JP4585663B2 - Filter circuit, filter device and discharge lamp lighting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a filter circuit, a filter device, and a discharge lamp lighting device that further suppress electromagnetic interference.
[0002]
[Prior art]
Conventionally, when this kind of discharge lamp lighting device has an inverter circuit as a discharge lamp lighting device for lighting a discharge lamp at a high frequency, a filter circuit is provided to remove noise from the inverter circuit. Although this filter circuit removes noise within the range of 526.5 kHz to 30 MHz regulated by the Electrical Appliance and Material Control Law, it does not remove noise with a frequency of 526.5 kHz or less.
[0003]
[Problems to be solved by the invention]
However, the frequency of 526.5 kHz or less is regulated by the international standard CISPR15 and has a problem of causing electromagnetic interference to medical devices even at a frequency of 9 kHz to 526.5 kHz.
[0004]
The present invention has been made in view of the above problems, and an object thereof is to provide a filter circuit, a filter device, and a discharge lamp lighting device that reduce noise of 526.5 kHz or less.
[0005]
[Means for Solving the Problems]
請 filter circuit Motomeko 1 described, a constant voltage element connected to a commercial AC power source; and the two across-the Line capacitor capacitances are connected in parallel is greater than or equal 0.47μF respectively constant voltage element Each of the two across-the- line capacitors has one end connected to both ends of the across-the-line capacitor, and the other across-the-line capacitor has both ends connected to the other ends. The inductances are 0.33 mH, respectively. a grounding capacitor inductance connected to one of the common mode choke is above 2200 pF; above two normal mode choke and; other across the line total inductance is connected and the more common mode choke 8mH across the capacitor With 9kHz to remove the noise of the frequency of 526.5kHz.
[0006]
Filter apparatus of claim 2, wherein the discharge lamp lighting filter circuit of the circuit connected to claims 1, wherein lighting a discharge lamp; which was equipped with a casing that houses the filter circuit, according to claim 1, wherein The noise of 9 kHz to 526.5 kHz is removed by the filter circuit.
[0007]
A discharge lamp lighting device according to claim 3 ; a discharge lamp lighting circuit for lighting the discharge lamp; a normal filter circuit for removing noise of the discharge lamp lighting circuit; and an instrument for storing the discharge lamp lighting circuit and the normal filter circuit The filter device according to claim 2 , wherein a housing is attached to the instrument body, and each function is achieved by attaching the filter device to the instrument body.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first related technique of a discharge lamp lighting device of the present invention will be described with reference to the drawings.
[0009]
FIG. 1 is a circuit diagram showing a filter circuit, FIG. 2 is an explanatory diagram showing a discharge lamp lighting device, and FIG. 3 is a block diagram showing the discharge lamp lighting device. As shown in FIG. 2, reference numeral 1 denotes a chassis as an instrument body. The chassis 1 has a reflecting surface 2 on the lower surface, and a pair of fluorescent lamps 3 and 4 as discharge lamps are mounted on the reflecting surface 2 to reflect the reflecting surface. A line insertion hole 5 is formed in the center of the surface 2. A terminal block 6 is disposed in the vicinity of the line insertion hole 5, and a feed wiring 7 connected to a commercial AC power source e is connected to the terminal block 6.
[0010]
Further, on the back side of the reflecting surface 2, as shown in FIG. 3, a filter device 8 in which a filter circuit 8 shown in FIG. 1 for removing noise having a frequency of 9 kHz to 526.5 kHz out of noise is housed in a housing 9 is housed. The filter unit 10 is connected to the filter base input line 11 on the terminal block 6. Further, a discharge lamp lighting having a discharge lamp lighting circuit (not shown) for lighting the fluorescent lamps 3 and 4 at a high frequency of, for example, 50 kHz or less, and a normal filter circuit for attenuating noise of about 526.5 kHz to 30 MHz from the discharge lamp lighting circuit. A ballast 12 as an apparatus is provided, and this ballast 12 is connected to the filter unit 10 via a filter unit output line 13 and supplies power to the fluorescent lamps 3 and 4 via an output line 14. The length of the filter unit input line 11 from the terminal block 6 to the filter unit 10 is made shorter than the length of the filter unit output line 13 from the filter unit 10 to the ballast 12 so that the filter unit input line 11 As a result, the noise of the filter unit 10 is effectively reduced.
[0011]
Further, as shown in FIG. 1, a normal mode choke L1 having an inductance of 10 mH or more, for example, 10 mH, and a normal mode choke L2 having an inductance of 10 mH or more, for example, 10 mH, are connected from the commercial AC power source e through the feed wiring 7. The normal mode choke L1 is connected to one winding Tr1a of the common mode choke Tr1 having a total inductance of 8 mH or more, for example, 10 mH, and the normal mode choke L2 is connected to the other winding Tr1b of the common mode choke Tr1, It is connected to the ballast 12 via the unit output line 13.
[0012]
Then, the fluorescent lamps 3 and 4 are turned on at a high frequency by the discharge lamp lighting circuit of the ballast 12, and the noise having a frequency of 526.5 kHz to 30 MHz is attenuated by the normal filter circuit.
[0013]
The filter circuit 8 attenuates noise having a frequency of 9 kHz to 526.5 kHz. In this way, noise having a frequency that cannot be attenuated by the normal filter of the ballast 12 is attenuated by the filter circuit 8, thereby complying with the international standard CISPR15 shown in FIG. There is no risk of giving.
[0014]
