JPS6121398B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lighting device, and more particularly to a lighting device that prevents transmission of high-frequency noise to the power source side of a lighting fixture caused by high-frequency lighting.

[Conventional technology]

In general, lighting equipment equipped with a discharge lamp such as a fluorescent lamp contains a high frequency component when turning on and off every half cycle of the power supply.

[Problem that the invention seeks to solve]

The high frequency components are transmitted to the power supply side via the power line and become high frequency noise.Recently, electronic lighting circuits using high frequency inverters that oscillate at several tens of kilohertz have been proposed as lighting circuits. The problem of high frequency noise was noticeable in such high frequency lighting equipment.

Therefore, it is conceivable to obtain a noise shielding effect by covering the insulated power supply line that connects the high frequency generator to the power supply with a tube at the part where the power supply line is introduced into the lighting fixture body. It is conceivable to use a metal tube as this tube, but although metal tubes can be expected to have a noise shielding effect to some extent, depending on the distance and thickness, there is no noise shielding effect when the lighting equipment body is installed. Furthermore, the use of such a large diameter metal tube is expensive, heavy, requires a supporting structure, is cumbersome to mount, and has design problems.

The present invention has been made in view of the above problems, and it increases the noise shielding effect with a simple structure by covering the insulated power supply line that connects the high frequency generator to the power supply with an insulating tube that introduces it into the lighting equipment body. The present invention provides a lighting device that prevents transmission of high frequency noise to a power source.

[Means for solving problems]

The present invention provides a lighting fixture body formed of a conductive material, a high frequency generator built into the fixture body, a discharge lamp lit by the output of the high frequency generator, and a power source using the high frequency generator. The lighting device is characterized in that it comprises a connecting power wire coated with insulation, and a portion of the power wire where the lighting fixture body is introduced is covered with an insulation tube.

[Effect]

The present invention provides that even if high-frequency noise is induced in the power line due to high-frequency lighting of a discharge lamp, a dielectric layer made of air between the inner surface of the insulating tube and the outer periphery of the power line is provided between the power line and the lighting equipment body. There is a dielectric material made of air between the outer periphery of the insulating tube and the inner surface of the instrument body, and a dielectric material of the insulating tube itself outside, and high-frequency noise is generated by stray capacitance caused by these dielectric materials. is bypassed and the noise voltage is reduced.

〔Example〕

The configuration of an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, 1 is a commercial AC power source, 2 is a rectifier circuit, and is connected to the AC power source 1 via a power line 3 and a well-known noise prevention filter F. The positive side electric line 4 on the DC side of the rectifier circuit 2 is connected via a constant current reactor 5, and the negative side electric line 6 is directly connected to a constant current type high frequency generator, for example, an inverter 7. This inverter 7 has a configuration in which a pair of transistors 8 and 9 are connected in a push-pull manner.
Connect to the winding start end and winding end of numbers 1 and 12.
The emitters of these transistors 8 and 9 are commonly connected. Further, the bases of these transistors 8, 9 are connected to the electric path 4 via starting resistors 13, 13. Further, the primary winding 11 of the inverter transformer 10,
A resonant capacitor 14 is provided between both ends of 12, and an electric line 4 is connected to the midpoint. Furthermore, the inverter transformer 10 has a feedback winding 1 on the primary side.
5, the ends of which are connected to the bases of the transistors 8 and 9 to form a positive feedback circuit to maintain oscillation. Further, a secondary winding 16 and a filament power supply winding 17 are provided on the secondary side of the inverter transformer 10 to supply power to the discharge lamp group.

The discharge lamp group constitutes a multi-lamp lighting circuit of five lamps. That is, a three-lamp series circuit including the first, second, and third discharge lamps 48, 19, and 20;
Balancer transformer 2 connected to one end of a two-lamp series circuit including fourth and fifth discharge lamps 21 and 22
3, and the parallel connection point is the secondary winding 16 of the inverter transformer 10.
Connect to both ends of the

Further, the second, third and fifth discharge lamps 19,
20 and 22 have starting capacitors 24, 25, and 26 connected in parallel.

