminal mounted on each of the first and second lamps 1 and 2 and conductive instrument side plates 4 and 5 is provided. Such lighting fixtures 6 are often of a ceiling embedded type, and a third-class grounding work is generally performed on the fixture body.

Therefore, the lighting fixture 6 shown in FIG.
When the high frequency conversion device INV shown in
When the discharge lamp 3 (FL1) is removed, the filament terminals (F1, F2 in FIG. 5) may come into contact with the appliance side plates 4, 5. Assuming that the filament terminal F1 comes into contact, the filament terminal F1 reaches the appliance side plates 4, 5 → the appliance main body 6 → the third type grounding work → the ground → the AC power supply (AC shown in FIG. 5) → the filament terminal F1. A closed circuit is formed, and a leakage current flows. If this current is large, the earth leakage breaker installed on the AC power supply AC side will work and cut off the power supply of the AC power supply AC. An extremely inconvenient situation occurs in that even the lighting equipment becomes a point.

[0010]

The problem to be solved by the present invention is that an AC power supply is cut off due to a leakage accident that may occur when the discharge lamp is replaced, and many lighting fixtures become inconsistent. It is an object of the present invention to provide a lighting fixture that does not require a safer AC power supply by suppressing the leakage current to an extremely small value even in the event of an accident. It is in.

[0011]

SUMMARY OF THE INVENTION The present invention provides a DC power supply,
Straight with a high-frequency converter of the half bridge type that occurs in the non-insulated the connected high-frequency voltage to the direct current power source, a filament terminal connected to the output of the high frequency converter
And a tubular discharge lamp, the high-frequency converter, the direct
In a lighting fixture including an impedance element connected in parallel between power supply terminals of a tube-type discharge lamp, and a vibration circuit including the impedance element, replacement of the straight tube-type discharge lamp Sometimes the filament terminal with the higher ground voltage can release the electrical connection from the high-frequency converter first .
Thus, the moving distance of the opposed socket is made different .

[0012]

According to the present invention, at the time of replacement of a straight tube type discharge lamp, at least the filament terminal having a higher ground voltage is so connected that the electrical connection from the high frequency converter can be released first.
It is characterized by the fact that the moving distance of the bracket is made different, so even if the filament terminal of the discharge lamp comes into contact with a conductive outer shell such as lighting equipment when replacing the discharge lamp, the leakage current flowing to the ground can be reduced. By suppressing the power and improving the safety, there is an effect that the AC power supply is not interrupted by the earth leakage breaker or the like.

[0013]

1 is a circuit diagram showing a first embodiment of the present invention. The DC power supply E includes a rectifier DB for rectifying the AC voltage of the AC power supply AC, a switching element Q3 connected to both ends of the rectifier DB via a chopper inductor L10, and a diode D10 connected to both ends of the switching element Q3. And a smoothing capacitor C10 connected thereto, and outputs a DC voltage to both ends of the smoothing capacitor C10.

The high-frequency converter INV includes switching elements Q1 and Q2 connected in series at both ends of the smoothing capacitor C10 and alternately turned on and off, and diodes D3 and D4 reversely connected to the respective switching elements Q1 and Q2.
And capacitors C3, C4, forming a first oscillation circuit
It is composed of an inductor L1, capacitors C31 and C41 forming a second oscillation circuit connected in parallel with the first oscillation circuit, an inductor L11, and a drive transformer T1 for driving the switching elements Q1 and Q2. The values are for DC cut capacitors C3 , C31 preheating and
And the resonance capacitors C4 and C41.

The discharge lamp FL1 is connected to both ends of a switching element Q2 of the high-frequency converter INV via a DC cut capacitor C3, an inductor L1, and a drive transformer T1. A preheating capacitor C4 is provided between the non-power supply side filament terminals (F1-F2) of the discharge lamp FL1.
Is connected. Similarly, the discharge lamp FL11 is also configured. The discharge lamps FL1 and FL11 are both straight tube lamps.
It is a light.

The configuration different from FIG. 5 showing the prior art example is that a DC power supply E is configured as a chopper, that discharge lamps FL1 and FL2 are connected to both ends of a switching element Q2, and that a multi-lamp configuration is used. And the starting circuit is connected to the resistor R1
0, a capacitor C11, a diode D11, and a diac Q4. In addition, the same configuration
The same reference numerals are given and duplicate descriptions are omitted.