Further, the filter unit 10 is separated from the ballast 12, the housing 9 in which the filter circuit 8 is accommodated is attached to the chassis 1, and the filter circuit 8 is connected to the feed wiring 7 through the filter unit input line 11. Since it only needs to be connected between the ballast 12 by the base 6 and the filter unit output line 13, the filter circuit 8 can be easily mounted electrically and mechanically later, so that it can be used with existing discharge lamp lighting devices. it can.
[0015]
Next, a second related technique of the present invention will be described with reference to FIG.
[0016]
FIG. 5 is a circuit diagram showing a filter circuit according to the second related art . A normal mode choke having an inductance of 3 mH or more, for example, 3 mH, from the commercial AC power source e through the feed wiring 7, the terminal block 6 and the filter unit input line 11. Similarly, a normal mode choke L4 having an inductance of 3 mH is connected, and the normal mode choke L2 is connected to one winding Tr2a of a common mode choke Tr2 having a total inductance of 8 mH or more, for example, 10 mH, and the normal mode choke L4 is common. Connected to the other winding Tr2b of the mode choke Tr2, and to the other winding Tr2b of the common mode choke Tr2, a grounding capacitor C1 having a capacitance of 2200 pF is connected to the ballast 12 via the filter unit output line 13. It has become so.
[0017]
In the filter circuit 8 shown in FIG. 5, noise having a frequency of 9 kHz to 526.5 kHz is attenuated as shown in FIG. 6, and it corresponds to the standard of the international standard CISPR15.
[0018]
Next, an embodiment will be described with reference to FIG.
[0019]
Figure 7 is a circuit diagram showing a filter circuit of the embodiment, the wiring 7 feed from a commercial AC power source e, through the terminal base 6 and the filter unit input line 11, a series circuit of a fuse F and a constant voltage element Z1 is connected An across-the-line capacitor C2 having a capacitance of 0.47 μF, for example, 0.47 μF, is connected in parallel to the constant voltage element Z1. From both ends of the across-the-line capacitor C2, the inductance is 0.33 mH or more, For example, one end of a normal mode choke L5 of 0.33 mH and one end of a normal mode choke L6 having an inductance of 0.33 mH or more, for example 0.33 mH, are connected. The capacitance between the other ends is 0.47 μF or more, for example, 0.47 μF The across-the-line capacitor C3 is connected, the normal mode choke L5 is connected to one winding Tr3a of the common mode choke Tr3 having a total inductance of 8 mH or more, for example, 10 mH, and the normal mode choke L6 is connected to the other winding of the common mode choke Tr3. A grounding capacitor C4 having a capacitance of 2200 pF is connected to the other winding Tr3b of the common mode choke Tr3 and is connected to the ballast 12 via the filter unit output line 13.
[0020]
In the filter circuit 8 shown in FIG. 7, noise having a frequency of 9 kHz to 526.5 kHz is attenuated as shown in FIG. 8, and this also corresponds to the international standard CISPR15.
[0021]
【The invention's effect】
According to the filter circuit of 請 Motomeko 1, to no 9kHz can remove noise of a frequency of 526.5KHz.
[0022]
According to the filter device of the second aspect, noise having a frequency of 9 kHz to 526.5 kHz can be removed by the filter circuit according to the first aspect.
[0023]
According to the discharge lamp lighting device of the third aspect , each effect can be achieved by attaching the filter device to the instrument body.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing a first related technique of a filter circuit of the present invention.
FIG. 2 is an explanatory view showing the discharge lamp lighting device.
FIG. 3 is a block diagram showing the discharge lamp lighting device.
FIG. 4 is a graph showing the relationship between the frequency and gain of the international standard CISPR15.
FIG. 5 is a circuit diagram showing a filter circuit according to a second related technique of the present invention.
6 is a graph showing attenuation characteristics of the filter circuit shown in FIG.
7 is a circuit diagram showing a filter circuit in the form of Id one embodiment.
FIG. 8 is a graph showing the attenuation characteristics of the filter circuit shown in FIG. 7;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Chassis as an instrument body 3, 4 Fluorescent lamp as a discharge lamp 8 Filter circuit 9 Case
10 Filter unit as a filter device
12 Ballast as discharge lamp lighting device
C2 , C3 across the line capacitor
C4 grounding capacitor
e Commercial AC power supply
L5 , L6 Normal mode choke
Tr3 common mode choke
Z1 constant voltage element

Claims (3)

A constant voltage element connected to a commercial AC power source;
Two across the line capacitors each having a capacitance of 0.47 μF or more respectively connected in parallel to the constant voltage element ;
One end of each of the two across the line capacitors is connected to one end thereof, and the other end is connected to both ends of the other across the line capacitor. The inductance is 0.33 mH or more. And two normal mode chokes;
And the other total inductance is connected to both ends of the across-the Line capacitor is above 8mH common mode choke;
A grounding capacitor connected to one of the common mode chokes and having an inductance of 2200 pF or more;
A filter circuit comprising: Connecting the discharge lamp to the discharge lamp lighting circuit for lighting a filter circuit according to claim 1;
A housing for housing the filter circuit;
A filter device comprising: A discharge lamp lighting circuit for lighting the discharge lamp;
A normal filter circuit for removing noise from the discharge lamp lighting circuit;
An instrument body that houses the discharge lamp lighting circuit and the normal filter circuit;
The filter device according to claim 2 , wherein a housing is attached to the instrument body;
A discharge lamp lighting device comprising:

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