Further, 27 is a filament transformer, and the primary winding 47 of this filament transformer 27 is the filament wire winding 17 of the inverter transformer 10.
Connect with. Also, this filament transformer 27
The secondary side of the lamp has six first to sixth filament windings 28, 29, 30, 31, 32, 33, and this first filament winding 28 is connected to the first and fourth discharge lamps 18. . The wire 30 is connected to the other filament circuit end of the second discharge lamp 19 and one filament circuit end of the third discharge lamp 20, and the fourth filament winding 31 is connected to the other filament circuit end of the third discharge lamp 20. Then, the fifth filament winding 32 is connected to the other filament circuit end of the fourth discharge lamp 21 and one filament circuit end of the fifth discharge lamp 22, and the sixth
The filament winding 33 of the fifth discharge lamp 22 is connected to the other filament circuit end of the fifth discharge lamp 22. Each of the filament circuits described above consists of a circuit in which two filaments are connected in parallel and a circuit in which two filaments are directly connected. The wires are set up so that each filament is preheated to the same voltage.

The lighting device configured as described above is turned on by turning on a power switch (not shown), which converts the supplied AC power into DC power in the rectifier circuit 2.
After converting the inverter 7 into high-frequency power, the output is sent to each discharge lamp 18, 19, 2 via an inverter transformer 10 and a filament transformer 27.
0, 21, and 22 to preheat each filament and start and light it. The inverter 7
is a constant current high frequency generator having constant current characteristics using a re-cage transformer for the inverter transformer 10, and each discharge lamp 18, 19, 20, 21,
A constant current flows through 22, turning it on. Although the transmission of high-frequency noise to the power supply 1 side is reduced to some extent by the noise prevention filter F, high-frequency noise is still present in the power supply line 3 due to stray capacitance between the power supply line 3 and components on the high-frequency generator side. being communicated.

Next, a lighting fixture body incorporating a lighting device including the high frequency generator will be described with reference to FIG. 2.

35 and 36 are printed wiring boards, and one board 35 has components connected to the primary side of the inverter transformer 10, which is an insulation transformer of the lighting device, such as two rectifier circuit components, a constant current reactor 5, a transistor 8, Connect 9 etc. Further, the balancer transformer 23, filament transformer 27, etc. connected to the secondary side of the inverter transformer 10 are connected to the other board 36. Both boards 35 and 36 are housed and fixed in a housing-like lighting fixture main body 37 vertically. Five arms 38 extend radially from the outer surface of the instrument body 37, and each arm 3
At the tip of 8 is a discharge lamp 18, 1 such as a fluorescent lamp.
Light fixture 3 that accommodates 9, 20, 21, and 22, respectively.
9 is installed. Conductive wires 40 connected to the discharge lamps 18, 19, 20, 21, and 22 of this lamp 39 are connected to the secondary side of the inverter transformer 10 through the board 36.

Further, an inlet 42 for the power line 3 is opened on the upper surface of the instrument body 37, and a cylindrical mounting portion 43 is fixed to the upper surface of the instrument body 37 surrounding this inlet 42, and is attached to the instrument body 37. The portion 43 constitutes a lighting fixture body 45 made of a conductive material. The power wire 3 introduced from the mounting portion 43 into the instrument body 37 is composed of an insulated wire with an insulation coating, and as shown in FIG. 3A, the power wire 3 is inserted into an insulated tube 44 and the power wire Space 46 on the outside
Connect the power wire 3 from the mounting part 43 of the instrument body 45 to the instrument body 3 while covering it with the insulating tube 44.
By introducing the power line 3 into the rectifier circuit 7, the part of the power line 3 where the lighting device is introduced is covered with an insulating tube 44, and the power line 3 is connected to the rectifier circuit 2.

Next, the operation of this embodiment will be explained.

Even if high-frequency noise is induced in the power line 3 due to the high-frequency lighting of the discharge lamps 18, 19, 20, 21, and 22, the inner surface of the insulating tube 44 and the power line 3 are connected between the power line 3 and the lighting fixture body 45. A dielectric material made of air with a dielectric constant of ε ₀ between the outer periphery of the insulation tube 44 and a dielectric material made of air with a dielectric constant of ε ₀ between the outer periphery of the insulating tube 44 and the inner surface of the lighting fixture body 45; The insulating tube 44 has a dielectric constant of ε ₁ .
There is a dielectric consisting of itself.