Next, an operation state will be described. First, when an AC voltage is received from the AC power supply AC, the switching element Q3 of the chopper circuit starts an on / off operation, and a boosted DC voltage is generated across the smoothing capacitor C10. When this DC voltage is received, the capacitor C11 of the starting circuit becomes the resistor R
10 and when the voltage reaches a predetermined voltage, the diac Q
4 is turned on, a forward bias current is supplied from the capacitor C11 to the switching element Q2, and the switching element Q2 is turned on. When charging the capacitor C11,
DC power supply E → resistance R11 (or resistance R10 → diode
Mode D11) → drive transformer T1 → inductor L1 (L
11) → Preheating and resonance capacitor C4 (C41) →
DC cut capacitor C3 (C31) → DC power supply E
A closed circuit is formed in the path, and the DC cut capacitor C3
(C31) is charged. And the switching element Q
2 is turned on, the DC cut capacitor C3
(C31) → Preheating and resonance capacitor C4 (C4
1) → Inductor L1 (L11) → Drive transformer T1 →
Switching element Q2 → DC cut capacitor C3
(C31) is formed, and the drive transformer T1
The switching element Q2 in the forward direction to the secondary winding of
Voltage, and the switching element Q2 is continuously turned off.
On state. After this, it occurs in the drive transformer T1.
When the polarity of the voltage is reversed, the switching element Q1 is turned on.
State (switching element Q2 is turned off).
From the DC power supply E to the switching element Q1
Lance T1 → Inductor L1 (L11) → For preheating and
Vibration capacitor C4 (C41) → DC cut capacitor
A closed circuit from C3 (C31) to DC power supply E is formed.
The switching element Q is connected to the secondary winding of the drive transformer T1.
A voltage for continuously biasing 1 in the forward direction is continuously generated. Since then
An oscillating voltage is generated in the first and second oscillating circuits, and the switching elements Q1 and Q2 are alternately forward-biased to discharge the lamp FL.
1 and FL11 are continuously supplied with high-frequency power.

FIG. 2A shows a change in the potential at the point X shown in FIG. 1, FIG. 2B shows a change in the potential at the point Y shown in FIG. 1, and FIG. Figure 1
Shows the change in the potential at the point Y shown in FIG. Where X point
The potential at the point Y is the negative electrode of the smoothing capacitor C10 shown in FIG.
It is based on the side potential. Thus, the potential at point X is
At the time of lighting, the DC voltage becomes a flat DC voltage as shown in FIG. 2A, and the potential at the point Y generates a DC voltage shown in FIG. 2A with respect to the negative electrode side (circuit ground point) of the smoothing capacitor C10 as shown in FIG. The waveform has a waveform in which the discharge lamp potential is superimposed on this DC voltage. When the discharge lamp FL1 is removed, a potential as shown in FIG. 2C is generated at the point Y. This
This means that even if one light is off, the other light is on, and oscillation
This is because it is continuing.

Now, a case where the discharge lamp FL1 is detached will be described with reference to an apparatus configuration diagram shown in FIG. First, a state will be described in which the filament terminals F1 and F2 located at both ends of the discharge lamp FL1 deviate from the state where they are mounted on the movable sockets 1 and 2, respectively.

FIG. 3A shows a case where the socket 1 side comes off first, and one of the filament terminals F1 which has contacted the socket 1 is connected to the instrument side plate (4, 5 shown in FIG. 6).
It is assumed that the contact is made. Generally, a discharge lamp FL1 such as a fluorescent lamp is considered as a resistor having a negative characteristic (having a certain conductance in terms of conductance) at the time of lighting, and even if the discharge lamp FL1 comes off, its conductance is instantaneously increased. It does not mean that it will be zero.
Therefore, until the conductance of the discharge lamp FL1 becomes zero.
Is a high frequency converter (INV shown in FIG. 1) → discharge lamp FL
1 → filament terminal F1 → instrument side plate (4 shown in FIG. 6,
5) Very small and problematic levels in the closed circuit leading to → ground → AC power supply (AC shown in FIG. 1) → high frequency converter
Not Le, so that the leakage current flows. This is
Even if the electric lamp FL1 comes off, the discharge lamp FL11 (capacitor C4
Since 1) is connected to the high-frequency converter, the discharge lamp FL
Until the conductance of 1 becomes zero, X
The potential at the point is equal to the negative potential of the smoothing capacitor C10.
Approximately flat with the voltage across the capacitor C3 added
This potential does not substantially fluctuate as a high frequency.
Flat potential minimizes leakage current
You can do it.