Therefore, as will be described later, high frequency noise is bypassed by the stray capacitance generated by these dielectrics, and as a result, the high frequency noise voltage between the line and the ground is reduced.

Next, the case of the conventional device shown in FIG. 3B will be explained.

In the conventional device shown in FIG. 3B, there is only a dielectric material made of air with a relative permittivity of ε ₀ between the power supply line 3 and the inner surface of the device body 37, and the stray capacitance in this case is is smaller than Fig. 3A.

In other words, the relative permittivity of air is about 1, while the relative permittivity of the insulating tube 44 is about 2 to 3. Therefore, comparing FIG. 3A and B above, the impedance of stray capacitance is A is smaller.

The above will be described in more detail. That is,
Let C be the stray capacitance due to each dielectric in Figure 3A, and let C be the stray capacitance due to the dielectric in Figure 3B.
Assuming C ₀ , calculate each stray capacitance as follows: C=1/{d/ε ₀ -t(1/ε ₀ -1/ε ₁ )}...
(1) C ₀ = d/ε ₀ ...(2) Note that d = outer surface of power supply line 3 and lighting fixture body 45
distance t=thickness of the insulating tube 44, and in order to simplify the calculation, it is assumed that a dielectric material is interposed between the parallel plates.

becomes. From (1) and (2), Since ε ₀ =1 and ε ₁ =3, becomes.

From this, the dielectric capacitance in Figure 3A is larger than that in Figure 3B, and therefore the high frequency noise voltage appearing across this dielectric capacitance C is smaller than in Figure 3B, and the noise You can understand that high frequency noise generated in measuring instruments (or noise-disturbed devices) can be reduced.

Note that in FIGS. 3A and 3B, the high frequency noise source 47 indicated by e is a noise measuring device or a noise-disturbing device.

In addition, in FIGS. 3A and 3B, C ₁ is a stray capacitance with the ground, and the lighting fixture body 45 may be directly connected.

Next, the experimental results of the apparatus of the above embodiment are as follows.

AC power supply 100V 50Hz High frequency output 45KHz Discharge lamp 5 30W annular fluorescent lamps Power line Approx. 5mmφ Insulation tube Vinyl resin tube thickness 0.7 to 1mm, inner diameter approx. 10mmφ Mounting part Inner diameter approx. 13mmφ As a result of measurement under the above conditions, the distance between one line and the ground The noise voltage was 59dB. In contrast, it was 61 to 62 dB when no insulating tube was provided.
Therefore, high frequency noise was reduced by 2 to 3 dB.

〔Effect of the invention〕

According to the present invention, in a lighting device equipped with a discharge lamp that is lit at high frequency by a high-frequency generator, the high-frequency generator is provided and a power supply line connected to the interior of the lighting device formed of a conductive material is introduced into the lighting device. Since the part is covered with an insulating tube, this insulating tube provides a noise shielding effect and prevents the generation of high frequency noise.Moreover, the structure is simple and easy to assemble as the power line is simply covered with the insulating tube. For the insulating tube, it is possible to use an easily available existing material molded from vinyl resin, etc.
Compared to the case where a metal tube is used, it is effective even when the lighting fixture body is grounded, and it is light in weight, easy to install, and can be made at low cost.

[Brief explanation of the drawing]

FIG. 1 is a lighting circuit diagram of a lighting device showing one embodiment of the present invention, FIG. 2 is a sectional view of the same lighting device, and FIG.
FIG. 3A is an explanatory cross-sectional view schematically showing the dielectric of the power supply line, and FIG. 3B is an explanatory cross-sectional view schematically showing the dielectric of the conventional device. 1...Power source, 3...Power line, 7...Inverter of high frequency generator, 18, 19, 20, 21, 2
2... Discharge lamp, 44... Insulating tube, 45...
A lighting fixture body composed of a fixture body 37 and a mounting portion 43.

Claims (1)

[Claims] 1. A lighting fixture body formed of a conductive material, a high frequency generator built into the fixture body, and a discharge lamp lit by the output of the high frequency generator,
A lighting device comprising: an insulated power source wire that connects the high frequency generator to a power source; and an insulating tube covering the introduction portion of the power source wire into the lighting fixture body.