Next, considering the case where the socket 2 side shown in FIG. 3B comes off first and comes into contact with the appliance side plate (4, 5 shown in FIG. 6), the closed circuit as described above is also large in this case.
A leakage current of an appropriate value will flow. This is the discharge lamp F
Discharge lamp FL11 (condenser C41) even if L1 comes off
Because it is connected to the high frequency converter, the Y point of the high voltage side terminal
(That is, the inductor L1 and the inductor L11)
Oscillates as shown in FIG. 2C.
High frequency high voltage is generated, and this high frequency high voltage
Therefore, the value of the leakage current increases. Therefore, a leakage breaker for safety provided in the AC power supply AC operates to cut off the power supply. This is a necessary protection operation for safety, but when a large number of lighting fixtures are installed, there is a problem since other lighting fixtures are turned off.

Therefore, when the discharge lamps FL1, FL11, etc. come off from the sockets 1, 2, the socket 1 on the Y point side is fixed to X so that it always comes off from the Y point side, which is the high pressure side.
The socket 2 on the point side is configured to be movable. With this configuration, even when the discharge lamps FL1 and FL11 are removed, even if the discharge lamps FL1 and FL11 come into contact with the appliance side plate, the Y-point side where the leakage current is extremely small always contacts, and a safe lighting with a small leakage current is ensured. We can provide equipment. In addition, an undesired operation of the earth leakage breaker can be avoided.

FIG. 4 is a circuit diagram showing a second embodiment of the present invention. In the conventional example shown in FIG. 5, even when the straight tube type discharge lamp FL1 is removed, the inductor L1 and the resonance capacitor C are removed.
5, the high-frequency converter INV will continue to oscillate. In this case, the point X when the discharge lamp FL1 comes off is shown in FIG. 2 with respect to the circuit ground point (negative electrode side of the capacitor C2) of the high-frequency converter INV.
Since the waveform is the same as that shown in FIG.
When the filament terminal F1 comes off and comes into contact with the instrument side plate, a leakage current flows due to the closed circuit as described above.

Therefore, a filament terminal connected to one socket 1 of the movable socket is connected to the Y point side shown in FIG. The configuration in which the discharge lamp 3 (FL1 shown in FIG. 5) can be removed only from the socket 2 prevents an excessive leakage current from occurring. In addition,
In the first embodiment, the power supply side end of the discharge lamp FL1
The impedance element connected in parallel between the
Whether the ductor L11, discharge lamp FL11, condenser C31, etc.
A series circuit consisting of
May be adopted.

[0025]

[Effects of the Invention] The present invention can suppress the leakage current flowing to the ground even if the filament terminal of the discharge lamp comes into contact with a conductive outer shell such as a lighting fixture at the time of replacement of the straight tube type discharge lamp, thereby ensuring safety. Has a remarkable effect that the AC power supply is not interrupted by the earth leakage breaker or the like.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram showing waveforms of respective units for explaining the first embodiment of the present invention.

FIG. 3 is a schematic view of the first embodiment of the present invention;

FIG. 4 is a schematic view of a device according to a second embodiment of the present invention.

FIG. 5 is a circuit configuration diagram showing a conventional example of the present invention.

FIG. 6 is a diagram showing the configuration of a device according to a conventional example of the present invention.

[Explanation of symbols]

 E DC power supply INV High frequency converter FL1,3 Discharge lamp 6 Lighting equipment

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-155003 (JP, A) JP-A-3-98294 (JP, A) JP-A-1-251588 (JP, A) 103299 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H05B 41/24-41/298

Claims (1)

(57) [Scope of request for utility model registration] 1. A straight-tube type having a DC power supply, a half-bridge type high-frequency converter connected to the DC power supply and generating a high-frequency voltage without insulation, and a filament terminal connected to an output of the high-frequency converter. A lighting device comprising: an impedance element connected in parallel between power-supply-side terminals of the straight tube type discharge lamp; and a vibration circuit including the impedance element. In the replacement of the straight tube type discharge lamp, the moving distance of the opposing socket is different so that the filament terminal having a higher ground voltage can be disconnected earlier from the high-frequency converter when the filament terminal has a higher ground voltage.
Lighting equipment characterized by having been made .